Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
techtalk:ih:oil03p [2021/11/10 07:39] – [Inspect the oil pump cover and body] hippysmacktechtalk:ih:oil03p [2025/02/26 20:36] (current) – hippysmack
Line 1: Line 1:
 [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]] [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]]
 ====== IH: Oiling & Lubrication - Sub-03P ====== ====== IH: Oiling & Lubrication - Sub-03P ======
-====== 77-85 Oil Pump Inspection and Diagnostics ====== +====== 77-85 Oil Pump Inspection ====== 
-\\ +With the replacement of the gear driven oil pump by the new gerotor style pump; \\ HD issued a recommendation to dealers regarding servicing of the new style oil pumps. ((HD Service Bulletin #M-711 dated June 3, 1977)) \\ Zero gerotor (gear) side clearance must be maintained by the flat spring between the upper and lower separator plates for adequate oil pressure. \\ For the spring to function properly, the upper face of the lower feed gerotors must extend slightly above the cover to prevent any side clearance. \\ (which would allow oil to get past the gerotors and reduce oil pressure) \\ If you have reduced oil, no oil pressure (oil light comes on or stays on) or otherwise need to disassemble the oil pump for any reason, \\ The gerotors and their corresponding operating surface in the housing and the cover should be checked and serviced accordingly.
-====== Diagnosing Problems with the Oil Pump ====== +
-Below are some general wear issues as well as secondary issues that may affect the operation of the oil pump. \\ +
-General wear is a given as all moving parts will eventually show an amount of wear. \\ +
-Secondary damage or problems are sometimes not thought of and consist of other parts of or in the motor that may end up damaging the oil pump. \\ +
-**Note: Any time there is a question about the oiling system, FIRST MAKE SURE THERE IS OIL RETURNING TO THE OIL TANK**. \\ +
-If there is no oil returning, do not run the engine any longer until you've discovered why that is. \\ +
-Seeing oil returning to the tank is usually a good thing. It verifies that the return side of the pump is working. ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=1974975&page=13)) \\ +
-(which verifies the drive gear that drives the shaft that drives both pumps is working) \\ +
-On the old gear pumps, it is a pretty good indicator that oil is coming out, so oil must be going in. \\ +
-But on the later gerotor pumps, 1977 onwards and with that big seal between the two halves of the pump, it ain't necessarily so. \\ +
-If the seal between the supply and return pumps is leaking, the return pump is in effect sucking straight from the oil tank, \\ +
-Via the supply pump and leaky seal and is not picking up any air from the sump. Return flow will look fantastic. \\  +
-(better than on a properly functioning oil pump in fact!) \\+
  
- +**Before inspecting any of the parts, clean all the oil and debris from them first**. \\ 
-  * **Possible causes of low or no oil to the motor or oil tank (discussing the oil pump only)**: +Cracks or otherwise damage are sometimes hard to see unless the parts are clean. \\
-    * **Cracked gerotors or too much clearance between the inner and outer gerotors will lower outlet pressure / oil flow to the motor**. \\ The gerotors work by picking up oil from the inlet cavity and moving that oil to the outlet cavity. \\ As the gerotors turn, previous oil deposited in the outlet cavity is pressured to keep moving the next time the outlet cavity is filled on rotation. \\ If there is a crack in a gerotor or a wide clearance between inner and outer gerotors, pressure will be forced into these areas instead. \\ The crack may open up under pressure and let the oil out also. \\ Basically you lose some pressure on the outlet side as some oil is simply being transferred from the outlet side back to the inlet side of the pump. +
-    * **An out of round gerotor bore in the housing or cover can reduce oil pressure**. \\ This equates to too large of clearance around the gerotor OD lessening the hydraulic seal. \\ This can be caused by the separator plates and/or gerotors getting sideways in their bores and wearing the surrounding aluminum.   +
-    * **Air leakage into the pump can result in low oil pressure**. \\ If oil can leak out, air can leak in. Just as the oil return in the tank can be seen in spurts, the feed side also comes in spurts. \\ So there is a small instance of high and low pressure coming from the feed gerotors to outlet pressure. \\ This can equate to a push / pull situation inside the oil pump (both having their own pressure cycles). \\ So the pump can leak oil out of cracks and a quick cycle of vacuum (or reverse pressure) can pull in air from the outside into the pump.  +
-      * **Loose hose clamps at the oil pump and/or oil tank feed hose fittings or split hoses can create air leaks**. \\ If using crimped hose connectors, check them to make sure they are tight. If using worm drive hose clamps, make sure they are tight. \\ Also make sure they haven't been tightened too much (which can cut into the hose under the clamp). \\ This will prevent air leakage into the system which could cause loss of oil pressure due to an airlock in the oil pump. \\ Also periodically check all hoses for rot. +
-      * **Cracks in the pump cover (big or small) at the area of the oil pressure switch are also a source for air intake**. \\ When installing the oil pressure switch, make sure you don't tighten it too much. \\ 5-7 ft/lb (or hand tight plus a nudge) is all it takes to tighten the pressure switch. \\ Much more than that will simply crack the aluminum around the threads. \\ [[techtalk:ih:oil01#oil_pressure_switch|Click Here]] to read more about the oil pressure switch in the Sportsterpedia. +
-      * **The oil pump has to be primed or it will not pump oil**. \\ If you've recently removed the oil pump or feed hose (drained the oil from), air will be present instead. \\ It takes a hydraulic seal around the gerotors to create oil flow/pressure. \\ There have been several reports of work done on the oil pump or an oil pump swap in where no oil flow was noticed during the first ride afterward. \\ Any time the oiling system is worked on, make sure to first check that there is return oil coming back into the oil tank. \\ (especially before risking a no oiling condition on the road) \\ Once the oil pump is initially primed, it should stay primed until such time the pump or feed hose is later removed. +
-    * **Sheared pin on the gearshaft that turns the gerotors**: \\ There are two solid pins (1 for feed side, 1 for return side) on the gearshaft that are responsible for turning the gerotors. \\ Either pin can shear from wear or from a sudden jolt on the oil pump in operation. \\ If on return side, the return gerotors stop turning and oil backs up in the sump (wet sumping to follow). \\ Most if not all the oil in the tank will be pumped into the motor but you'll get no return to the tank. \\ If on the feed side, the oil light should come on (everybody SHOULD have one) to let you know oil is not feeding the motor. \\ The oil tank will stay full with no oil moving about. \\ If both pins shear at the same time.... you've probably already discovered more problems at that point. +
-    *  If the oil lines are ran incorrect, this could stop the oil flow to the motor. +
-    * If the oil pump check valve is blocked or seized in the closed position, you'll get no oil to the motor. +
- +
-  * **General Wear / Damage Issues**: (things to keep in the back of your head when dealing with oiling issues) +
-    * **Gerotors can crack but still work to a point**. \\ That point may be where it finally wears out the pump housing to gerotor OD clearance thus delivering less oil to the motor. \\ There is no spec for gerotor to housing clearance. \\ But even hairline cracks in a gerotor will allow it to expand when hot. \\ This will eat away at the housing bore, heat up the pump and internals causing damage to other pump parts as well. \\ Cracked gerotors will also produce less oil pressure.    +
-    * **Gearshaft pins can shear off, stopping either the feed side or return side or even both from turning**. \\ The solid pins in the side of the gearshaft are responsible for turning the gerotors. \\ The pins will wear and sometimes they will shear off. Each gerotor set has it's own pin. \\ So it's possible for the pin on the return side to shear with the pin on the feed side staying in tact or vice-versa. \\ So you could have feed oil to the motor but no oil return to the tank or vice-versa. \\ Always check for oil returning to the tank when diagnosing any suspected oiling issues (or any time after checking the oil for that matter). \\ Never check oil level without the motor being up to operating temp. \\ So before you shut the motor down to check the oil, have a look in the tank to verify that oil is returning. +
-    * **The roll pin in the oil pump housing can shear or pull out**. \\ This may be due to foreign matter in the feed or return cavities. \\ The feed gerotors are already under pressure due to the spring washer design alone. \\ Any foreign objects that enter the pump can increase the pressure against the outer plate. \\ From the return side, it can push the inner plate toward the feed side. From the feed side, it'll create more pressure on the feed side only. \\ If the extra pressure is enough to grab and spin the plate hard enough, that could be enough to knock the pin out of it's hole in the housing. \\ If the roll pin comes out, it will cause damage to the oil pump. \\ If it gets lodged between the inner and outer gerotors, it'll most likely crack the outer piece (weaker of the two pieces). \\ If it gets under the feed gerotors, it'll get dragged across the gerotor surface in the cover. \\ This will end up in scratches on the machined surface and lower oil pressure from the pump due to the scratches. \\ With the roll pin out, the outer plate under pressure can spin and wallow out the feed bore in the housing around the plate.  +
- +
- +
-====== Oil Pump Inspection ====== +
- +
-With the replacement of the gear driven oil pump by the new gerotor style pump; \\ HD issued a recommendation to dealers regarding servicing of the new style oil pumps. ((HD Service Bulletin #M-711 dated June 3, 1977)) \\ Zero gerotor (gear) side clearance must be maintained by the flat spring between the upper and lower separator plates for adequate oil pressure. \\ For the spring to function properly, the upper face of the lower feed gerotors must extend slightly above the cover to prevent any side clearance. \\ (which would allow oil to get past the gerotors and reduce oil pressure) \\ If you have reduced oil, no oil pressure (oil light comes on or stays on) or otherwise need to disassemble the oil pump for any reason, \\ The gerotors and their corresponding operating surface in the housing and the cover should be checked and serviced accordingly.+
  
 ===== Inspect the oil pump cover and body ===== ===== Inspect the oil pump cover and body =====
  
-=== Look for debris while disassembling ===+==== Look for debris while disassembling ====
  
-Grit / Debris found in the oil pump can give clues to potential motor problems. \\ +Grit / Debris found in the oil pump can give clues to potential motor problems.\\ 
-While removing each part starting from the cover, make note of the color of the oil, any grit or metal particles and what color they are. \\+While removing each part starting from the cover, make note of the color of the oil, any grit or metal particles and what color they are.
  
 +  * What color debris or glitter came from where?
 +      * Yellow or gold (brass/bronze) colored particles/grit: \\ Wrist pin bushings, flywheel thrust washers, rocker arm bushings and cam cover bushings. \\ Non - metallic (can't pick up with a magnet).
 +      * Silver (aluminum) colored particles/grit: \\ Engine case, pistons, oil pump. \\ Non - metallic (can't pick up with a magnet).
 +      * Silver (metal) colored particles/grit: \\ General to excessive metal to metal wear from motor, oil pump drive gear teeth, \\ Broken bearings, races, rods, hardfacing off the rollers and crank pin, crankshaft failure, cam spacer washers, \\ Potentially anything metal from the motor or oil pump. \\ Metallic - (can pick up with magnet).
 +  * Note the size and texture of particles/debris found in the oil pump: \\ Aluminum or metal particles from wear or damage, goopy mush from gasket sealers, colored chips from a recent paint job, gasket material, rags or other.
 +  * Which side of the pump is it in, feed or return?: \\ Debris in the return side came out of the motor into the pump. \\ Debris in the feed side came from the oil tank (which most likely came from the motor to the oil tank). \\ For long term diagnosis, this may not find a smoking gun problem. \\ But in cases of sudden failure, it may be an important clue as in where to start looking for problems.
   * Silicone should not be used anywhere on a Sportster motor. \\ If so, you may find pieces of it in the oil pump or in the small orifics and oil galleys within the motor. \\ The push / pull of crankcase pressure can implode gaskets and especially sealants like silicone. \\ This will stop up the oil paths in the motor and if caught early enough, can be flushed out before catastrophic damage happens.   * Silicone should not be used anywhere on a Sportster motor. \\ If so, you may find pieces of it in the oil pump or in the small orifics and oil galleys within the motor. \\ The push / pull of crankcase pressure can implode gaskets and especially sealants like silicone. \\ This will stop up the oil paths in the motor and if caught early enough, can be flushed out before catastrophic damage happens.
-  * Visually inspect the inside of the check valve to make sure the little disc up inside it is fully closed. \\ Loose metal particles can get stuck between the disc and the valve body keeping the disc from closing. \\ If you find metal debris in the check valve, there may also be metal that made it's way past the check into the motor.   
  
-|Silicone 'gummy bear' sheet found in the feed side|Oil check valve stuck open with metal debris ((photo by Screwloose of the XLFORUM http://xlforum.net/forums/showthread.php?t=1979566))| +|Silicone 'gummy bear' sheet found in the feed side ((photo by (-_-) of the XLFORUM, annotated by Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/efi-sportster-motorcycle-talk-2007-and-up/198113-help-me-figure-out-weird-engine-braking/page3?t=2074835&page=3))  | 
-|{{:techtalk:evo:oil:oil_pump_damage_3_by_-_-_-_annotated.jpg?direct&300|}} ((photo by (-_-) of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=2074835&page=3))|{{:techtalk:ih:oil:1977-1985_oil_pump_check_valve_by_screwloose.jpg?direct&300|}}|+|{{:techtalk:evo:oil:oil_pump_damage_3_by_-_-_-_annotated.jpg?direct&300}}|
  
-=== Inspect the ridge in the cover ===+==== Inspect the ridge in the cover ====
  
-      * Using a straightedge across the feed gerotor set (installed) surface; \\ Measurement should be taken with a feeler gauge from the gerotor surface to the ridge of the edge of the aluminum cover. \\ The thin, feed gerotors (26492-75) in the oil pump cover (26486-75) should extend .001"-.005" above the cover's aluminum ridge. \\ The later feed gerotors extend up to .011" above the ridge. \\ If the feed gerotors do not extend above the ridge within the specified range, \\ Remove and sand the ridge evenly until the gerotors extend properly when inserted. \\ Lay some sandpaper on a flat surface (#280 grit then #400 grit to finish). \\ Invert the cover and sand the ridge then check the measurement with a micrometer. \\ Make sure that both the inner and outer gerotors are the same thickness also.+  * Using a straightedge across the feed gerotor set (installed) surface; \\ Measurement should be taken with a feeler gauge from the gerotor surface to the ridge of the edge of the aluminum cover. \\ The thin, feed gerotors (26492-75) in the oil pump cover (26486-75) should extend .001"-.005" above the cover's aluminum ridge. \\ The later feed gerotors extend up to .011" above the ridge. \\ If the feed gerotors do not extend above the ridge within the specified range, \\ Remove and sand the ridge evenly until the gerotors extend properly when inserted. \\ Lay some sandpaper on a flat surface (#280 grit then #400 grit to finish). \\ Invert the cover and sand the ridge then check the measurement with a micrometer. \\ Make sure that both the inner and outer gerotors are the same thickness also.
  
-{{:techtalk:ih:oil:1977-1985_oil_pump_cover-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\+{{:techtalk:ih:oil:1977-1985_oil_pump_cover-_checking_clearance_by_hippysmack.jpg?direct&300}}((photo by Hippysmack))
  
-=== Inspect the gerotor surface for flatness in the oil pump cover and housing ===+==== Inspect the gerotor surface for flatness in the oil pump cover and housing ====
  
-An oil pump cover found with an uneven gerotor surface should be removed. \\ +An oil pump cover found with an uneven gerotor surface should be removed. \\ If the gerotor widths measure equally but they are not equal in height when placed into the cover, the cover surface is not flat. \\ If the gerotors will not sit flat in the cover then the cover should be replaced. \\ Be sure to check the gerotors in the new/replacement cover using a straight­ edge to assure a level surface and the proper elevation above the ridge. \\ Be sure to check the gerotor surface in the housing also.
-If the gerotor widths measure equally but they are not equal in height when placed into the cover, the cover surface is not flat. \\ +
-If the gerotors will not sit flat in the cover then the cover should be replaced. \\  +
-Be sure to check the gerotors in the new/replacement cover using a straight­ edge to assure a level surface and the proper elevation above the ridge. \\ +
-Be sure to check the gerotor surface in the housing also.+
  
-=== Inspect the gerotor surface in the cover and housing for deep scratches or gouges ===+==== Inspect the gerotor surface in the cover and housing for deep scratches or gouges ====
  
-Many (most perhaps) used oil pumps have scratches on both the gerotors and pump surfaces that the gerotors ride on. \\  +Many (most perhaps) used oil pumps have scratches on both the gerotors and pump surfaces that the gerotors ride on. \\ But, there is one certain spot that seems to be scratched more times than others. ((Hippysmack of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/194881-let-s-study-the-77-85-oil-pump-parts-and-changes-and-when/page6?t=2071153&page=6))   \\ It's on the larger of the two pads in the pump body and the cover seem to usually have more wear. \\ Sometimes, the small pad is scratched or damaged also but not always. \\ The gap between the inner and outer gerotors on both the feed and return sides tends to be scratched as in the pics below. \\ Debris caught between these two gears cannot slide over and fall to the other cavity and out of the pump. \\ It gets locked between the teeth and ripped across the aluminum surface. \\ In theory, no particles of any size should be able to spin around to the small pad. \\ This is mainly due to the pressure generated by the spring washer and the gerotor spacing there. \\ Also, any debris picked up from the source side cavity should drop down into the feed side cavity and out of the pump. \\ The side toward the motor is where oil is transferred to and from the pump. \\ The inner and outer gerotors come together on the other side (right side). \\ This spacing relationship doesn't change between the motor side or the outside of the pump due to the offset gearshaft. \\ But in reality, debris gets caught in or between the gears and gets dragged over the aluminum flats. \\ Some then find their way under the gerotors while the spring washer flexes from the stress. \\ The debris spins around under the gerotors and wears scratches in the flats (pads) or worse. \\ There should be some amount of reduced pressure because of the scratches (depending on how may and how deep). \\ Pressure generated to the output cavity can squirt back to the input side through these scratches. \\ How much pressure loss would depend on the width, depth, length of the scratches and oil viscosity at the time. \\ To make the pump inoperative or not make pressure (from the scratches alone); \\ The scratches would have to be proportional to the relative volume of all four gerotor reservoirs combined. \\ Then, the check valve would have to accept less pressure flow than the backpressure from the pump. \\ The gerotor surface in the cover would have to be eat up pretty bad to make the pump completely ineffective. \\ The pump would have less pressure loss with multi-weight or straight weight oil when cold than hot. \\ They'll both flow faster when hot. \\ | Gerotor rotation (cover shown) ((photos by Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/194881-let-s-study-the-77-85-oil-pump-parts-and-changes-and-when/page6?t=2071153&page=6))  ||
-But, there is one certain spot that seems to be scratched more times than others. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2071153&page=6)) \\ +
-It's on the larger of the two pads in the pump body and the cover seem to usually have more wear. \\ +
-Sometimes, the small pad is scratched or damaged also but not always. \\ +
-The gap between the inner and outer gerotors on both the feed and return sides tends to be scratched as in the pics below. \\ +
-Debris caught between these two gears cannot slide over and fall to the other cavity and out of the pump. \\ +
-It gets locked between the teeth and ripped across the aluminum surface. \\+
  
-In theory, no particles of any size should be able to spin around to the small pad. \\ +|{{:techtalk:ih:oil:77-85_oil_pump_cover_9a_by_hippysmack.jpg?direct&300}}|{{:techtalk:ih:oil:77-85_oil_pump_cover_10a_by_hippysmack.jpg?direct&300}}|
-This is mainly due to the pressure generated by the spring washer and the gerotor spacing there. \\ +
-Also, any debris picked up from the source side cavity should drop down into the feed side cavity and out of the pump. \\ +
-The side toward the motor is where oil is transferred to and from the pump. \\ +
-The inner and outer gerotors come together on the other side (right side). \\ +
-This spacing relationship doesn't change between the motor side or the outside of the pump due to the offset gearshaft. \\+
  
-But in reality, debris gets caught in or between the gears and gets dragged over the aluminum flats. \\ +{{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_1_by_hippysmack.jpg?direct&300}}{{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_2_by_hippysmack.jpg?direct&300}}{{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_3_by_hippysmack.jpg?direct&300}}
-Some then find their way under the gerotors while the spring washer flexes from the stress. \\ +
-The debris spins around under the gerotors and wears scratches in the flats (pads) or worse. \\+
  
-There should be some amount of reduced pressure because of the scratches (depending on how may and how deep). \\ +==== Classifying Scratches in Gerotor Surfaces ====
-Pressure generated to the output cavity can squirt back to the input side through these scratches. \\ +
-How much pressure loss would depend on the width, depth, length of the scratches and oil viscosity at the time. \\ +
-To make the pump inoperative or not make pressure (from the scratches alone); \\ +
-The scratches would have to be proportional to the relative volume of all four gerotor reservoirs combined. \\ +
-Then, the check valve would have to accept less pressure flow than the backpressure from the pump. \\ +
-The gerotor surface in the cover would have to be eat up pretty bad to make the pump completely ineffective. \\ +
-The pump would have less pressure loss with multi-weight or straight weight oil when cold than hot. \\ +
-They'll both flow faster when hot. \\+
  
-|  Gerotor rotation (cover shown) ((photos by Hippysmack http://xlforum.net/forums/showthread.php?t=2071153&page=6))  || +HD says that if there are any notable scratches on the gerotor riding surfaces in the oil pump housing or cover, then they should be replaced. \\ Hagen–Poiseuille Equation to calculate flow pressure drop: ((Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/203901-sportster-oil-pressure-and-dynamics/page9))   \\ Without getting into the weeds on figures (that change with every individual pump), Hagen/Poiseuille determined that the laminar flow rate of an incompressible fluid along a pipe is proportional to the fourth power of the pipe's radius. That is, doubling the diameter of an outlet increases the flow rate by 16 fold (r4). The larger the outlet, the greater the flow. But in the instance of pump internal leakage, there are two outlets, upstream back to the inlet and downstream into the engine. \\ Result: In order for the pump to not produce any flow to the outlet side (downstream), total ID of the clearances and scratches would have to be twice the ID of the outlet of the pump using Hagen/Poiseuille. \\ 
-|{{:techtalk:ih:oil:77-85_oil_pump_cover_9a_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ih:oil:77-85_oil_pump_cover_10a_by_hippysmack.jpg?direct&300|}}|+
  
-{{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_1_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_2_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:1977-e1983_oil_pump_body_scratches_3_by_hippysmack.jpg?direct&300|}} \\ +Further comments by Hippysmack. In thinking about it;
- +
-=== Classifying Scratches in Gerotor Surfaces  === +
- +
-HD says that if there are any notable scratches on the gerotor riding surfaces in the oil pump housing or cover, then they should be replaced. \\ +
- +
-Further comments by Hippysmack: \\ +
- +
-<blockquote>In thinking about it;+
   * Inlet side of the pump feed cavity is first fed by gravity from the oil tank and then by suction assist (vacuum pressure) created by the spinning feed gerotors.   * Inlet side of the pump feed cavity is first fed by gravity from the oil tank and then by suction assist (vacuum pressure) created by the spinning feed gerotors.
   * Inlet side of the pump return cavity is fed solely on suction from the spinning return gerotors. \\ Oil is sucked uphill from the crankcase sump thru a small drilled oil galley in the case to the oil pump.   * Inlet side of the pump return cavity is fed solely on suction from the spinning return gerotors. \\ Oil is sucked uphill from the crankcase sump thru a small drilled oil galley in the case to the oil pump.
Line 115: Line 54:
   * There is a certain amount of intermittent pressure lost by design on every gerotor tooth rotation. \\ This is more prevalent on the feed side than return due to back pressure further up the feed oil path. \\ When a tooth first enters the rather long inlet cavity, pressure starts building as it rotates around the end of that cavity. \\ Until the feed tooth is fully over the big pad in the cover, some oil squirts back into the inlet cavity from backpressure. \\ Once the tooth is fully on top of the big pad, pressure builds from there as it rotates toward the outlet cavity. \\ Oil is transferred out the pump from there and the pressure in that side of the gerotor is relieved until the next rotation.   * There is a certain amount of intermittent pressure lost by design on every gerotor tooth rotation. \\ This is more prevalent on the feed side than return due to back pressure further up the feed oil path. \\ When a tooth first enters the rather long inlet cavity, pressure starts building as it rotates around the end of that cavity. \\ Until the feed tooth is fully over the big pad in the cover, some oil squirts back into the inlet cavity from backpressure. \\ Once the tooth is fully on top of the big pad, pressure builds from there as it rotates toward the outlet cavity. \\ Oil is transferred out the pump from there and the pressure in that side of the gerotor is relieved until the next rotation.
   * Elongated scratches in these pads allow a constant amount of generated pressure on the outlet side to squirt back to the inlet side of the pump. \\ This will lower the pressure to the extent of how deep the scratches are. \\ Deep scratches allow more oil pressure or oil flow to recirculate from the outlet back to the inlet within the oil pump. \\ This makes for less oil gauge pressure on the feed side as well as less oil flow to the motor. \\ This makes for less oil flow back to the oil tank.   * Elongated scratches in these pads allow a constant amount of generated pressure on the outlet side to squirt back to the inlet side of the pump. \\ This will lower the pressure to the extent of how deep the scratches are. \\ Deep scratches allow more oil pressure or oil flow to recirculate from the outlet back to the inlet within the oil pump. \\ This makes for less oil gauge pressure on the feed side as well as less oil flow to the motor. \\ This makes for less oil flow back to the oil tank.
-  * How many scratches or how deep the scratches need to be before the pump housing/cover needs to be replaced has never been publicized by the MoCo. \\ They apparently didn't want to get into the weeds... as I've done here. +  * How many scratches or how deep the scratches need to be before the pump housing/cover needs to be replaced has never been publicized by the MoCo. \\ They apparently didn't want to get into the weeds… as I've done here. 
-  * Backpressure is greater on the feed side than it is the return side. \\ The feed path from the pump has many turns and restrictions that build pressure. \\ Since oil is not compressible, it can't absorb any of that pressure. \\ So excess pressure is sent backwards from the restrictions. \\ This is how oil can recirculate form the feed outlet back to the feed inlet through out of service clearances and oil pump pad wear. \\ When the pressure is reverted backward, it runs back to the inlet side of the pump. \\ If backpressure is allowed to constantly run back to the inlet side, it will send oil back up the feed hose. \\ If you normally would have say 4psi at idle on the pump outlet, you'd now have 2 psi on the outlet and 2 psi going back to the inlet.+  * Backpressure is greater on the feed side than it is the return side. \\ The feed path from the pump has many turns and restrictions that build pressure. \\ Since oil is not compressible, it can't absorb any of that pressure. \\ So excess pressure is sent backwards from the restrictions. \\ This is how oil can recirculate from the feed outlet back to the feed inlet through out of service clearances and oil pump pad wear. \\ When the pressure is reverted backward, it runs back to the inlet side of the pump. \\ If backpressure is allowed to constantly run back to the inlet side, it will send oil back up the feed hose. \\ If you normally would have say 4psi at idle on the pump outlet, you'd now have 2 psi on the outlet and 2 psi going back to the inlet.
   * Consequently, more oil will recirculate thru the feed side than the return side if both big pads have identical width and depth elongated scratches. \\ The backpressure from the feed side would push more oil faster under the gerotors than the return side with less backpressure. \\ If the oil tank vent line is stopped up, backpressure on the return side of the pump will be greater and send more oil under the gerotors back to the sump.   * Consequently, more oil will recirculate thru the feed side than the return side if both big pads have identical width and depth elongated scratches. \\ The backpressure from the feed side would push more oil faster under the gerotors than the return side with less backpressure. \\ If the oil tank vent line is stopped up, backpressure on the return side of the pump will be greater and send more oil under the gerotors back to the sump.
   * I'd guesstimate that there are a whole lot of Sportsters on the road with motors having gerotor pumps with various degrees of scratches. \\ The fact that there hasn't been a lot of talk on degrees of scratches in the oil pump says that most probably don't worry too much about them. \\ But then, you end up seeing that one complete teardown due to an oil pump problem and you get to wondering yourself.   * I'd guesstimate that there are a whole lot of Sportsters on the road with motors having gerotor pumps with various degrees of scratches. \\ The fact that there hasn't been a lot of talk on degrees of scratches in the oil pump says that most probably don't worry too much about them. \\ But then, you end up seeing that one complete teardown due to an oil pump problem and you get to wondering yourself.
-  * There is only one way to answer that question. You have to do some pressure testing. \\ [[techtalk:ih:oil01#engine_oil_pressure_57-85|Click Here]] to see expected oil pressure when tested with an oil gauge. \\ [[techtalk:ref:oil15|Click Here]] to see the page in the Sportsterpedia on how to install an oil gauge. \\ Checking oil pressure should be routine maintenance. You can measure the current oil pressure and keep a log on future pressure changes. \\ Hot oil pressure isn't that much at idle even with a new oil pump. Oil pump wear will lower that reading. \\ In fact, the figures in the FSM for expected oil pressure do assume the pump is in good (non worn) shape. \\ If pressure is low, you might want to look into the oil pump or other points along the oil path. \\ Low pressure doesn't immediately mean the housing or cover is scratched too bad. \\ But if you take a reading, replace the pump and take a new reading.... that does tell you something.  +  * There is only one way to answer that question. You have to do some pressure testing. \\ [[:techtalk:ih:oil01#engine_oil_pressure_57-85|Click Here]] to see expected oil pressure when tested with an oil gauge. \\  [[:techtalk:ref:oil15|Click Here]] to see the page in the Sportsterpedia on how to install an oil gauge. \\  Checking oil pressure should be routine maintenance. You can measure the current oil pressure and keep a log on future pressure changes. \\  Hot oil pressure isn't that much at idle even with a new oil pump. Oil pump wear will lower that reading. \\  In fact, the figures in the FSM for expected oil pressure do assume the pump is in good (non worn) shape. \\  If pressure is low, you might want to look into the oil pump or other points along the oil path. \\  Low pressure doesn't immediately mean the housing or cover is scratched too bad. \\  But if you take a reading, replace the pump and take a new reading…. that does tell you something. 
-  * Maybe this will give more people cause to think on the subject of how much is too much or how little is just fine.  +  * Maybe this will give more people cause to think on the subject of how much is too much or how little is just fine.
-</blockquote>+
  
-Below are a few used oil pumps showing scratches of varying degrees. Further comments are posted on top of the pics. \\ +Below are a few used oil pumps showing scratches of varying degrees. Further comments are posted on top of the pics. \\ These are simply observations and it's up to the individual to decide how much wear on the gerotor surfaces in the oil pump are acceptable. \\ Any marked reusable should still be pressure tested and observed if you'll be using them. \\ |Metal chunk lodged in return inlet. \\ The one medium scratch on big pad is some concern. \\ Small amount of recirculation oil internally. \\ Metal debris lessens amount of pickup oil at once. \\ May be reusable with further observation ((photo by sc72 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/160106-where-to-go-from-here/page15?t=1717592&page=15))  |Deep and wide channel ripped into big pad. \\ Light scratches across small pad. \\ High possibility of recirculating oil internally, \\ (feed outlet to feed inlet thru big pad scratch) \\ Owner said oil was not returning. \\ Should be replaced. ((photo by Rolli of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/201663-1983-ironhead-oil-not-returning?highlight=oil+pump#post4475667))  |A gearshaft pin sheared and got into the return cavity. \\ It broke out a corner of the big pad. \\ The remaining flat surface of pad is undamaged. \\ Should be reusable with further observation. ((photo by DirtyCory of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/127032-getting-this-78-back-to-the-way-it-should-be/page2?t=1297584&page=2))  |
-These are simply observations and it's up to the individual to decide how much wear on the gerotor surfaces in the oil pump are acceptable. \\ +
-Any marked reusable should still be pressure tested and observed if you'll be using them. \\+
  
-|Metal chunk lodged in return inlet. \\ The one medium scratch on big pad is some concern. \\ Small amount of recirculation oil internally. \\ Metal debris lessens amount of pickup oil at once.  \\ May be reusable with further observation ((photo by sc72 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1717592&page=15))|Deep and wide channel ripped into big pad. \\ Light scratches across small pad. \\ High possibility of recirculating oil internally, \\ (feed outlet to feed inlet thru big pad scratch) \\ Owner said oil was not returning. \\ Should be replaced. ((photo by Rolli of the XLFORUM http://xlforum.net/forums/showthread.php?p=5877838&highlight=oil+pump#post5877838))|A gearshaft pin sheared and got into the return cavity. \\ It broke out a corner of the big pad. \\ The remaining flat surface of pad is undamaged. \\ Should be reusable with further observation. ((photo by DirtyCory of the XLFORUM http://xlforum.net/forums/showthread.php?t=1297584&page=2))| +|{{:techtalk:ih:oil:1983_sportster_oil_pump_body_by_sc72.jpg?direct&300}}|{{:techtalk:ih:oil:1977-e1983_oil_pump_scratches_by_rolli.jpg?direct&300}}|{{:techtalk:ih:oil:1978_oil_pump_body_by_dirtycory.jpg?direct&300}}|
-|{{:techtalk:ih:oil:1983_sportster_oil_pump_body_by_sc72.jpg?direct&300|}}|{{:techtalk:ih:oil:1977-e1983_oil_pump_scratches_by_rolli.jpg?direct&300|}}|{{:techtalk:ih:oil:1978_oil_pump_body_by_dirtycory.jpg?direct&300|}}|+
  
-=== Check for cracks in the housing and cover ===+==== Check for cracks in the housing and cover ====
  
-The cover below was cracked at the oil pressure switch end from tightening the pressure switch too tight. \\  +The cover below was cracked at the oil pressure switch end from tightening the pressure switch too tight. \\ The crack was welded over and a Dremil tool was used to reshape the cover. \\ Due to warpage during welding, the threads need to be chased with a tap to straighten them back out.
-The crack was welded over and a Dremil tool was used to reshape the cover. \\ +
-Due to warpage during welding, the threads need to be chased with a tap to straighten them back out. \\+
  
-|  Repair on oil pump cover ((photos by acb2 of the XLFORUM http://xlforum.net/forums/showthread.php?t=554323))  ||  Oil Switch Torque ((drawing by Hippysmack))  | +|  Repair on oil pump cover ((photos by acb2 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/77330-oil-pump-1977-up?t=554323)) </sup>    ||  Oil Switch Torque ((drawing by Hippysmack)) </sup>    | 
-|{{:techtalk:ih:oil:cracked_oil_pump_cover_1_by_acb2.jpg?direct&300|}}|{{:techtalk:ih:oil:cracked_oil_pump_cover_2_by_acb2.jpg?direct&300|}}|{{:techtalk:evo:oil:oil_pressure_switch_threads_by_hippysmack.png?direct&300|}}|+|{{:techtalk:ih:oil:cracked_oil_pump_cover_1_by_acb2.jpg?direct&300}}|{{:techtalk:ih:oil:cracked_oil_pump_cover_2_by_acb2.jpg?direct&300}}|{{:techtalk:evo:oil:oil_pressure_switch_threads_by_hippysmack.png?direct&300}}|
  
-=== Inspect the Housing Roll Pin ===+==== Inspect the Housing Roll Pin ====
  
-The roll pin is installed into the "shelf" between the housing bores and it normally shouldn't see any shear force. \\ +The roll pin is installed into the "shelf" between the housing bores and it normally shouldn't see any shear force. \\ A roll pin is a spring, that's what keeps it in place. It's not solid because it's NOT supposed to shear. ((kitabel of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203361-oil-pump-split-pin-removal))
-All internals depend on the strength of the solid pins, and the drive gear. \\ +
-The outer separator plate has a slot in it that installs over the roll pin. \\  +
-Normally the only force on the roll pin is stationary pressure from the outer plate wanting to turn with the feed gerotor under it. \\ +
-However, sudden jolts or back pressure on the pump can strengthen that stationary pressure against the roll pin and either pull it out or shear it off. \\ +
-Give the roll pin a slight tug with needle nose pliers to make sure it is good and pressed in and doesn't want to wiggle. \\ +
-If there is any looseness or wiggle, pull it out and replace it now so you don't find it inside the motor later. \\+
  
-{{:techtalk:ih:oil:77-85_oil_pump_body_7_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\+The scavenge gerotor is not quite as tall as the "shelf" where the inner plate sits. \\ Normally, there is a slight gap between the return gerotor set and the inner plate. Inner plate sits against the shelf, not the return gerotors. \\ When you button up the pump and the spring washer tightens the turning of the gearshaft, it's tightening against the feed gerotors, not return. \\ So the return side should be free to move up and down with RPM and float off the plate.
  
-===== Inspect the gearshaft and bushings for damage or wear =====+The separator (divider) plates have a slot on their OD that installs over the roll pin. \\ Normally the only force on the roll pin is stationary pressure from the outer plate wanting to turn with the feed gerotor under it. \\ However, sudden jolts or back pressure on the pump can strengthen that stationary pressure against the roll pin. \\ The roll pin in the oil pump housing can be damaged (by the parts in the pump getting in a bind) or by a previous hamfisted pump assembly. \\ The pin can be punished by the divider plates enough to wallow the hole it's in and/or damaging the hole enough to loosen the pin. \\ This may be due to foreign matter in the feed or return cavities. \\ Any foreign objects that enter the pump can increase the pressure against the plates to move. \\ Or the pin can be damaged from simply trying to remove it.
  
-    * Check the gear teeth for pits, breakage or wear. Replace the gearshaft as necessary.+The hole in the center of the divider plates is off center. The roll pin locates the plates to the housing and the off centered drive shaft. 
 + 
 +**Check the roll pin**. \\ Give the roll pin a slight tug with needle nose pliers to make sure it is good and pressed in and doesn't want to wiggle. \\ If there is any looseness or wiggle, pull it out and replace it now so you don't find it inside the motor later. 
 + 
 +There is nothing wrong with the roll pin in this photo. \\ {{:techtalk:ih:oil:77-85_oil_pump_body_7_by_hippysmack.jpg?direct&300}}((photo by Hippysmack))   \\  \\ 
 + 
 +If the roll pin comes out, it will cause damage to the oil pump. If it gets lodged between the inner and outer gerotors, it'll most likely crack the outer piece (weaker of the two pieces). If it gets under the gerotors, it'll get dragged across the gerotor surface in the pump housing or cover. This will end up in scratches on the machined surface and lower oil pressure from the pump due to the scratches. With the roll pin out, the outer plate, under pressure, can spin and wallow out the feed bore in the housing around the plate. 
 + 
 + 
 +**If needed, below are some possible ways to remove the roll pin**. \\ 
 +Note: Vise Grips will most likely slip off the pin and damage it further, but more importantly damage the pump housing. Heat will most likely expand the aluminum around the pin, squeezing it harder around the pin. these are generally bad ideas for removing the pin. 
 + 
 +  - You can try a side dike wire cutter and a little electrical freeze spray on the aluminum. 
 +  - You could try running a small tap into the roll pin to cut threads for a small screw, then screw the bolt into the center. \\ Once the bolt hits bottom of the hole, it may push the pin up and out or at least loosen the pin. ((Andy Hog of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203361-oil-pump-split-pin-removal)) 
 +  - You may or may not need to cut the buggered part off, but you could try to fill the pin with oil and insert a close fitting punch into the hole. The hit the punch with a hammer. The hammer blow may move the pin upward. ((sungod of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203361-oil-pump-split-pin-removal)) 
 +  - This is tedious but would work, if done properly and with a steady hand. \\ This method may also be used if the existing hole is broken out or the is wallowed to where a new pin would not tighten up to the existing hole. You could carefully cut the old pin flush with a Dremil tool, leave the old pin where it is and install a new pin elsewhere. Note: if you drill a new pin hole you must cut new slots in the 2 plates that the pin locates. ((needspeed of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203361-oil-pump-split-pin-removal/page2))  You can't rotate the plates into a different position because the hole in the plates that the shaft goes through is not exactly in the middle (off centered). 
 +      * First, remove the guts inside and install both divider plates over the old pin to locate them properly. Then drill a small hole (smaller than the pin hole) thru the top plate, thru to the bottom plate and stop when it is dimpled by the drill bit. Remove the plates and finish drilling the second plate. Then use a Dremil tool or file to cut a slot from edge of plate to hole (on ea plate) 
 +      * Reinstall both plates and drill thru the new slots in both to make a dimple in the pump housing, remove plates. 
 +      * Drill hole in pump housing to depth of new pin (correct bore size for new pin). \\ It's good to have an index drill bit set (especially for smaller bits). Most drill bits will wallow a hole bigger than what it is written on the bit. Start with a slightly smaller bit than (projected installed OD of the pin dia) into the plates and just enough into the housing to make a dot. Then pull it back apart and square up the housing using the same drill bit. Measure it and drill with bigger bit if needed for the pin. If you drill too wide, the pin won't stay. Roll pins are sized by the dia of the hole needed (1/8" roll pin for 1/8" hole) but the pin will measure bigger than that. Just need to make sure the hole doesn't wallow. 
 +      * Use a metal cutting blade on a Dremil cutting tool to cut the old pin flush with the "shelf" in the pump housing. Make sure there are no splinters left on the existing pin (needs to be flush to the shelf it sits on) and the shelf has no gouges that would push on the divider plates when installed. 
 +      * Blow out the new hole with compressed air, press the new roll pin into the new hole and you're done. 
 + 
 +**The roll pin below was damaged by trying to remove it**. \\ It was removed using electrical side cutters by XLF member, billeuze. ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203361-oil-pump-split-pin-removal/page2))   \\ Carefully protect the base and sides of the pump body. \\ Odd parts were put inside the pump for a nice height for a fulcrum for the side cutters. \\ I squeezed and pried it out. It took 4 or five pries to walk it all the way out. ((photos by billeuze)) 
 + 
 +{{:techtalk:ih:oil:1977-e1983_sportster_oil_pump_roll_pin_removal_pic1_by_billeuze.jpg?direct&400}}{{:techtalk:ih:oil:1977-e1983_sportster_oil_pump_roll_pin_removal_pic2_by_billeuze.jpg?direct&400}} 
 + 
 +{{:techtalk:ih:oil:1977-e1983_sportster_oil_pump_roll_pin_removal_pic3_by_billeuze.jpg?direct&400}}{{:techtalk:ih:oil:1977-e1983_sportster_oil_pump_roll_pin_removal_pic4_by_billeuze.jpg?direct&400}} 
 +\\ 
 + 
 +**The roll pin below was damaged and a second roll pin was added to keep from removing the original pin**. \\ 
 +In order to add the second pin, additional slots have to be cut into both the inner and outer plates since they are both captured by the roll pin. \\ 
 +{{:techtalk:ih:oil:1980_oil_pump_pin_and_divider_plate_mod_pic1_by_billy1200.jpg?direct&400|}} {{:techtalk:ih:oil:1980_oil_pump_pin_and_divider_plate_mod_pic2_by_billy1200.jpg?direct&400|}} \\ 
 + 
 +===== Inspect the gearshaft and bushings for damage or wear ===== 
 +    * Check the gearshaft teeth for pits, breakage or wear. Replace the gearshaft as necessary. \\ Also do not forget to check the teeth on the oil pump drive gear on the pinion shaft. \\ If the teeth on it are thin, replace the drive gear. \\ Pinion shaft runout can wear the drive gear teeth down thin enough to break off and float with the oil.
     * Clean areas where the shaft sits in a bushing with steel wool if needed. \\ If it's not possible to smooth the areas out, replace the shaft.     * Clean areas where the shaft sits in a bushing with steel wool if needed. \\ If it's not possible to smooth the areas out, replace the shaft.
     * Inspect the gearshaft bushings both the housing and the cover. \\ Look for scoring, excess wear and noticeable damage. Replace as necessary.     * Inspect the gearshaft bushings both the housing and the cover. \\ Look for scoring, excess wear and noticeable damage. Replace as necessary.
 +    * Check for a warped or seized bushing around the gearshaft. \\ The gearshaft should spin easily in the bushing without bumps or grinding. \\ Pull the spring washer out of the pump, reassemble without the spring and lightly spin the gearshaft listening for noises and feeling for smooth turning. \\ The only thing may make an oil pump bushing seize is if the oil lines are connected backwards (or low oil supply) creating heat around them. 
     * Measure the gearshaft to bushing clearance on both the upper and lower bushings (maximum .0005"). \\ Replace any bushing with a clearance larger than that.     * Measure the gearshaft to bushing clearance on both the upper and lower bushings (maximum .0005"). \\ Replace any bushing with a clearance larger than that.
       * Clean the bushings and gearshaft of all oil / residue before measuring.       * Clean the bushings and gearshaft of all oil / residue before measuring.
Line 168: Line 130:
 \\ \\
  
-The solid pins in the gearshaft may be different lengths and/or different OD. \\ +===== Gerotor shear pins ===== 
-There is no spec for the pins in the service manual. The pins main function is to turn the gerotors. \\ +  * The solid shear pins in the gearshaft may be different lengths and/or different OD. \\ There is no spec for the pins in the service manual. 
-And the gerotors are much taller than the pin thickness. So the height of the slot allows a fudge factor on quick throttle blips. \\ +  * The pins main function is to turn the gerotors. \\ Pin construction is designed to be the weak point and let go if the pump gets jammed with solid objects. \\ (like bits of metal etc in the gears, or if the oil pump bushings seize etc). 
-The pins are not pressed into the gearshaft but just a slip fit. \\ +  * Just putting a new shear pin back in without fully rebuilding the pump and checking for jamming or seizing is begging for the same thing to happen again. ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/49875-heeeeeeeeeeelpppp-meeeeeeeeee-motor-dying-in-4th-gear/page2#post1049264)) 
-Also the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ +  * The gerotors are much taller than the pin thickness. 
-Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ +  * So the height of the slot allows a fudge factor on quick throttle blips and the gerotors won't be affected. \\ The gearshaft will rise some on higher throttle and there is built in "up and down" clearance in the pump to allow this. \\ 
-You can buy a handful of new pins only to find they are all different dims as well. \\ +  * The pins are not pressed into the gearshaft and the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ You can buy a handful of new pins only to find they are all different dims as well. \\ If you find real slop in the pin fit to the gearshaft, either replace the pins and/or the gearshaft. \\ Do not buy hardened pins as that will defeat the purpose of the "shear pin" design. If the pins only protrude slightly into the gerotor slots, use longer pins. \\
-If you find real slop in the pin fit to the pins, either replace the pins and/or the gearshaft. \\ +
-If the pins only protrude slightly into the gerotor slots, use longer pins. \\+
  
-This are used parts but shows the pin locations and how they look installed with a gerotor on the shaft. \\+The pics below are used parts but show the pin locations and how they look installed with a gerotor on the shaft. \\
 Pins align with the square slot in the gerotors. ((photos by Hippysmack)) \\ Pins align with the square slot in the gerotors. ((photos by Hippysmack)) \\
  
 {{:techtalk:ih:oil:1977-1985_oil_pump_gearshaft_pins_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_3_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_5_by_hippysmack.jpg?direct&300|}} \\   {{:techtalk:ih:oil:1977-1985_oil_pump_gearshaft_pins_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_3_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_5_by_hippysmack.jpg?direct&300|}} \\  
- 
  
 ===== Inspect both gerotor sets ===== ===== Inspect both gerotor sets =====
-Clean both gerotor sets with solvent, brake cleaner et., and inspect them closely for cracks. \\+Clean both gerotor sets with solvent, brake cleaner etc. \\ 
 +\\ 
 +**Inspect inner and outer pieces of both gerotor sets closely for cracks (most cracks are going to run vertically)**. \\
 It may be hard to see cracks from a distance or when the gerotors are oily / dirty. \\ It may be hard to see cracks from a distance or when the gerotors are oily / dirty. \\
-The outer return piece below was cracked but not all the way through. Being cracked at all is still a problem (could result in lower oil pressure). \\ +Cracks can happen when debris gets pinned between the inner and outer gerotors. \\ 
-Replace any gerotors with damaged teeth, nicks or cracks. The problem will only get worse. \\+As they spin around and pinch something between them, the offending item tries to bind or lock up the gerotors while the geasrshaft still wants to spin. \\ 
 + 
 +Technically, the solid shear pins on the gearshaft should also be checked for damage if you find a cracked gerotor. \\ 
 +The pins should shear before that much pressure is put on the gerotors. \\ 
 +If aftermarket hardened pins are used instead of OEM pins, they could hold up and not shear which transfers gearshaft energy to the gerotors instead. \\ 
 +This is another example of parts designed to fail before others down line do. \\ 
 + 
 +(L - below) The outer return piece below was cracked but not all the way through. Being cracked at all is still a problem (could result in lower oil pressure). \\ 
 +Replace any gerotors with damaged teeth, nicks or cracks. \\ 
 +The problem will only get worse (gerotor will break into pieces) and oil pressure will be lower until the gerotor breaks. \\ 
 +(R - below) The inner feed gerotor broke into 4 separate pieces starting from the slot in the gerotor where the gearshaft pin catches it. \\
  
-{{:techtalk:ih:oil:1983l-1985_outer_gerotor-_cracked_by_attaxic.jpg?direct&300|}} ((photo by Attaxic of the XLFORUM http://xlforum.net/forums/showthread.php?t=2078758&page=4)) \\+{{:techtalk:ih:oil:1983l-1985_outer_gerotor-_cracked_by_attaxic.jpg?direct&300|}} ((photo by Attaxic of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/201663-1983-ironhead-oil-not-returning/page4?t=2078758&page=4)) {{:techtalk:ih:oil:1977-1985_inner_feed_gerotor_broken_by_freewheeler.jpg?direct&300|}} ((photo by Freewheeler of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/174337-homebrew-ironhead-sheared-oil-pump-pin?threadid=1869407)) \\
 \\ \\
  
 **Check inner to outer gerotor clearance on each gerotor set**. \\ **Check inner to outer gerotor clearance on each gerotor set**. \\
 Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\ Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\
 +This clearance has a direct relationship to oil pump flow and oil pressure. \\
 +The wider the clearance the more the gerotors lose their ability to hold enough pressure to the outlet cavity. \\
 +They also the ability to transfer oil from the feed cavity back to the inlet cavity and recirculate oil within the oil pump. \\
 +
   * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set.    * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set. 
  
 {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\
 +
 \\ \\
  
-  * Measure the height of each inner and outer gerotor set. \\ Each inner and outer piece (feed side) should be the same height, each inner and outer (return side) should be the same height. \\ Replace gerotors as a set respectively if the inner and outer pieces are not the same height. \\ A micrometer will reveal tighter measurements rather than the caliper used below. \\ However, there are so many small variances in these pumps that less than .001" increments isn't going to be the hill to trash your pump on. \\ +  * **Measure the height of each inner and outer gerotor set**. \\ Each inner and outer piece (feed side) should be the same height, each inner and outer (return side) should be the same height. \\ Replace gerotors as a set respectively if the inner and outer pieces are not the same height. \\ A micrometer will reveal tighter measurements rather than the caliper used below. \\ However, there are so many small variances in these pumps that less than .001" increments isn't going to be the hill to trash your pump on. \\ 
  
 {{:techtalk:ih:oil:77-85_gerotor-_measuring_feed_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_gerotor-_measuring_return_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ {{:techtalk:ih:oil:77-85_gerotor-_measuring_feed_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_gerotor-_measuring_return_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\
 +
 ===== Inspect the Seals and O-rings ===== ===== Inspect the Seals and O-rings =====
 It's never a bad idea to replace seals and O-rings every time you go into the oil pump. \\ It's never a bad idea to replace seals and O-rings every time you go into the oil pump. \\
Line 214: Line 191:
  
 {{:techtalk:ih:oil:1977-1985_oil_check_valve_assembly_pic_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:12036_and_12036a_outer_plate_seals.jpg?direct&300|}} ((photo by Hippysmack)) \\ {{:techtalk:ih:oil:1977-1985_oil_check_valve_assembly_pic_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:12036_and_12036a_outer_plate_seals.jpg?direct&300|}} ((photo by Hippysmack)) \\
 +
 ===== Inspect the oil check valve ===== ===== Inspect the oil check valve =====
 [[techtalk:ih:oil01#oil_pump_check_valve|Click Here]] to read more about the oil pump check valve in the Sportsterpedia. \\ [[techtalk:ih:oil01#oil_pump_check_valve|Click Here]] to read more about the oil pump check valve in the Sportsterpedia. \\
  
     *  Make sure it's not clogged and the internal spring closes the cup / disc properly. \\ The spring loaded cup inside the valve should be free to move and should return to it's closed, seated position. \\ It the check valve is damaged in any way, the complete valve assembly should be replaced. \\ There are no replaceable parts to it.     *  Make sure it's not clogged and the internal spring closes the cup / disc properly. \\ The spring loaded cup inside the valve should be free to move and should return to it's closed, seated position. \\ It the check valve is damaged in any way, the complete valve assembly should be replaced. \\ There are no replaceable parts to it.
 +    * Loose metal particles can get stuck between the disc and the valve body keeping the disc from closing. \\ If you find metal debris in the check valve, there may also be metal that made it's way past the check into the motor.  
  
-{{:techtalk:ih:oil:77-85_oil_check_valve_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_oil_check_valve_drawing_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ +(R) below, the check valve was stuck open with metal debris. \\
-===== Inspect the spring washer =====+
  
 +{{:techtalk:ih:oil:77-85_oil_check_valve_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_oil_check_valve_drawing_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:1977-1985_oil_pump_check_valve_by_screwloose.jpg?direct&300|}} ((photo by Screwloose of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/184257-oil-pump-porn?t=1979566)) \\
 +
 +===== Inspect the spring washer =====
 The spring resides between the separator plates (between the feed and scavenge gerotors) and is supposed to keep pressure against both plates. \\ The spring resides between the separator plates (between the feed and scavenge gerotors) and is supposed to keep pressure against both plates. \\
 The inner plate stops at the housing bore "shelf" and doesn't push against the return gerotors. \\ The inner plate stops at the housing bore "shelf" and doesn't push against the return gerotors. \\

Trace: