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| - | techtalk:ref:engmech01a [2024/01/14 16:27] – hippysmack |
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| + | techtalk:ref:engmech01a [2024/01/14 16:45] (current) – hippysmack |
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| * You can generally purchase these at most machinist supply stores online cheaper than you can buy them from motorcycle supply stores 'made for Harleys' | |
| * They do not have to be expensive. They simply have to be the right size and shape for your application. | |
| |**5/ | |
| @@ Line -77,6 +76,6 @@ | |
| * **Choosing the right tap** | |
| * A bottoming tap only has a very short taper on the end to allow it to get inside the hole. It will immediately cut the threads before it bottoms out into the flywheel. ((Whitewalls of the XLFORUM | |
| * A tapered (not to be confused with tapered thread) or plug style tap has a longer tapered end. The tapered end does not cut any threads and it will bottom out against the flywheel before the threads are finished cutting. It is designed to help you center up in the hole for tapping new threads. If you continue turning from that point, you risk back pressure on the tap which could crack the case. If you aren't planning on doing this again, you could cut off the taper ((iNSaNeSHaNe of the XLFORUM | |
| * **Choosing the right die** | |
| * You can use a standard round or a hex die. Either will do the job and possibly be held in your palm for use. But, if your threads are bad enough to need repairing this way, you probably need to buy the wrench for it. | |
| @@ Line -87,5 +86,5 @@ | |
| * **Thick lube or grease** is needed to catch and hold the shavings and keep them from flinging through the engine case. You will need to clean the threads after your done repairing them. Using compressed air from the engine out through the hole will not work while using lube since the shavings will cling to it and not be blown out of the hole. | |
| * **Optional Items**: | |
| * **Panty Hose**: Stuff a small piece (3" - 4" long) of panty hose into the hole prior to any work (between the flywheel and the case while allowing a small amount to be gotten to later with a pick). Make sure the material is not in the way of your work. You wouldn' | |
| ==== Thread Repair ==== | |
| @@ Line -137,19 +136,16 @@ | |
| ===== Using an Aftermarket Drain Plug or Bolt with Longer Threads ===== | |
| The factory timing hole plug can be up to app. 1/2 the length of the threads in the case on Evo engines and the entire length minus a couple threads on IHs. If you have stripped threads in the front half of the case, chances are the threads in the rear half of the case hole are still good. | |
| * Aftermarket 'drain plugs' can be purchased at auto parts stores and can be a suitable replacement for the factory plug. | |
| * You'll need to check the O.D. of the head and make sure it will seat properly to the machined mating surface in the case. If it's too big, you may need to round sand or grind the head diameter slightly with a grinder. ((jordan1200 of the XLFORUM | |
| * While using a bench grinder, mark one flat of the head with a sharpie marker to verify when you've made a complete rotation of the drain plug. This visual helps in allowing you to keep the head the same diameter all the way around. Keep nice even pressure while turning the plug against a medium grit wheel and clean the edges on a wire wheel (with light pressure applied). ((jordan1200 of the XLFORUM | |
| * Some, if not all, aftermarket drain plugs are longer than the stock plug and will catch those last few threads in the rear of the hole. ((IronMick of the XLFORUM | |
| |The head may be larger than the original but it can be ground to fit with a bench grinder. ((photos by Jordan 1200 of the XLFORUM | |
| |{{: | |
| |Measure the heads on the old and new plug, grind the new one if needed. ((photos by Jordan 1200 of the XLFORUM | |
| |{{: | |
| ===== Cutting New Threads for an Oversized Plug ===== | |
| @@ Line -162,21 +158,19 @@ | |
| * **First, clean the work area** so as to not induce outside trash / debris into the case. If there is trash in the threads, you can use a 90° angled pick to scraped them loose and cut a small piece of rag or panty hose to shove thru the middle of hole, pack it in and then turn counterclockwise and outward as in the pics above. Any loose debris within the hole can get shoved into the case with the next steps if not cleaned out first. | |
| * **Debris control**: | |
| * **Compressed air method**: Blow regulated air into the crankcase, adjust the air pressure so there' | |
| * __On IH engines__, connect a regulated air hose to the crankcase breather. ((rivethog of the XLFORUM | |
| * __On frame mount Evo engines__, this is a little more involved. The carburetor needs to come off to get the crankcase breather holes (one in each head). Either plug both of them with a 1/2" bolt, remove the cam cover vent at the oil tank and blow air into that hose. Or plug one of the breather holes and blow air into the other one. | |
| * **Grease method**: Cover the case hole and drill bit with thick lube or grease to catch the chips. Inducing compressed air will not be effective while also using grease since the chips will be stuck in the grease and not blow out. These are aluminum shavings, not steel. The steel moving parts inside the engine should consume any minor amount of aluminum that does get in there. And it will come out with the next fluid changes. ((IronMick of the XLFORUM | |
| * **Cut and stuff a small piece (3" - 4" long) of panty hose into the hole** prior to any work (between the flywheel and the case while allowing a small amount to be gotten to later with a pick). Make sure the material is not in the way of your work. You wouldn' | |
| * **Insert a 1/2" steel expansion plug (freeze plug)** into the hole for more protection and against the panty hose to keep from rolling the panty hose up on the bit and also to help guard against chips into the engine. This will allow the bit to spin against it instead of the nylon. Just make sure to grease the freeze plug also. | |
| * **Lube the drill / reamer bit**, especially in the flutes, with some thick assembly lube or grease. The grease on the bit should also help minimize snagging the material. You could also grease the panty hose but the dry material will probably catch and hold more debris. When the job is complete grab the panty hose with a hook pick and needle nose pliers (so you don't let go of the panty hose) and pull it out while turning it counterclockwise to help remove the chips from the threads. Any foreign material not already caught up in the threads should be stuck to the panty hose. ((Whitewalls of the XLFORUM | |
| ==== This Can Be Done with a Hand Drill or a Reamer ==== | |
| * Either of which needs to run in straight or you'll end up with a leak. | |
| * **The Colony oversized plug** has 11/ | |
| * **Centering up**: In order to get a good seal on the new plug, the hole will have to be drilled or reamed straight with the existing hole center line. You can take your chances, eyeball it and hope for the best. But, it's better to use a 5/8" bushing pressed against the sealing edge of the hole with one hand while drilling / reaming through it with the other to keep the new hole from straying. | |
| * A standard 5/8" bushing has an O.D. of 7/8" (.875" | |
| * This may not be as big of an issue on pre-91 models due to the hole sitting higher up off the gear case. However, the hole sits low enough on 91-03 models that a bushing O.D. larger than the machined recess will cause the hole to be off center as the O.D. will rest on the gear case top and not low enough to center up. So, for these year cases (and prior years for safety), the O.D. of the bushing will need to be turned down (just enough to clear the outside of the case) to roughly match the recess unless you can find a thin walled 5/8" bushing. It's cheaper to take a standard bushing to a machine shop than to have them make one from scratch. | |
| === Drilling the Hole === | |
| @@ Line -198,10 +192,10 @@ | |
| ===== Tapping Threads for a Bigger Plug ===== | |
| * You can re-thread the case hole with a 1/4" NPT pipe tap and change to a regular pipe plug. ((MTD of the XLFORUM | |
| * This '71 XLCH case was tapped for a M20 X 1.5 drain plug. | |
| |{{: | |
| | Aftermarket drain plug on a '71 XLCH ((phot by Whitewalls of the XLFORUM | |
| ===== Installing Thread Inserts ===== | |
