• Torque wrenches come with a variety of drive point sizes. Of course, so do sockets. Unless you have a full shop of tools, it can be cost effective to use adapters to give you the flexibility in using the same sockets with different drive wrenches.
• It's also important at times to be able to get to certain spots with smaller O.D. wrenches with the help from adapters as a (1/4” drive) 1/2“ socket will probably be a smaller outside diameter than 3/8” or 1/2“ drive in the same bolt size.
• Sometimes, it just all depends on what you have on hand and, if you can adapt to it, that saves you money.
• In addition certain drive bits (hex / torx etc.), within a kit of them, will have different drive requirements (usually 1/4” and 3/8“ drive internal squares).
• But, true tool nuts will want to have them all and still need more.
• You can also 2 adapters back to back to go from 1/2” to 3/8“ and then from 3/8” to a 1/4“ drive socket. There are other combinations as well.
• If you plan on using a torque wrench, below are some basic size adapters that you'll probably want on hand. So, go ahead and buy them just to have them. You'll appreciate them all eventually…. and probably want more too.

When buying a torque wrench, these are some suggested adapters to have on hand or buy with it:

• A 1/4” drive torque wrench may be required for the lower torque bolts (primary, gearcase, derby covers, etc.) which you can buy hex (allen) and star sockets for. However, some are 1/4“ and others are 3/8” drive socket ends. So, you'll need a 1/4“ to 3/8” drive adapter to be able to swap back and forth with these sockets and still use the torque wrench to tighten them properly.
• A 3/8“ drive torque wrench (in some instances) may be useful for both 1/4” and 1/2“ drive sockets so you'll need an adapter up and one down for versatility.
• A 1/2” drive torque wrench will probably be too strong to use 1/4“ sockets but you'll definitely want to get a 3/8” adapter in case you need to swap back and forth with 1/2“ and 3/8” drive sockets.
• A 3/4“ drive torque wrench is usually only used in high torque applications and you should only need a 1/2” drive adapter in it's use.

A swivel (or universal joint) is a great little tool for getting into areas where a straight run at a nut / bolt is hindered by obstacles near it (whether by the frame, wheels etc.).

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• But, for the use with a torque wrench, a swivel can be detrimental to achieving even torque. Whether that is a concern to you or your project, you'll have to make that decision. This is just an informative on the subject.
• With the entire purpose of using a torque wrench being to evenly distribute clamping force throughout the clamped piece and the purpose of a swivel is to allow you get to angled areas of your work piece, these two tools seem to cancel each other (in theory).
• How much the swivel will change the actual torque on a fastener depends entirely on the angle at which it is used, if the swivel is near the wrench or near the bolt and etc. Any angle different than 90° from the wrench will shorten the distance from the bolt to the wrench. This shorter distance will decrease the amount of actual torque applied the bolt.
• You wouldn't think that the length of a socket extension between the swivel and the torque wrench would affect actual torque. But the truth is that the longer the extension you use, the more angle you can put on the swivel which does change actual torque at the fastener.
• A swivel adapter will transmit different amounts of torque and rotation depending on where the two pins are relative to the angle. You can see this for yourself by sticking two extensions into the adapter, bending it about 70 degrees, and slowly rotating the two extensions. With a small angle the error is not too large but as the angle increases the errors increase. ⁵⁾
• With these conditions in mind, swivels have been used with torque wrenches for a very long time. Of course, results will vary and some will say the amount of change in actual torque value at the fastener will be negligible. This is ultimately left up to the end user to decide what is best for them.

Typical application for tightening rocker bolts on an IH engine 'in frame' 6)		This is the toughest one to do, the front right stud on the rear cylinder. 7)

• These are usually considered methods to extend the length of the wrench (in a linear plane) from the drive center to get into confined spaces that the wrench head (or socket) is too big or awkward for. However, for whatever or how you are extending the end of the torque wrench, you'll need to re-calculate the torque setting on the wrench. Extending the end of the wrench (whether with a crows foot, dog bone or other) will add extra leverage (torque) on the nut / bolt so you'll have to lower the setting on the wrench to compensate.
• Torque is measured at the socket axis. It does not depend on the length of the wrench handle. That only affects the amount of pressure you have to exert to achieve a particular torque.
• The extension is measured from center axis ⁸⁾ to the drive (shaft) axis of the torque wrench.
• The calculation is the same for all types of torque wrenches (whether clicker or beam type). The torque wrench tells you how hard you are pulling at the handle when you back out the ft/lbs, the formula tells you how much torque is on the fastener when you make the wrench show that many ft/lbs. ⁹⁾
• You can search online calculators to find the value to set your torque wrench to achieve actual torque at the fastener.
• Or, this formula ¹⁰⁾ will allow you to achieve (actual) torque on your fastener. M1 = M2 x L1 / L2
  Where:
  • M1 is the torque setting of the wrench
  • M2 is the actual torque applied to the nut
  • L1 is the normal length of the wrench (square drive shank center point to pull handle center point).
  • L2 is the extended length of the wrench (square drive shank center point on wrench to center point of bolt / nut).

Homemade Wrench Extension for in-frame applications 11)

1/2 torque wrench (L) inside a pull handle wrench (minus the handle). 3/4“ drive torque wrench (R) with 1/2” adapter and a socket to fit the square shank of the 1/2“ wrench. You can torque to about 140 foot pounds with this contraption but you have to keep straight alignment with the 2 wrenches or actual torque on the nut will change. This is Not a proper tool setup but it will work with lower torque values. 12)
13)
This application is used to adapt a 1/2” drive socket for use with a 3/4“ drive torque wrench. Really! 14)