End shake bearing question....

[toad67]

Have a couple of revo's that could use a little front end work. Currently have some items in my basket at Midway, including some end shake bearings from Power Custom, in .002". Midway also has yoke bearings from Power Custom, in .002", that are "designed to work with the end shake bearings".
I looked on the P/C website, and sure enough, they have both. So what's the difference between an end shake bearing/shim and a yoke bearing/shim? TIA.

 

[toad67]

After thinking about it, after posting, I'm guessing that one is for shimming the yoke/crane, and the other is for the cylinder only. What's the best way for determining which one to shim? I use feeler gauges between the cylinder and the throat, with the cylinder to the rear and go from there.

 

[Shotguncoach]

Ooohh....I know this one! Pick me! Pick me!

Yoke shims are used to correct excess clearance between the yoke flange and the frame. There should be "firm but light" contact between flange and the frame.

The yoke shim will move the yoke (and cylinder) towards the muzzle, which has the possibility of creating excess headspace or rear gauge. The cylinder shim recovers that space by moving the cylinder away from the muzzle, bringing the rear gauge back into spec, which is .060" to .068".

Cylinder shims are also used by themselves to correct excess endplay if the yoke clearances are correct. The two should be checked together. Correct the yoke clearance first if needed.

Edit: I had to find one of my own pictures to mark up so that I didn't stick my foot into any copyright issues.

 

[retired2006]

You might want to check these guys, they are the shim experts !
S&W K L N Revolver Shim Kits

 

[toad67]

How does one test to see if the yoke needs shimmed, or if the yoke screw is messed up?

 

[armorer951]

Some additional information about the yoke contained in some recent threads here on the forum.


https://smith-wessonforum.com/s-w-smithing/716199-fitting-yoke-screw.html?highlight=yoke+fitting



BTW: If the yoke is loose with the yoke screw installed, you might be able to remedy the excess "front to back" gauge on the yoke by switching the crowned sideplate screws. Your other sideplate screw located above the trigger may have a slightly larger pilot.



Carter