Cylinder gap and yoke in 686-3

[teemumm]

When I was cleaning my 686-3 I noticed that there might be a little bit of end-shake in the cylinder. So I took a gauge and measured it. With cylinder pushed front I measured about 0.006" between cylinder and barrel and cylinder pushed rear 0.010". So this would mean end-shake is 0.004". I have understood that this is maybe little bit too much and maybe should be corrected.

However when I inspected the gun more, I noticed that this end-shake was not caused by play between the cylinder and the yoke, but between the frame and the yoke. Is this normal that there is this kind of wear in S&W or is it possible that yoke has bent a little bit?

I have heard that cylinder end-shake can be corrected by putting some shims between cylinder and yoke, but in my case this probably won't help? There is also some shims available for yoke, but are they for this kind of cases? Is it enough if I just add that small shim to yoke, or should I start to look for a smith who knows revolvers to fix this?

 

[500 Magnum Nut]

YOKE ENDPLAY

To adjust the yoke screw:
Use a file and lightly file the bottom of the screw until the cylinder swings without a lot of resistance. I like them with a bit of drag, but not binding.

If you tried the screws, then the yoke stud is too long (or the slot is worn) and needs to be adjusted.

You need to flatten the button of the yoke. Find a 1 inch round bar (Babbitt bar would be nice) and place the yoke body on it. Using a hammer lightly tap the button (on the corner) to make it flatter, (peen only 1/2 way around) then if you need to, file out the slot where the screw fits so it can be tightened up. Only file what you have to, or it will be loose again. You're trying to narrow the slot opening where the screw goes (Look for the screw rub mark). Your not trying to move the whole 9 yards, just deform the slot.
Tap lightly, check the fit often.

 

[teemumm]

I think with 686-3 you don't have to adjust the yoke screw. The screw has spring-loaded tip. I think this is the "new yoke retention system" that is mentioned as difference between 686-2 and 686-3.

 

[500 Magnum Nut]

Yes, you are correct. It has the new style yoke screw, try another screw. Perhaps the spring is weak or the plunger is loose fitting in the screw head.

 

[Armen]

End play shims

I've used shims available from Ron Power (Power Custom) very successfully to eliminate end play without hammering : )
He offers yoke shims as well as cylinder shims.
-Armen

 

[teemumm]

Is it enough if I just order shims and install them, or is there need also do some other smithing? If I would have to use file, I think I'll start to look for a smith instead of trying to fix this myself.

I think it is not enough to add yoke shim or is it? If I add yoke shim, then there will be play between shaft and cylinder and I should also add shim there. Right?

 

[Armen]

Shims-R-Us

Shim the yoke end play first, then the cylinder endplay. If you have any fine oilstones, you can dress the end of the yoke where the shim rides up against.