Cylinder Endshake

[cavallino]

I have a 627-5 with excess cylinder endshake and placed a 0.004" shim washer to take up the slack. Everything ran perfectly except after a few minutes of dryfiring and opening and closing the cylinder, the cylinder began to bind in the frame and not spin freely. After removing the cylinder and finding the endshake washer concaved in at the top of the cylinder, a closer inspection revealed what looks like too much material has been removed from the yoke seat at the top of the cylinder during manufacture leaving only a very narrow ledge for the end of the yoke to run. Consequently the yoke is only making contact on the outside edge of the very end and is allowing one edge of the washer to slip past the seat in the cylinder and bind. I have now stretched the yoke instead to cure the endshake but was wondering if anybody has ever encountered this problem before? Does anyone use any other methods of curing endshake on smith and wesson revolvers?

[pskys2]

Sounds like you tried the 2 methods. I used one of those Yoke Reamers and trued mine up, then cut some fine wet/dry sandpaper into rings, punched out a hole in the middle attached it to the reamer and polished the end of the Yoke also. Then took the edge off both inside and out. Added some shims and all works well.

The concave shims, after use, seems normal and there has to be a little bit of endshake for things to run smoothly.

The plus of stretching the Yoke is it won't get lost when you do a thorough cleaning.

[Round_Gun_Shooter]

As PSKYS2 suggests, the yoke needs to have a square face to use the shims. Power sells a tool and recommends it be used.

[bountyhunter]

After removing the cylinder and finding the endshake washer concaved in at the top of the cylinder, a closer inspection revealed what looks like too much material has been removed from the yoke seat at the top of the cylinder during manufacture leaving only a very narrow ledge for the end of the yoke to run. // Does anyone use any other methods of curing endshake on smith and wesson revolvers?

That sounds like normal wear where the end of the yoke tube cuts a groove into the mating surface inside the cylinder.

I don't know why, but the end of the yoke tube seems to be a lot harder (and sharper) and cuts a groove into the cylinder seat.

Before you install a shim, you have to flatten off the inside surface of the cylinder the washer runs against. The reason is that the outside diameter of the washer matches the outside diameter of the yoke tube, but the washer extends farther in towards the center. The washer will not drop into the groove cut by the end of the crane tube.... and that makes the washer get 'concaved" at the end when it tries to force it into the groove in the cylinder.

I made a tool using the shank end of a drill bit with 80# sandpaper attached to smooth the inner surface. As long as the inside face is flat and smooth, the washers will work perfectly.

[sensei]

As PSKYS2 suggests, the yoke needs to have a square face to use the shims. Power sells a tool and recommends it be used.

I was using a 0.004 shim, and my end-shake problems was resolved for a while, at the last ipsc match i had again problems (cilynder touch the barrel), at home after opened my revo the shim was in really bad conditions (concave), now i have used the Reamer for the yoke, because the face wasn't perfectly in square.

Now my question is: can i mount two shims (one 0.002 + one 0.004) ? ... how can i understand if they work fine, or if it is excessive ? (in dry-firing it seems go well, but i am not sure it is a good solution).

Thank you to all Wheelgunners for any information.

Luca

[Patrick Sweeney]

Yes, you can stack washers. Some guns will sulk if you get too many in the stack, even though it starts out fine. (I call it "Washer squash.")

If you need more than three, you should stretch the crane to take up some of the slack.

[Tom E]

The endshake washers work great but only if the bearing surface down in the cylinder is flat. Find the right size drill bit, flatten the end, glue a little piece of sandpaper to it and true it up. Doing it in the kitchen sink so you can drizzle a little water on it while sanding will help keep the sandpaper from loading up. The cyl. alloy/heat treat is kind of "gummy". True up the end of the yoke too. Once the surface is flat you can stack shims forever. The need for this BS process would go away if S&W would make the cyl. harder. just like the stop notch peening. Tom

[pskys2]

+1 with Patrick's notes. The lighter your action job the more critical the endshake becomes.

I also noticed the concave look. You can try putting a .002 under the concave one and it may help. Too tight can cause problems also and not just increasing the pull weight.

[haras]

Where can you buy a rod to put inside the yoke when peening it?

[Round_Gun_Shooter]

Where can you buy a rod to put inside the yoke when peening it?

Brownells

http://www.brownells.com/aspx/NS/store/Pro...ESSON+REVOLVERS

[haras]

OK, I guess you're going to have to draw me a picture. Which tool is it?

2 - BROWNELLS YOKE/CRANE ALIGNMENT TOOLS ?

[pskys2]

OK, I guess you're going to have to draw me a picture. Which tool is it?

2 - BROWNELLS YOKE/CRANE ALIGNMENT TOOLS ?

The tool 080-640-000 Crane Stretcher, crushes the tube to stretch it.

The tool is 080-627-000 Yoke/Crane Reamer, removes and smooths the inside of the Crane. I know of nothing that keeps the crane from being crushed inward, as that is what stretches it.

[Tom E]

http://www.brownells.com/aspx/NS/store/Pro...+ALIGNMENT+TOOL

This is what is supposed to go inside the yoke while using the stretcher. I suspect the shank of a 5/16 drill bit would do. Peening the yoke will stretch it but has a chance of putting a slight bend in it in the process. Tom