Out of time/ratchet bind after fixing cylinder endshake

[schneiderguy]

I have a 28-3 that appears to have very few rounds through it. But, it has about .005" endshake. I guess it came that way from the factory.

I decided to fix the endshake with two .002" endshake bearings. I installed them without any problems, and the cylinder rotates freely, and endshake is now unnoticeable.

However, now one cylinder fails to completely lock up about half of the time, and the weight to cock the hammer increases about halfway through the stroke.

I'm thinking that this is a hand-ratchet bind caused by moving the cylinder back. If I recall correctly, I read on here that given enough cycles a hand-ratchet bind will fix itself. But I'm concerned that the timing issue will only get worse. What would be the best action to take in this situation?

 

[PPCSHOOTER]

YES THAT COULD BE THE CAUSE., BUUUUUUUUT. THERE ARE 2 KINDS OF ENDSHAKE. ENDSHAKE YOKE AND ENDSHAKE CYLINDER. THE BEARING ON THE YOKE FACE INSIDE THE CYLINDER,FIX ENDSHAKE CYLINDER. BEARINGS ON THE YOKE STUD WHERE IT FITS INTO THE FRAME, FIX ENDSHAKE YOKE.

TAKE 1 BEARING OUT AND SEE IT IT CLEARS UP YOUR PROBLEM. JP

 

[Bat Guano]

I have done the bearing thing (on a M18) successfully. I have Kuhnhausen's book plus some bootlegged armorer's notes from the S&W armorer's school (I never got there on my own). Every once in a while I find myself in over my head in that area--everything is connected to everything else!

A couple of times I have just boxed the gun up and sent it in to S&W. They may be slow, but they "know stuff" most of us mortals do not.

 

[schneiderguy]

YES THAT COULD BE THE CAUSE., BUUUUUUUUT. THERE ARE 2 KINDS OF ENDSHAKE. ENDSHAKE YOKE AND ENDSHAKE CYLINDER. THE BEARING ON THE YOKE FACE INSIDE THE CYLINDER,FIX ENDSHAKE CYLINDER. BEARINGS ON THE YOKE STUD WHERE IT FITS INTO THE FRAME, FIX ENDSHAKE YOKE.

TAKE 1 BEARING OUT AND SEE IT IT CLEARS UP YOUR PROBLEM. JP

I tried removing one bearing, and it still binds but not quite as badly. I don't detect any movement of the yoke in the frame so I think it is cylinder endshake.

I have done the bearing thing (on a M18) successfully. I have Kuhnhausen's book plus some bootlegged armorer's notes from the S&W armorer's school (I never got there on my own). Every once in a while I find myself in over my head in that area--everything is connected to everything else!

A couple of times I have just boxed the gun up and sent it in to S&W. They may be slow, but they "know stuff" most of us mortals do not.

Yeah, I might have to just send it in, although I hear it'll be at least half of a year before I see it again.

 

[tomcatt51]

I tried removing one bearing, and it still binds but not quite as badly.

How much endshake do you have now with only one bearing? Is it still "unnoticeable"?

 

[mmncw]

Did you square the face of the yoke before you put the shims in? With .005" end shake, if the yoke and cylinder are not flat and parallel, it would take less than .005" to cause a bind. This is a bit of an oversimplification, but picture it like this: (.....( It has 5 spaces of clearance, but 5 spacers of flat spacer won't fit in between because of the curve.

 

[schneiderguy]

How much endshake do you have now with only one bearing? Is it still "unnoticeable"?

About .003".

Did you square the face of the yoke before you put the shims in? With .005" end shake, if the yoke and cylinder are not flat and parallel, it would take less than .005" to cause a bind. This is a bit of an oversimplification, but picture it like this: (.....( It has 5 spaces of clearance, but 5 spacers of flat spacer won't fit in between because of the curve.

I did not. The cylinder spins freely on its own even with two endshake bearings in, it's just when cocking the hammer it feels like it is binding.

Thanks for all of the help so far, everyone.

 

[tomcatt51]

Two things:

Does the extractor rod run true? Open the cylinder, spin it, and watch the end of the extractor rod.

With the cylinder closed pull the trigger back just enough to get the cylinder stop to drop. Hold it in that position. Does the cylinder spin pretty freely or does it bind up?

 

[Big Cholla]

And be a little wary about taking all of that end shake out while the handgun is cold. For proper functioning of the cylinder cycle a little movement is needed to allow for thermal expansion of the cylinder after having been fired several times. The cylinder will expand much more rapidly than the frame . ........... Big Cholla

 

[ricklee4570]

I am having the exact same issue after putting some endshake bearings in my model 29-3. Every 5th or 6th trigger pull (double action) binds a little. Enough to where a smooth trigger stroke is impossible. When cocking by hand you can feel the resistance come and go. Curious whatever happened with the OP situation? Did it smooth out on its own after some time?

 

[Hapworth]

Big Cholla makes an excellent point about thermal expansion; this is why Kuhnhausen recommends dialing in approximately .001" of endshake when correcting.

ricklee4570: Are you certain you measured endshake correctly before shimming? Sounds like you might've reduced headspace out of spec and are binding as a result.

Alternately, did you scrupulously clean inside the cylinder before inserting the shims, and did you lube the shims? Failure to can cause binding as well...

 

[WR Moore]

Did you check the yoke alignment? The issue of ejector rod bind is very possible, either bend rod or bad machining on the end (chamfer not centered). There also might be a slight uneven part of the headspace button on the ratchet.

The cylinder bore where the yoke rides should have been thoroughly cleaned prior to putting the shims in. Cleaning under the ejector star wouldn't hurt either.

 

[Hapworth]

ricklee4570, had another thought: check your blast plate for burrs; even very minor ones can be an issue after correcting endshake. I had a K with a little endshake that cycled fine until correction, then the burrs caused binding and needed to be smoothed.