Difficulty opening cylinder - Model 66-1

[just plain joe]

I purchased a S & W Model 66-1. It has been fired very little.

Upon receipt, I cleaned it and checked all screws for tightness. Upon tightening the screw that secures the yoke/cylinder assembly, it became difficult to swing the cylinder out as well as push it back into place. When I loosen this screw, the cylinder swings freely.

If anyone else has experienced this, please let me know how you resolved this problem.

TIA.

JPJ

 

[Protocall_Design]

Trade places with the yoke screw and the one behind it. One screw is fitted, one is not. They both look the same.

 

[just plain joe]

Thanks, ToolGuy. Did as you suggested, but no luck.

 

[Marine Corps Air]

I am not sure whether or not this response will be helpful, but here goes. I believe that is the "crane screw" and may also be called the "yoke screw" If I am wrong, hang tough - I'll be corrected. It is a fitted screw specifically for that position in your Model 66-1 (and all other Smith & Wesson revolvers for that matter). If you completely remove it, you can pull the cylinder assembly towards the muzzle for a better cleaning solution. I don't.

Tension on that screw also controls the tension on the yoke opening & closing, just as you have described. There have been several posts on this subject in the past:

Yoke Screw Too Tight?

I believe that if you turn the screw counter-clockwise very slightly you'll solve your problem. The screw is presently just too tight.

Bill

 

[Protocall_Design]

If the screws aren't in tight, they will loosen from shooting and fall out. One screw needs to be fitted for that spot. Sometimes the end is too long, sometimes too big diameter. Sometimes you fit the crane. It's a pretty simple job, but best done by someone who knows the ropes.

 

[just plain joe]

Bill:

Thanks for the info and the link to prior posts. You are correct, loosening the screw does in fact facilitate easier opening and closing of the cylinder. My only concern here lies in the possibility of the screw backing out and being lost during a firing session.

 

[Jimmyjones]

The correct way is to fit the screw, it should be tight.

Remove it, run the inside surface across a file, re-install, test the opening/closing. If it's still tight remove it strop it again, repeat till it's smooth opening.

Don't remove too much metal each time, as you can't put it back. That was how it was done before they went with the spring/ plunger screw.

 

[Marine Corps Air]

I'll ratchet this up a notch. I am not sure what the torque specs are for that screw, but I was only thinking a very, very slight counter-clockwise turn. One suggestion that might work is to turn the screw very slowly counter-clockwise until the yoke opens and closes smoothly. Then test that position to confirm that there is a low risk that the screw will back out during firing or carry. That is, the screw should be tight enough to 1) allow the yoke to open and close smoothly, and 2) be tight enough to not back out. I admit, this is a trial-and-error method, but it should work without investing a lot of time.

All of the posts that I have read in the past in all forums recommend not using Loctite.

Pictures of the screw, especially the end will help all of us. I sure hope that the previous owner (if there was one) did not grind that screw tip (end).

In this post (Post #4) Gun 4 Fun suggests contacting Brownell's. That is also an option as well as Numrich, or even better, Smith & Wesson Customer Service.

Yoke screw question NOW WITH PICTURES

If either forum members chief38 or Alk8944 respond to this post, you'll be "in tall cotton!!" (old Georgia expression. Young people today have no clue what this means.)

Bill

 

[ken158]

Does not make sense that a 66-1 has a Yoke screw that is not fitted properly. Somebody has replaced the original screw with a different one and did not know how to fit it. A Yoke screw is different from a round head sideplate screw. Oh yeah - Smith's have Yokes and Colts have cranes...

 

[Arquebus357]

You have 2 round head screws and one flat head screw. One of the round heads should have been fitted at the factory. The flat head screw is flat because it's the one that is covered by the grip.

 

[FlyFish]

I had the exact same problem with a Model 32. Backing the yoke screw out in effect makes it a bit "shorter", so I figured it had to be too long. I shortened the screw the tiniest amount with a few strokes on a fine stone, reinstalled and tested. Did that a few times and it solved the problem. Been fine ever since.

 

[armorer951]

All the older, non spring loaded crowned sideplate screws are the same. The yoke screw is fit to the button of the yoke during assembly. Fitting consists of filing the front side of the yoke button where it interfaces with the unthreaded pilot at the end of the screw. The screw is not shortened, filed, or modified.

If you look carefully at the back side of the yoke button with a magnifier, you will see the contact mark from the unthreaded pilot at the end of the yoke screw. The button should show a contact mark from the screw pilot during the entire arch of the yoke's "opening/closing" phase. This contact line is normal and actually desired. A very small amount of material can be removed from any point of this obvious contact or bearing surface line if the motion of the yoke is restricted by excessive contact. The yoke should open and close smoothly, but the button should remain in contact with the screw pilot.

Use caution when removing material from the button as this properly fit interface controls (eliminates) any gauge between the button and the yoke screw, and thus prevents what is called "end shake on yoke." A little bit of lubricant on the bearing surface may eliminate the problem without any intervention at all.

 

[just plain joe]

I wanted to say "Thanks" to each of you that took time to reply to my question. After much thought I felt it best to return the Model 66 to S & W.

The responses were very informative and because of them I now know what I didn't know. Hopefully they may be of benefit to someone else who may has a similar problem.

Best to all.

JPJ