I have an older S&W Model 36 that, I think, needs a new yoke. The extractor binds when the cylinder is in certain positions. I checked the extractor, extractor rod, and center pin and they don't appear bent. Just to make sure, I bought a new center pin and extractor rod and still get the binding. (I could not locate an older-style extractor to try.) I pulled the cylinder off and noticed two flat spots on the yoke. Should I round the flat spots with a grinder or should I replace the yoke with a new one? I called S&W and was told that a new yoke would have to be hand-fitted, if that's the problem, and they'd do a tune-up and give me an estimate, etc. = $$$. Is it too involved for me to hand-fit a new yoke as I don't want to put a lot of money into it? Thanks.

First, you "think" it needs a new yoke.
Gunsmith's First Rule:  NEVER replace or alter anything unless and until you KNOW exactly what's wrong.
Guessing doesn't work.

Chances are, you'll spend money on a new yoke, only to find that wasn't the problem at all.

New yokes DO need careful hand fitting.

Like most revolver parts, yokes are NOT "drop-in" parts like most auto pistol parts.

They aren't extraordinarily difficult to fit IF you have the right tools, AND know EXACTLY how to do it.
Explanations over the Internet won't get it.
This is one of those jobs you get right the FIRST time, and trying to learn while doing, doesn't work.

If you want to do it yourself, be prepared to buy a $30.00 book, some special Swiss files, a special yoke trimming tool, and at least several new yokes.

If you want it done right, send it to S&W.  NO ONE knows more about it then they do, they have all the right parts and tools, and they'll have better prices and turn-around than most anyone.
They'll look at the gun, and very quickly KNOW exactly what's wrong, and how to fix it ASAP.

It'll be cheaper to let the pros at S&W do it.

If your cylinder is simple rubbing on a certain point, your current yoke is probably salvageable. I've done this work in the past.. it's a slow carefull process.


Now I will give my standard, smart ass sounding answer. "If you could do it yourself, you wouldn't be asking these questions."

Quoted: ...Should I round the flat spots with a grinder ...

 No!  Put the grinder down!!

Are you sure this is where it is rubbing?  Is it shiny?

First, I’d try this.  Get yourself some cold blue (Birchwood Casey is fine) and blue all the shiny areas on the crane where it might be rubbing.  Then assemble everything without any oil and cycle it a number of times to create a new shiny area where things are rubbing.

When you positively identify the binding area, very lightly cut it down, preferably with a fine stone.  Barring that, I’d wrap some 400 grit wet and dry paper around a flat piece of metal (a small file would work) and use it.

If you need to go inside the hole in the crane, to my mind a snug fitting drill hand-turned would be the best way to go.  A round Swiss file very, very carefully used would also work.  Wet or dry paper wrapped around a dowel rod would work, but wouldn’t be my first choice.  Thing of it is, you definitely don’t want to enlarge the hole at all, just knock down any high areas.

Then reblue the area you worked on and try it again.  Go slow and try to only remove the absolute minimum amount of metal.

Based on what you’ve said, I’d think this would be a fairly easy fix as long as you go slow.

Incidentally, among other problems, fitting a new crane means you’d probably want to refinish the revolver (note how the front of the crane and the front of the frame were obviously polished together).

Quoted:  No!  Put the grinder down!! Are you sure this is where it is rubbing?  Is it shiny? First, I’d try this.  Get yourself some cold blue (Birchwood Casey is fine) and blue all the shiny areas on the crane where it might be rubbing.  Then assemble everything without any oil and cycle it a number of times to create a new shiny area where things are rubbing. When you positively identify the binding area, very lightly cut it down, preferably with a fine stone.  Barring that, I’d wrap some 400 grit wet and dry paper around a flat piece of metal (a small file would work) and use it. If you need to go inside the hole in the crane, to my mind a snug fitting drill hand-turned would be the best way to go.  A round Swiss file very, very carefully used would also work.  Wet or dry paper wrapped around a dowel rod would work, but wouldn’t be my first choice.  Thing of it is, you definitely don’t want to enlarge the hole at all, just knock down any high areas. Then reblue the area you worked on and try it again.  Go slow and try to only remove the absolute minimum amount of metal. Based on what you’ve said, I’d think this would be a fairly easy fix as long as you go slow. Incidentally, among other problems, fitting a new crane means you’d probably want to refinish the revolver (note how the front of the crane and the front of the frame were obviously polished together).

Thanks!  Excellent idea.