Loose Arbor - Uberti Walker

[jdixon]

I have owned a Uberti Walker for several years. Fired several hundred rounds thru it. Usually load it up around 55 grains for target shooting. I occassionally hunt whitetails with it (yeah, it works just fine!) and want the heavier charge so that is what I practice with. This fall, accuracy suddenly went to pieces. This gun had been a tack driver, now it was all over the place. Examination found that the arbor, or what some may call the cylinder pin, had become loose. The arbor is only held fast to the body of the frame of the gun by what appears to be a peened over pin that pushed into a hole drilled in the back of the cylinder frame area. The rear of the pin can be seen in the slot that the hammer falls into. I have tried re-peening this pin, which tightens the arbor up for one shot, then it is loose again. Does anyone have any ideas on what can be done to fix this loose arbor problem?

 

about the only permanent fix would be to have it soldered or brazed in place,
Solder would be better as less heat is needed.
But brazing is stronger

 

[Dphar]

Several choices.
Buy a different Walker and hope its put together better.
Have the current piece removed and a better one, that fits the threads tighter made then staked in properly.
Might try some of the penetrating loc tite. The highest strength stuff they make. Might work.

Dan

 

[Dphar]

Brazing or high temp silver solder will lock the pin in place but the frame may be warped in the process. This brings it back to buying another revolver.
Dan

 

[jaxenro]

The loc tite is cheap enough you aren't out anything to try it

 

[yakimaman]

Why not try contactin VTI or Taylor & Co to see if it can be repaired.

 

[rodwha]

When brazing copper with parts such as neoprene washers or such, we use a paste that helps keep the area from heating up too badly. Maybe this would help enough so that the stronger fix can be made?

 

[M. De Land]

I would just clean the peened area back a bit with a file , back out the threaded arbor, degrease it and the frame hole and use one of the red thread lockers like Loc-tite or Permatex. They both expand and wick out before setting up and will lock the arbor up very tightly.It also takes something like 350 degrees F. to let go.
Just lined my first barrel using red Permatex and it seems to hold fine with no threads involved.
I usually sweat them in with High Force 44 solder but wanted to try a glue in as that seems to be the current thing to do even when relining for match use.
I think I still prefer the sweat in method although it is a bunch more work because the joints seem to be less visible. Mike D.

 

[jaxenro]

My other thought would be the epoxy they use for gluing barrel liners in with

 

[jdixon]

Well there is something I did not know, that the arbor is threaded into the frame body. I could not find a parts diagram of a Walker that showed just how those two pieces were mated together. I thought it was just a pressure fit with the roll pin peened over to hold it. If I can back that arbor out, the Prematex is a great idea. Also thought milling in a tapped hole into the rear of of the arbor and securing the two parts together with small #6 or #8 screw. A lot more work though.

 

[No Deer]

Exploded view, parts list for the
walker
http://www.gunpartscorp.com/Manufa...ers-42389/1847ColtWalker-37936.htm?results=40

 

[M. De Land]

Notice the lock pin in the Walker arbor thread. This will need removed and probably drilled out before you can back it off the threads. I did not know of this although it will show up in your gun, if present, when one files down the peen at the back.
I need to point out that I have not personally removed and arbor and used loc-tite on one just that I can see no reason it would not work and would not hesitate to employ it on one of my guns had a loose arbor come up.
Love to learn new stuff. Mike D.

 

[slippery50]

You might want to consider using "MarineTex". Once it cures, it will never loosen up again.

 

[Zonie]

You folks who want to try to fix your loose cylinder arbor using one of the thread locking compounds, epoxies, glue or whatever need to keep in mind that the loosening happened to steel or brass parts.

A steel cylinder arbor that loosened in a steel frame was most likely repeatedly subjected to excess stress. Probably by using max powder loads.
Even if this isn't true, something exerted a lot of stress on the parts.

Even the weaker brass castings are harder and stronger than the best plastic fixes being considered and there is no contest if one is comparing steel with these fixes.

I'm not saying that one of these fixes shouldn't be tried but don't be surprised when it fails.

(Course I know you guys are all too honest to make a poor fix and then sell the gun to some unsuspecting person. Right? :hmm: )

 

[M. De Land]

Good point Zonie! Should be able to tell if the arbor threads have pulled when you get it out.The frame is cased and should be the harder of the two. If the arbor threads are stretched than a new arbor can easily be made of tool steel, 0-1 or A-2 and it will stay put as they both have tremendous tensile numbers.

 

I wonder if it might be better to helicoil the arbor pin. But, I'm not sure what to do about the "Cylinder Lock Pin."

 

[jdixon]

Thanks to everyone who gave me suggestions on fixing the Walker. I have done a repair on it, shot it and it appears to be functioning very well. This repair is fairly easy to do, here is a short description of what was done.
For this description, I will use the part #’s that appear on this exploded view diagram of the Walker found here - http://www.gunpartscorp.com/Manufacturers/Uberti-33543/Revol... This is the best such diagram I have seen on the Walker, thanks to No Deer for sending along this link!
The arbor, or base pin #21, is screwed into the revolver’s frame #1, the rear of it can be seen in the hammer channel at the rear of the frame. The arbor is held fast in this position by means of another pin called a cylinder lock pin #28. This pin is inserted into a hole drilled into the threads of both the arbor and the frame. This pin is peened into position. In the case with this revolver, it was this pin that had worked itself loose, probably from several hundred magnum rounds being run thru it, and it was allowing the arbor to move slightly.
To repair this issue one must first remove the cylinder lock pin #28. The diameter of this pin was .117”. Use a drill bit smaller than this, I used a #35 drill bit, and carefully drill into the end of the cylinder lock pin. Once about ¼ of the pin had been drilled out the pin was easily removed. At this point the base pin #21, was easily removed from the frame by unscrewing it.
I cleaned and de-greased the threads with acetone, applied Lock-tite to the threads and screwed the base pin into the frame until it was seated back in it’s original position. At this point it is important to partially re-assemble the revolver by putting the barrel assembly #3 back onto the frame and inserting the wedge assembly #4. Doing this while the arbor is still loose ensures that the barrel and frame will line back up on the barrel pins #23 at the front of the frame. If you fail to do this, it is possible to set the base pin #21 in the wrong position and it will be .almost impossible to re-assemble the gun after completing the repair and tightening up that part.
Now with the gun partially assembled, barrel and wedge in place, cylinder still out, you will need to re-insert a new pin to replace the old cylinder lock pin #28. In my case I did not have any .117” mild steel stock around the shop, but I did have plenty of .125” stuff. I carefully drilled this hole out to .125”, then cut a small piece of the .125” round steel stock to a length slightly longer than the depth of the hole then filed a small taper on the forward end of this pin. The pin is inserted into the hole and tapped in as far as possible. I then used a center punch to drive the pin home further and bulge it slightly. The end of the pin is filed flush, a #2 pillar file was perfect for this. Finally, using a very small cold chisel, the rear of the new cylinder lock pin is stuck, peening the pin and the frame together. Two peens across this area was all that was needed.
At this point the gun was tight, the wobble in the arbor was gone. I let the Walker sit for two days allowing time for the Lock-tite to fully cure. I took it out and ran three cylinders thru it with 50 grains of 3F Swiss and a .457 ball. It is now again holding a 2” group at 25 yrds.
In researching this problem last month I found several people who have had the same problem with a Urberti Walker. In one case someone mentioned that they had actually retired the gun and bought another. Hopefully what I described here may be helpful to someone else in the future and keep one or more of this fun to shoot revolvers from going to the bone yard.
P.S. to Zonie ”“ I do not plan on selling this gun, it’s too much fun to shoot and hunt with!

 

[M. De Land]

So did the arbor threads appear stretched out and loose in the frame when withdrawn?
I would sure like to hear back from you after putting a few hundred rounds through the gun to find out if the loc-tite holds up.
I can't really see where it can go anywhere being hardened up and captive in the threads. Mike D.