Worn wheel bearings

[lionelsoni]

I am agonizing over how to rejuvenate the wheel bearings on my Lionel 253 locomotive. The gear teeth still engage and it still runs, but it is rough. The axle diameter measures .180 inch and the bearings will not quite admit a 3/16-inch drill (.1875).

I have a donor motor with better bearings, but I see no easy way to get them out for the transplant. I have also considered swapping the motor frame, bearings and all. But the "better" bearings are themselves worn more than I would like.

I have also thought of trying to build up the insides of the bearings with Babbitt metal.

I am now contemplating drilling the bearings out to 3/16 inch and replacing the axles. I don't know whether I would try to turn down the axle ends to fit the wheels or drill them out also to fit the new axles.

Any advice or suggestions?

[SPFan]

Bob, I assume you have access to a lathe. If I were faced with this I would turn down the 3/16 axles rather than drill the wheels. It will be much easier to hold the axle on center. OTOH if you don't have a lathe then you might be able to ream the wheels but that might require a carbide reamer. As a bodge you might want to try some 1 or 2 thou brass shim stock inside the bearings, maybe tacked in place with a little solder.
Pete

[lionelsoni]

I got it wrong above. The "donor" bearings are the ones slightly under 3/16 inch. I pulled the wheels of the "patient" locomotive tonight and found that its bearings are worn enough to admit the 3/16 drill plus a little more in the vertical direction. Furthermore, their outside diameter is greater than the donor's, which DNA mismatch makes it ineligible as a donor of course. They are also clearly made of brass, while the erstwhile donor's are an unknown white metal.

Pete's suggestion of shims gave me the idea to try to put 3/16 brass tubing into the holes. It fits snugly. My favorite plan now is to solder the tubing in with tin-antimony, taking advantage of the gaps on top and bottom due to the oval holes, then drill the new surface out to the proper diameter with a succession of number drills. I would solder and drill one side before soldering the other side, to get the advantage of the existing bearing to align the drill. The tin-antimony should wick as easily as anything into the gap and would not be a bad bearing surface itself if the axle wears through the brass. What do you think?

p.s. I also discovered that the non-geared wheels on the patient have some fine cracks, whereas the doner's non-geared wheels are perfect. Its geared wheels are hopelessly rotten however; but, between the two I have four good wheels.

[SPFan]

Is Tin-Antimony what TIX solder is? I had some of this stuff years ago and have since forgot about but I see its still made and its claimed to be the hardest soft solder available. If so you might be able to use alone without the brass tube. The brass tube idea may work as long as the wall thickness doesn't get too thin otherwise I'd think the drill might catch it and tear it away from the bearing.
Pete

[lionelsoni]

I don't think they could be the same. The tin-antimony is 95/5 and melts at a higher temperature. I had never heard of Tix before; so I Googled it and never found a description of the, presumably proprietary, alloy.

I agree about the wall thickness; but I don't see any disadvantage to trying it anyway. I can always go to drilling the tin, or whatever, if it peels off.

[tmackinator]

Bob, I have been a machinist/industrial model maker for over 18 yrs. When drilling the brass tube, leave .015 on the i.d. and fini***o size with a reamer. Brass has a real tendency to grab a common twist drill. Use a lube like wd-40 or tapping fluid when reaming. Run the reamer fairly slow and feed in with a constant pressure as you feel it cut. you can also get oilite stock and make a custom bushing to fit your engine . Drill it out .015 under size on the borebefore you install it and use a punch with a internal pin that fits the bore of the bushing when you install it. This will prevent collapse. Pressing in is my recomendation. Finish ream to size after installing. Hope this was usefull.-TM

[lionelsoni]

I did one pair of bearings last night; and everything went well. I drilled the tubing to .182 first, but the knurling on the end of the axle gave me a little resistance when I tried to put it in; so I continued to .185 with no trouble--the inside surface appears to be all smooth brass. With the other axle, I think I will try a little harder (with a little oil) to get it to go into a .182 hole and, if that works, go back and redo the first pair of bearings.

I used my ancient Weller soldering gun to heat the joint. Since the first tip burned out 45 years ago, I have always used AWG 12 copper wire as a tip. So I just reshaped the loop of the current tip to wrap most of the way around the tubing and got ample heat quickly to solder the tubing in place with the tin-antimony. Then I sawed off the brass stock and filed the end flush.

Since this seems to be working, I won't try to replace the bearings, to avoid splitting the motor side plates apart unnecessarily.

[lionelsoni]

I think I'm done. I must have redone each bearing about 3 times before I got it centered to my satisfaction. I wound up with .182 holes. At one point, I broke a chip out of a wheel flange while pushing the knurled axle through the bearing; but I seem to have gotten a good fit with a super-glue bond. I hope I don't have to find another wheel. The solder turned out to be tin-copper, with no antimony, on closer inspection of the label.