I purchased 80+ new Bachmann engines - DD40AX, SD40-2 AND GP40's prepping for my retirement. I inspected 30 DD40AX's, 240 drive gears, 42 where split. Inspected 25 GP40's, 100 drive gears, 4 were split. Inspected 25 SD40-2's, 150 drive gears, 0 were split. I am in the aerospace industry and have all kinds of structural adhesives for gluing spars and stuff together. So, in the turbine shop I found a 30+ year old bottle of Loctite 271 thread locker. I'm in the kitchen watching my wife baking cookies, the oven is running about 200°F, this is where I get my lesson in crossover chemistry for model trains. Loctite likes a flat clean surface, the inner surface of the gear hub is flat enough, the outer surface of the wheel axel is flat enough, I cleaned off the gear hub and axel with electro-wash cleaner degreaser (plastic safe) P/N: ES1210. Loctite likes oxygen starved places with tight fits, I put a drop of Loctite 271 in the gear hub and a drop on the axel, with my thumb pressed the axel into the gear hub. Now you have a thin oxygen free layer of Loctite tightly between the hub and axle. Using the NMRA HO standards gauge, MARK IVb I check that the wheel width is correct, now you let it cure overnight. However, I sped up the process so I could see the results. I took the gear drive and chucked it in the oven on the cookie sheet with the cookies for 60 seconds at 200°F then pulled it out and let it cool. I tried to pull the gear drive apart with my fingers, its flipping magic I couldn't pull the gear drive apparat.
(https://images12.fotki.net/v1686/fileapoZ/e4d17/4/4125954/16525067/Picture2.gif)
Clean gear drive wheel assemblies with the electro-wash cleaner degreaser (plastic safe) P/N: ES1210. Inspect the outer end of the gear hub for splitting or elongation.
(https://images15.fotki.net/v1673/fileHEdI/e4d17/4/4125954/16525067/Picture3.gif)
Holding each wheel pull away from each other.
(https://images49.fotki.net/v1680/fileSmdc/e4d17/4/4125954/16525067/Picture4.gif)
The wheel in a split hub will pop out.
(https://images34.fotki.net/v1681/filepOep/e4d17/4/4125954/16525067/Picture5.gif)
Apply a coat of Loctite 271 in the clean gear hub axle receptacle.
(https://images15.fotki.net/v1685/filekw3u/e4d17/4/4125954/16525067/Picture6.gif)
Apply a coat of Loctite 271 to the clean wheel axel.
(https://images15.fotki.net/v1685/file1fAZ/e4d17/4/4125954/16525067/Picture7.gif)
Insert the wheel axle into the gear hub receptacle. remove excess Loctite.
(https://images14.fotki.net/v1683/fileb4Xz/e4d17/4/4125954/16525067/Picture8.gif)
Using the NMRA HO standards gauge, MARK IVb check that the wheel width is correct.
Allow the repaired gear drive wheel assembles to cure overnight.
(https://images14.fotki.net/v1683/filelzhm/e4d17/4/4125954/16525067/Picture9.gif)
After running four DD40AX's for 4 years accumulating 50+ hours of run time, all gear drives repaired with Loctite 271 passed the pull test.
(https://images20.fotki.net/v1638/filegG4i/e4d17/4/4125954/16525067/Picture10.gif)
(https://images49.fotki.net/v1680/fileGK4P/e4d17/4/4125954/16525067/Picture11.gif)
To make a long story short, you are basically glueing the spilt hub back on with Loctite. Right?
I know all about the pre-retirement Model Railroad roster bulk-up purchasing. While I had an income to support it all. I built my roster of steam engines up to well over 60, I'd have to count to be certain. Some of them will probably hardly ever run at all, but I wanted them for so long, I got them anyway.