Friday, July 24, 2015

ural drivshaft repair

I few weeks ago, I had a sticky rear brake so I was inspecting things when I noticed some serious wear in the Ural driveshaft. The u-joint had disintegrated due to lack of grease (there was no grease zerk as there are on later models). I assume this had never been looked at by any of the previous owners and I had obviously neglected it and riding all winter probably didn't help the situation. The driveshaft yoke was ground down from the wear so I figured a new driveshaft was the solution. I thought fitting the newer style removable yoke sections from a late model Ural would be the way to go, but it would require dropping the swingarm, and with seals, shims and such, I was looking at over $250 in parts alone. It happened that as I was shopping, I found someone (on the soviet steeds black market) who had an early style driveshaft, u-joint, end drive fork, and shims for $20 that appeared to be brand new. Two days later I had the drive shaft in hand. When I tore into the rear-end, I discovered some metal pieces inside the brake and drive spline area. I panicked at first thinking it was the drive splines, but discovered the brake shoe pivot had slid out of it's casting boss and was grinding on the inside of the wheel hub. After a thorough cleaning I had the pivot reseated and everything re-greased. The new driveshaft is a fine spline shaft, but I don't think that will be a problem. I assume that Ural made the switch from course to fine splines at some point. Since I had the replacement drive fork that matched the driveshaft this was no problem. I made sure things were properly lined up and shimmed when I installed the new shaft.  If the square pin in the shaft is not properly located then you can crack the pinion (see this article). Also Gobuim shows the correct yoke alignment here (for future reference). Maya came out and helped and even took a few pics while my hands were dirty. Even though I was dreading this, it ended up being a fairly easy repair. The new u-joint has a grease zerk so I will be sure to maintain this so I don't have to do it again for a while. I'm bag riding the Ural and everything seems to be good. I did swap the rear wheel with my spare as the knobby tire had worn a bit during this last stretch of riding. I'll try to keep these in regular rotation to make them last.

No comments: