Sunday, July 14, 2019

Ural Throw out Bearing

Felt good enough this afternoon to remove the throw out bearing on the Ural. As expected, it was pretty much toast. If you look closely, you can see one deformed ball from the ball bearing. Most of them fell on the floor when the pieces were removed. This assembly is located at the rear of the transmission and it engages the pressure plate by a rod running through the input shaft into the clutch. Just like the dry clutch on the BMW airheads.

There wasn't much oil there as it is supposed to be lubricated from the transmission. So I should check the transmission fluid level. I did lubricate the bearing and other components with assembly lube which is grease with a high moly content. It actually looks and feels like the Honda grease used on the transmission input shaft splines. I just happened to have a spare throw out bearing as I had ordered the whole assembly when I rebuilt the engine. The old throw out bearing still looked pristine so I used it over. Especially since it is very easy to access when needed. Such as now.

Later - Transmission oil level was fine. Test drive to the university and gas station was fine. Just like before. I still wonder why the bearing failed...

Monday afternoon - I went ahead and removed the throw out bearing again to make sure that it was getting oil from the transmission. Now that I know better, I didn't remove stuff (air cleaner housing, starter, battery, seat) to get access. I simply removed the pivot bolt and pulled out the bearing assembly. Maybe two minutes tops and that included getting out the tools. The bearing was awash in oil. Enough oil such that the assembly lube was partially washed out. So, it looks good for now but I still don't have any idea why the bearing failed...


  1. I think it's just possible bad metallurgy, wear and tear. I tend to put the gearbox into neutral when at stop lights to reduce wear on the assembly. Don't know if it makes a difference, but if nothing else, it's a placebo for my mind.

    1. I usually put it into neutral as well. The tank shifter makes it pretty easy.