Hi!

Recently my rear end started to feel abnormal, and since I've already done this I popped the rear open. After determining that my new-to-me shaft is, in fact, okay, I started to investigate further.



Not a professional bike mechanic, but my guess is that it shouldn't make that noise

So, my question is - what parts should I get to properly repair this?

I've found this topic and it says I need the bearing (obviously), a new o-ring and the main seal.

I'm planning on replacing the o-ring and the bearing. A new main seal costs an amount of money, and the current one looks okay-ish - should I leave it as-is or is it a very vital part to have brand new?

Thanks in advance for any answers or info!

That indeed sounds like it could be a dead main bearing. As for the seal; if you were very careful in disassembly and can be absolutely sure that you did not catch or tear the lip, then it should be safe for re-use.

Dai wrote:As for the seal; if you were very careful in disassembly and can be absolutely sure that you did not catch or tear the lip, then it should be safe for re-use.

I wasn't exactly careful with the disassembly, but I did disassemble it vertically so the wheel hub fell straight out.



The seal looks and feels smooth, with no notches, and the rubber isn't dry and doesn't feel old. And if it leaks I'll replace it, Winter is coming so no rush, and plenty of time to observe it

Dai wrote:That indeed sounds like it could be a dead main bearing.

Doesn't feel VERY worn, but it is rough.

Replace it, that saves you losing the rest of the final drive. Mine was like that wasn't really any discernible play but it FELT different and my expert friend confirmed it was gone. Bearing replaced without even removing the final drive. We had done a rear main seal and spline lubes etc a few months before and knew the rest was all good.

92KK 84WW Olaf wrote:Replace it, that saves you losing the rest of the final drive. Mine was like that wasn't really any discernible play but it FELT different and my expert friend confirmed it was gone. Bearing replaced without even removing the final drive. We had done a rear main seal and spline lubes etc a few months before and knew the rest was all good.

Oh don't get me wrong, ANY roughness or play in a bearing means replacing it. Especially since it's a rather important bearing.

I did replace the main seal as it's not very expensive but the old one seemed absolutely fine.

Do you have a plan to get the old bearing off?

Snod Blatter wrote:I did replace the main seal as it's not very expensive but the old one seemed absolutely fine.

Do you have a plan to get the old bearing off?

I carefully cut the old bearing (not even a scratch on the gear) and I plan to press the new bearing on - my friend has a press in his shop.

I found a local bearing store in which I ordered the brand new bearing that also has similar looking main seals, I'll bring the entire cover with the main seal to this store on Friday (when the bearing should arrive) to check if it fits.

Put the drive box in the freezer for a couple of days (yes - it needs to cold soak). Put the bearing in the oven on the lowest heat possible for around fifteen minutes. You may find that the bearing is then a push fit rather than having to press it on using a tool. I'm old - I used to replace main bearings in two-strokes and big Japanese singles using this technique, except that it was the other way around - cold-soak the bearings and cook the crankcases.