Question about sprocket shaft bearing nut

Transmission, clutch, chains and belts
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Question about sprocket shaft bearing nut


Post by 03Roadking » Fri May 19, 2006 11:20 am

Description: Do I replace it or is there a good chance all it needs is to be tightened down

Post by 03Roadking on Jun 5, 2005, 6:06am

While I was waiting for parts I decided to pull the primary cover off today and install a hose on the crank case breather, figured I run it back to th chain, anyway I noticed a little bit of oil coming from the back side of the front pulley (belt drive) I took the pulley off and I noticed the oil is not coming from between the shaft and the seal but from the threads of the Bearing nut. I looked at all three of my books and they explain how to take it off and put in on but it doesn't say how tight (no torque spec) so my question is do I replace it or is there a good chance all it needs is to be tightened down I'd hate to put it all back together just to have it still leak but I'd hate to spend 25 bucks that I could use for something else, so I thought I'd ask

Post by 57pan on Jun 7, 2005, 5:58pm

Well, I was kind of hoping someone would chime in on this 'cause I was curious myself. So, I'll just throw in my .02 on the subject.
First of all - it's a straight thread so tightening it is not going to make the threads seal any better like it would if it were a tapered (pipe) thread. When you tighten it you are just putting more pressure against the outer race of the bearing. Of course, if it's real loose, tightening it might help.
I don't think I would try using any kind of sealer on the threads for fear of getting some inside the engine where it could plug an oil passage.

Maybe someone else has some ideas.

Post by 03Roadking on Jun 7, 2005, 7:19pm

Thanks for the reply I was beginning to think it was a really dumb question that didn't require an answer I ordered the part last Sunday anyway. the thing that I noticed is J&P sells the wrench, two versions one is a straight bar and one is a flat disc for ratchet but they won't work with the crank in, so I figured while I was waiting I would make one like the old spanner wrench type or is there someone that makes one that will work?

Post by CknDnr on Jun 7, 2005, 10:44pm

I made one out of the old nut/seal, using some pins made from a drill bit and welded the nut to a piece of pipe. It wasn't pretty, but it worked. Next time I would get something like this.

Post by 03Roadking on Jun 8, 2005, 3:56am

That is really nice ;D I think what I will do is take the new part to the tool crib up the street. This guy is a retired machinist, he opened this little hole in the wall selling specialty tools he's my go to guy when I have problems with a mechanism and need to make a new rail or cam line thanks for the idea ;D

Post by 03Roadking on Jun 20, 2005, 5:10am

I thought I would finish off some of these threads I started just for the next generation that needs help
First the guy that put the last shaft seal in thought it would be a good idea to hit it with a chisel you know just to make sure it didn't back out It took a little while to get it out and then I sat for two hours cleaning up the threads and I screwed up the threads on the new one because I wasn't patience enough, so I had to run down and pick up another 20.00 lesson > funny thing when I got back it screwed right in but when I went to tighten it, nothing it just kept turning I thought I was a dead man but for some reason I decided to mike them the one I took out was 2.485 the one i screwed up was 2.492 and the one I just bought was 2.376 so I took it back and showed him, he brought out the whole box it seems the ones with the red bull (didn't see the name) on the box are all under so beware the new one went in and looks like it's going to work fine
Thanks for everyones help

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