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Sunday, October 13, 2013

Resealing the Main Drive Gear: How-to, How-not-to, and what might work

Man this thing was leaking. This is what it looked like when I took the clutch hub nut off with an impact gun.

Time to pull the hub and the bearing support plate to see what's up.

Yep. The main drive(4th gear) seal popped out. Remember I modd'ed this to take two seals. I have no idea why at least one didn't hold.

ugh. That came out with no effort and was mangled.

There's the second seal.  It took more effort, but it wasn't holding anything in either.

I had my suspicions that this seal was my problem and I had another solution to try. An Evo five speed will fit and it's a better seal overall.

Double lipped already.

So I want to grease the inside and Motoseal the outside.

Then install with a Jim's tool #2256. Dhelding lent me this one.

Slide the seal down the shaft. Grease on the shaft and Motoseal on the outside.

A couple whacks to seal it.

Ooops. So I discovered that with the bike on the sidestand and the blows not delivered perfectly that you will destroy the seal. I put way too much faith in that tool. Usually I buy two seals or gaskets for every one I need, but not this time.

I can't get a new Evo seal until Tuesday. I do still have two spare 12022 seals that I can use. The trick to the tool is to spin the sprocket and shaft after every blow to make sure the seal goes on straight.

With the first seal seated as far as the Jim's tool will seat it, I grabbed the nicer of the two used seals that I pulled out of the gear earlier, and drove that seal on top of the new good one.

I pulled the one bad one out again. Then installed another new old style seal (with Motoseal) but not as deep as I had drove the used one it.

I must have quit taking pictures about then, but if the two new old style seals don't hold then I will tear it all apart again and do the newer style seal. I will be more careful installing that one for sure.


  1. this is the fix:
    if its coming from your drive shaft
    its the spacer with two seals and it def works
    You seem to be shutting the door after the horse has bolted, or something like that, haha - good luck

    1. Yeah, this transmission has Ray's(saddlebagrail) spacer with o-ring and the fourth gear was bored to take two seals, That's one of Ray's tricks, too. I'm not sure why the seals didn't stay in place. That was clearly the leak.