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specialk6r

countershaft seal, again!

14 posts in this topic

There was oil slowly dripping from my countershaft, so I replaced the seal and the leaking stopped completely. It was totally dry with no leaking whatsoever for about 300 miles. After my last ride I noticed that there was dirt collecting around the shaft where oil was very slowly seeping from the seal. Is this normal, or should there be no oil residue at all?

I do like a clean engine, but the residue isn't enough for me to immediately worry about oil loss. Thanks for the imput.

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Are you over tightening your chain ?

I have only heard this and never seen it but if you over tighten your chain and put undo stress on the counter shaft your seal can leak.

Remember the chain will get tighter as the suspension moves through the stroke ,when the counter shaft is at a 180 with the swing arm pivot and the rear axle

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Are you over tightening your chain ?

I have only heard this and never seen it but if you over tighten your chain and put undo stress on the counter shaft your seal can leak.

Remember the chain will get tighter as the suspension moves through the stroke ,when the counter shaft is at a 180 with the swing arm pivot and the rear axle

You beat me to it dude.

Make sure your chain still has some slack when the suspension is near full compression (have a friend help you with this, use a tie down strap, or disconnect the rear shock). You're putting un-necessary stress on the shaft seal, & bearings, you're going to wear out your chain & sprockets faster because they are effectively acting as part of your rear suspension. Also, getting your rear suspension "dialed in" is next to impossible with this condition... Trust me, I know, I learned this the hard way on a road race bike.

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I blew out this seal earlier this year and it wasn't due to chain tension, I keep my chain nice and loose. When I changed the seal I must have damaged the new one putting it in because it leaked again. When I changed it a second time the leak completely went away and hasn't been back. A couple weeks later a friend of mine had the same seal start to leak. It lives in a vulnerable environment down there! When I wash my bike I take the chain off and I think I may have gotten a little too close to this area with the high pressure and caused my initial leak myself (oops!) Or maybe it was just the grit that seems to always be there. :applause:

Anyways, you may not need to be too worried about oil loss if it barely leaks, but it probably won't stop and you're gonna have to change the seal again. It shouldn't leak at all! Also be very careful not to nick or scratch the outer housing where the seal lives when you pull the seal out or it'll never stop leaking! It helps to clean the shaft with scotchbrite too before installing the new seal so there aren't any little rough spots rotating around and eating up the inside contact surface of the seal. :thumbsup:

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Thanks for the tips fellas. I'd say if anything my chain is a little slack. I can fit 3 fingers between the rear bolt on the slider block and the chain. Hopefully I just slightly nicked it putting on the last new one.

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When I wash my bike I take the chain off

:thumbsup: everytime you wash?? My god man, mine only comes off when it needs to be thrown in the bin!!!

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:applause: Yah your chain sounds about right. :thumbsup:

When you remove this seal you can see the empty spot that the shaft "floats" in inside the case, and the bearing behind the seal is centering it. A load on the front sprocket through torque on the chain loads that bearing backward and moves the shaft aft and distorts the seal center. I'm thinking this lets debris in and eats away at the seal. :applause:

The metal cover plate is there to stop this, but this doesn't appear to be the highest technology type of sealing system! Sh#t still can get through, either ridin dirty or pressure washing it in!

When I first changed this seal I ordered one (dumb!) and it took 5 days to get here. I thought they would've stocked it at the dealer but no joy. I had called around and no bike shops in town had one.

So I ordered it online. I managed to damage the seal putting it in!

Due to a race in two days I was desperate and went to Napa auto parts with the seal in hand. They measured it up and gave me a new seal. This time I bought a couple. I was more careful installing the next seal and it's been in my bike for 30 hours riding time and hasn't leaked a drop.

The dealer wanted $30 for the seal. For the first seal I changed I paid $6 us online + shipping + duty + gst tax=$16. Napa sells them for $4!

If any one wants to pick one up they're Part # at Napa is 12697 and the spec # of the seal is CR 32x42x7, and it's called a joint radial oil seal. :applause:

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Has anyone noticed you can install the seal in too far? When I rebuilt a 426 a few years ago if you did not leave it flush with the surface(case) the lip of the seal is in the splined portion of the shaft???

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Yikes! That'd be bad. The splines would eat it up.

I wonder if oil pressure would push it out to butt up against the retaining metal plate?

If it did it would probably already be foobarred. :thumbsup:

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Yikes! That'd be bad. The splines would eat it up.

I wonder if oil pressure would push it out to butt up against the retaining metal plate?

If it did it would probably already be foobarred. :thumbsup:

If the oil pressure was high enough, the first thing to go would be one of the half moons on the rubber head gasket. It sounds like your popping bubble wrap. It must have been designed that way?

Anyways, I don't think the oil pressure is causing your leak.

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I would also check your gear box breather hose for obstructions. if it is blocked and there is a pressure buildup it will force the oil out of the easiest orifice.

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My 2006 WR450F has developed a countershaft sprocket leak too. Thanks for the great tip on the NAPA part #! Saved me a bunch! BTW, what is the best way to get the old seal out without damaging anything?

Thanks for the help!!!

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