HELP!!! Does a new driveshaft oil seal need time to seat?

[agent32]

So I just replaced the driveshaft seal on my 99 YZ400. Seemingly simple project - I remove the front sprocket and the seal cover (held on by the two bolts) and pop the old seal out with a hook. I oil up the new seal with motor oil and slide that baby in - put the cover back on and fire her up and see some pretty serious spooge coming from the area.

I turn the bike off and remove the cover to realize that the seal possibly wasn't perfectly even all the way around so I use the square blunt end of a screwdriver socket adapter and tap it even so the new seal is evenly slighly countersunk all the way around - put the cover back on and fire it up, let it run for 10 minutes and as soon as I start hitting the gas a bit and putting the seal under any kind of pressure, I'm getting some pretty decent discharge from the new seal area....

Another thing, I bought a new o-ring like I was advised by my parts guy and couldn't figure out where to put it! It looked from every scematic I saw that the o-ring sat behind the bearing? I didn't see an o-ring when I removed the old seal either??

My roomate has been wrenching on cars for years and insists that the seal just needs time to seat and the leak will stop soon.....but I'm not sold!

Any help would be greatly appreciated

The worst part about it is the old seal was barly leaking!

Thanks in advance.

[grayracer513]

I'm assuming here that you mean the countershaft, or output shaft seal. I don't have a YZ400 manual, so I'll refer you to the Yamaha Parts page:

http://www.yamaha-motor.com/sport/parts/home.aspx

Punch up the fiche for a 99 model and go to the transmission page. The O-ring is item 27. It goes Underneath the collar, item 26, which the seal rides on, and seals between the shaft and the collar. There is groove for it to ride in just behind the splines on the countershaft.

You'll need to pull the collar off the shaft to change the ring, and while you're doing that, you can check the collar for a groove worn into it by the seal. If one is present, and is much more significant than just a shiny wear trace, it will keep the new seal from holding properly, and you'll need to replace it.

[agent32]

Gray - Thanks bro!

There is no need to replace the bearing here right? Any technique to getting that collar off? The o-ring should be right underneath it?

[CHEEZE13]

Side note use Lithium spray lube on all seals not motor oil.

[grayracer513]

There is no need to replace the bearing here right? Any technique to getting that collar off? The o-ring should be right underneath it?

Unless the bearing is rough or loose, it should be OK, although from outside, it can be a little tough to tell.

If you're lucky, you may be able to pluck the collar off with a pair of pliers (careful not to scratch). If you're unlucky, you'll have to remove the seal and pull it out with a small pair of pick tools. Look at the illustration and you can see that it has square notches cut into the inboard end. You can catch a hook in these and pull it out. The O-ring is just behind the splines.

[Doug.]

I'm assuming here that you mean the countershaft, or output shaft seal. I don't have a YZ400 manual, so I'll refer you to the Yamaha Parts page:

http://www.yamaha-motor.com/sport/parts/home.aspx

Punch up the fiche for a 99 model and go to the transmission page. The O-ring is item 27. It goes Underneath the collar, item 26, which the seal rides on, and seals between the shaft and the collar. There is groove for it to ride in just behind the splines on the countershaft.

You'll need to pull the collar off the shaft to change the ring, and while you're doing that, you can check the collar for a groove worn into it by the seal. If one is present, and is much more significant than just a shiny wear trace, it will keep the new seal from holding properly, and you'll need to replace it.

Your wrong. You dont have a clue to what your talking about.

Dont worry about the static this guy speaks, its false information. New driveshaft oil seals DO NOT need time to seat, I speak from experience many times in this situation. Listen to me. Just install the thing and go max RPM riding.

[Doug.]

, Just kidding.

[agent32]

thanks for the help y'all....

I suppose my best move would be to order a new collar, seal and o-ring and carefully replace everything....

I guess there is no sense in seeing if the already installed seal will eventally seat, huh?

[grayracer513]

At this point, I don't know that you are certain that the seal itself is leaking. The O-ring is the cause of a leak only somewhat rarely if it's been undisturbed ( the collar hasn't been pulled off).

I would try to pull the collar to check for a groove. Only if I had to remove the seal to get the collar off would I remove the newly installed one you now have. If the collar was not worn enough to be a problem, I would reuse it, replacing the O-ring in the process, and just assume I had damaged the oil seal during the installation. As far as evaluating the wear on the collar, the simplest rule is that if you can feel it with a fingernail, the groove is too deep.

[agent32]

Thanks for you help - I will let you know how I make out!

[old man dan]

One thing I noticed is that you said you drove the seal in with a blunt screwdriver, you should try to find a socket or ideally a piece of plastic pipe that fits over the shaft to drive in the seal. A screwdriver can bend the seal. Try to keep everything square while you drive it in.

[bob333]

yah that helps a lot

[agent32]

FIXED!!

so far anyway....the problem (I think) was that the spring on the new seal got mangled when we put it in and it wasn't holding properly....also, we used motor oil to lube up the seal during first installation, this time we used lithium grease....

so a combination of the new seal with the old seal spring, a new o-ring and some lithium grease seemed to do the trick! Thanks for all the help TT!

cb

[machoman_#618]

Well I've been a maintenance man for 20 years and counting. You seat a seal when installing. If it leaks you did it wrong or it was designed to leak. Install is the key not time afterwards. But its a good question for those to learn from IMO.