[Guest]

Came back from a hard ride on my 99' M900 and found oil leaking ot of the bottom of the clutch cover. What happened?? Did a seal let go behind the clutch? I'm pretty sure there a crank seal back there, but have never worked in that area of this bike before. Can anyone tell me what I'm looking at fixing? Would extra oil cause this? I'm about 3/4's of te way between the min and max lines on the sight glass.

 

[Mark1305]

I've got it too on my 95 M900. It could be either the large seal around the outside of the "driven" primary gear where it goes through the right side crankcase cover. Or could be the smaller seal that goes between the inner surface of the driven gear and the center hub of the clutch. Oil from either source gets slung to the same place - the outside perimeter of the clutch housing.

I've been waiting on the dealer to get a right side crankcase cover gasket. The other necessary parts are all there waiting on me. When I go into mine, I'm going to replace both seals mentioned above as normal good practice. To do it right, there is also a crankcase end bush seal to replace, an oil galley o-ring, and something else I can't remember without pulling out the Haynes manual. Something like seven seals, rings and gaskets total. I'm giving up on the case cover gasket and switching to silicone sealant as many others have done.

As long as the leak isn't bad, you can keep riding. Just clean out the excess oil occasionally (don't spray solvent cleaners on the clutch release bearing) and keep an eye out that the leak doesn't get bad enough to oil the back tire or lower the oil level below minimum.

Mark J

 

[908SSP]

>I've been waiting on the dealer to get a right side
>crankcase cover gasket.

There hasn't been a gasket there in I don't know how long. Yours isn't the first time I have heard a dealer claiming they need a gasket that doesn't exist. There are better products then silicone these days, one is a gray paste one brand is Yamabond there is another 1104 or something like that. Another product looks like silicone but isn't it is red made by Loctite it is an anaerobic gasket eliminator. The advantage of these products is they don't harden in air so they don't leave pieces of silicone floating around your oil they only harden between the mating surfaces of the case.

 

[Mark1305]

Yeah, thanks for the reminder on better substitutes. I'm planning on using that type of product rather than the garden variety RTV gasket makers.

Mark J

 

[byrdseye]

The most likely source of your leak is the big seal behing the basket. Its the one that leaks 90% of the time. The good news is that you don't need any parts to fix it. Pull your clutch cover (a brass drift down the oil filler tube is helpful)
and pull the spiral spring off the inside lip of the big seal.
This is what provides tension tho the seal. "Unscrew" the spring where it is joined into a circle and notice there is a tapered end and an open end to the spring. Cut the open end off about 3mm and screw spring back together. Reinstall on lip, smear grease on the seal and put it all back together.
BE SURE TO PUT THE ORING for the oil pump crank pressure circuit in place with grease or you'll sone need a new motor soon! The other seals that can cause the leak you have (not likely but it does happen) are the smaller center seal on the shaft, the oring on the shaft behind the steel spacer or the tiny seal in the center of the shaft that the pushrod goes thru.
If any of these leak......replace them.
Hope this helps
bb

 

[Guest]

Does anybody have a breakout view of these seals from a manual or parts list? It would help me when I go to the dealer to make sure I'm getting the right seals. If you could email it to me at [email protected] I'd appreciate it.

Thanks ;D

 

[Mark1305]

Even though it only covers through 96, the Haynes manual for 2V twins should be a good reference for a lot of stuff that just doesn't change from year to year. Just use it with caution.

That's where I worked up my parts list to phone in to the dealer.

Don't have part nos., but I'm planning on replacing:
1) Crankshaft end bush oil seal
2) Large oil seal between case cover and outside of driven gear.
3) oil seal in front inside of driven gear.
4) o-ring in oil way (very important)
5) o-ring for clutch guide (inside groove)
6) o-ring between clutch center and large thrust washer
7) Instead of case cover gasket (made of unobtanium) will use high quality gasket maker compound

Mark J

 

[Guest]

OK,

Thanks for all the input guys! Now it's time to get this done so I can ride some more before the weather gets too cold. My local dealer has the large seal behind the basket and another common leaker in stock, so I figured I'd go and replace those. Now my problem is how do I get the clutch basket off without air tools? My compressor died on me and I've never taken a basket off without one. Anyone have a trick for keeping the motor from turning while trying to remove/install the large nut.

Thanks for your help ;D

 

[Mark1305]

The Haynes Manual (gotta love it!) has a bunch of tricks and tips and how-to to make tools instead of buying them.

Among those, it shows a clutch center holding tool made of two pieces of flar stock approx 24 inches long; bolted together about a third the way from one end like scissors; the short end has about 2.5 inches bent over at 90 degrees and the inside edges of those "jaws" filed to engage the grooves in the clutch center where the plates would be engaged. This tool lets you hold the center to get the big nut on or off.

Mark J

 

[Guest]

Thanks again!!! I guess I need to look for a Haynes manual now...

 

[Mark1305]

MotoDuc,

I sent you an email at the address you posted above with some part numbers.

 

[Guest]

The same thing just happened to me yesteday while cleaning after a ride I noticed just a few drips of oil-like substance under the bottom bolt on the clutch cover?

But, after taking the cover off I noticed there's a little notch in the cover right there? Almost like it was meant to allow it to drain? Has anybody else notced this?

I have a 2000 M900ie Dark......
I'm just wondering if this could be "normal" ?

 

[Guest]

after a ride I noticed just a few drips of oil-like substance under the bottom bolt on the clutch cover?

I'm just wondering if this could be "normal"

 

[Guest]

Thanks for replying MarkV

are you sure it was oil and not a combination of water from cleaning and clutch dust?

Good Point. I finished cleaning and put the cover back on and
am going to keep an eye on it. If it happens again then I guess I'm going to have to join the club and start replacing stuff....

I've never worked on my DUC but my husband is extremely mechanically inclined. He hasn't worked on our DUCs, yet either. (We haven't had problems before this)

Question for ALL that have been here before:
In your opinion how would you rate the difficulty in replacing the seal(s)? Is this something the we (he ) could do, or should we consider bring her in? :-/

Thanks in advance for ANY advise,
wynot

 

[Mark1305]

Wynot,

Just keep an eye on it. As long as it's a slow weeping kind of leak and not a real drip or stream it's not a show-stopper.

I've had my bike about 14 months, and have been watching my slow oil leak from the clutch for at least 10 months.

Don't know if you saw my comments in an earlier post, but I used to use brake parts cleaner to get the mix of clutch dust and oil out every so often. Even though I tried to keep the solvent off the clutch release bearing, I thought I heard some new noises when pulling in the clutch with the engine running and the cover off. So I replaced the bearing as a precaution and quit with the spray solvents around any bearings. Now I'm just wiping the goo out before it runs out the little drain hole and down the crankcase. So far the oil is staying out of the clutch basket thanks to centrifugal force.

 

[Guest]

Mark J - I appreciate your replies...thanks..

I didn't have anything on my clutch plates, just dust inside of the cover and about 4-5 drops of goo-stuff. I just wiped it out with a clean rag and put it back on.

Also, I have the stock closed cover. I was wondering if the open covers would allow more road/air trash into the cluch plates? hmmm....