gearbox output seals

it seems that the output seal behind the sprocket causes problems i went riding yesterday only to lose all the engine oil and nipped the engine up. although it was pretty full of mud in there, on taking apart this evening sure enough the seal had completly destroyed itself, it was interesting to notice though that the spacer from the mainshaft had the start of grooves worn into it where the seal sits and that it was quite pitted with rust and crud undoutedly the seal was ripped by the spacer, has anyone else had this happen? it seems to me that if the spacer was made from stainless steel it couldnt rust and cause the seal to get eaten in this way any comments apreciated and if enough interest i might get some spacers made.



sick 2000 drze

by the way my 2002 will be here on 13th december why couldnt the problem happen after that date

Tom it looks like joedrze had the same problem and has blown his motor aswell,can you let me know on the s/steel spacer front, cheers damage

So this has happened to at least two different poeple. I can probably have some made.


Never had this problem but i took the sprocket cover off from when bike was new as dirt builds up behind it if left on and thus can damage seal.

I kept the chrome chain guide and spacers on though.


01 400S

[just to update everyone i have just been to the engineering shop that i use and ordered a batch of spacers in stainless anyone interested in one they will be here next week.

i will ship worldwide at cost

hope this helps


[ November 28, 2001: Message edited by: dendrz ]

Disregard that last post i just realised i was thinking you were replacing the spacer with one that acted as an extra seal.

[ November 28, 2001: Message edited by: dendrz ]

[i didnt know that the s model was different not having gotten that close to one, the e model has a flat sprocket with the spacer behind it interferance fit on the shaft and the o/d running on the seal

[ November 28, 2001: Message edited by: dendrz ]

Tom I assume you are having the spacer that has the sealing surface on its OD and a groove for an O-ring on its ID. This is different than the shim that the other guy is talking about. I just took mine off and its a fairly complicated part to machine. I also discovered that getting this coller back on without fouling the inner O-ring with sand is not going to be easy. Any dirt in the output shaft splines will end up in the O-ring.


[hi perry

yes that is the spacer that im having made, the shop that is making them said no problem at all, although i wouldnt like to try!




Just to be clear, are the parts we are talking about:

23 Seal

39 O ring

34 Spacer

Is it the spacer that you are having made?


Ash, that helps :)

So the spacer is common to all Drz models and the only thing missing from that illustration is that shim that Perry refered to if we use certain makes of 14T sprocket, correct me if i am wrong.



thanks ash yes 34 is the one


tom :)

just another observation for everyone and please any comments apreciated, these seals seem to be an achillies heel ive read and heard that if you overfill the oil the seals can blow, we already are talking about rust and there is also the problem of the possibility of crud getting in.

i dont want to get stuck out again, certaintly not on a rallye or in the middle of nowhere, i will from now on carry a seal on me and box spanner to get the sprocket off, however the screws on the plate that guards the seali had to get off with an impact driver which is ok in the workshop but not on the trail my solution to this i think would be to change the screws for allen screws preferably stainless ones then job done in a few minutes on the side of the road. comments please as to whether this is a good idea or not?

There are a number of things that can make seals fail only one of which is corrosion of the spacer. Mud, sand, water, pressure washing, and never washing can all lead to the problem. If you ride in mud a lot checking that seal daily is not a bad idea. Another thing that can help is washing your bike after a heavy mudding and then ride it around to dry things off before you put the bike up. Usually seals start to leak before they totally fail, which is the time to replace them. Sometimes something will get wrapped around the shaft and cut the seal. If corrosion is the problem it is not going to be fine one day and then poor out oil the next. Only thing I can think of is something cut the seal and made it fail immediately. Also the overfilling theory might have some merit but I would not think that is would cause such a bad leak as to pump all the oil out on a single ride. The seal has a retainer around it to keep it from popping out so somebody has done their home work. This is the first bike I have seen with that feature. An oil pressure light might be the best insurance.


[ November 28, 2001: Message edited by: perryg114 ]

[ November 29, 2001: Message edited by: perryg114 ]

spacers are here and ready, ive had a limited batch made anyone want one just contact me £16 each i will ship worldwide

With a dry-sump engine which the DRZ has, is it possible to "overfill" with oil... wouldn't the engine when started cold, just pump all that oil up in the tank which would overflow at the vent line? My understanding is that all the bulk engine oil is kept via the pump up in the frame tank, not in the crankcase. Tell me where I am wrong... Urge

That is a good question. I would think that if there is no overflow line in the top of the frame that if you overfill the excess oil would end up in the crankcase. If you overfill the crankcase then it will come out the crankcase vent. I expect there is an oil passage at that output shaft bearing and when the seal goes all the oil gets pumped out. On a wet sump splash fed engine there is no oil pressure on that seal.


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