While waiting for some spares to arrive, the DT has been sat on it's side stand, and I notice that it has been dropping oil.

Pretty sure it is not from the gearbok sprocket oil seal - it looks like it may be comming from the clutch actuator as there is a doplet of oil in the operating arm.

Not been able to find any detailed diagrams, but I assume that the actuator shaft that runs up from the bottom of the engine probably has an oil seal along the way, can someone confirm if this is the case, and whether it can be replaced without stripping the engine.

It is not a big leak just enough to make the underside of the cases oily and drip a little on the grouund.

Thanks.

Yes it is a seal, I had to replace one on my 76 DT400, not a hard job and no you don't have to split the case. The service manual has the directions on how to do the job.

Good to know it is not a difficult job to do - I have looked at the service manual, page 19 shows the exploded diagram, page 18 has the instructions.

I assume that the oil seal is located where the shaft enters the cases - do I need to drain out the gearbox oil before I change the seal?

Need to keep asking as I have not had the bike long so dont know my way around them that well.

Thanks.

It's been a few years but I'm thinking that if it's leaking oil then yes you will need to drain first, I'm sure I did.

No problem to drain the oil so had just as well do it.

Been thinking I had just as well replace the gearbox sprocket oil seal and gearshaft oil seal if both can be done without splitting the cases - looks like you can with the gearbox sprocket. not so sure with gearshaft.

No idea how long the bike had been layed up before I go it, so the sprocket may well have rusted and damaged the seal so probably worth taking a look as I hate oil leaks no matter how small.