Oil Leak

[jcsaintp]

I've now put about 1,000 miles on my (new to me) '84 R65 and she has devloped a couple of leaks. One on the right side valve cover. Methods of repair covered else where on this site, will try solutions suggested.
Of more concern is a definite 'wetness' developing on the sump beneath the transmission. I didn't notice at first until different (from aforementioned) drip on the garge floor. Engine oil level is good. I will check transmission level this weekend. I'll also try to determine if engine or transmisson fluid. Clutch isn't slipping. Appears to be coming from between engine and transmission cases. Thoughts?

Thanks,
Jeremy  

[Bob_Roller]

Most likely the rear main seal is starting to seep/leak, not uncommon on these bikes .

Check the fluid for smell, if it's gear lube from the transmission, it's smell is quite distinctive as compared to engine oil .

[Luca]

+1 on the smell.  I find that gear oil smells "skunky."

Also, if you gear oil was colored, you could use that to help identify the source.  I've had some gear oils that were greenish in color.  I think they were semi-synthetic though.  You might also be able to get a rough feel for viscosity.

Synthetic oils find their way past seals more easily than conventionals.  If you or the PO put in synthetic, you might find that switching back solves your problem.

And for more than you asked for... since the bike is new to you, it would probably be worth it to change the transmission fluid if you haven't yet.  The speedo cable boot has a habit of leaking water into the tranny, and if you have any water in your transmission it will kill the bearings in there.  Usually comes out of the transmission looking like coffee with cream.

[montmil]

That drippy "wetness" mess could be a leaking neutral indicator switch. The danged BMW OEMs are prone to leaking; some within days after replacing with a new one.

Try spritzing the switch clean with some WalMart carb/brake cleaner and watch it for a few day. That engine oil sump extension below the neutral switch will collect the drips in a pool and the distribute them randomly about the garage.

I use a Motobins Italian-made repop unit that is more economical to purchase and is designed just differently enough so as not to leak. Bargain times two.