1985 K100RT with a progressive oil leak.

[Roadhawk]

1985 K100RT, 66,000 miles

The leaks seems to weep slowly on the sides of the gearbox case (see photo), there is more of a leak on the bottom. After a long ride I will find one or two quarter-size dots of oil on the floor.

The concern is if this is a sign of worse problems to come. Anybody with experience with this type of a leak on the K100 will be greatly appreciated. I am guessing that it won't be fun, or cheap to fix.

Thanks for your help.

[deilenberger]

Actually - very common, especially as the K's get older.

There is an O ring used to seal the shaft the clutch assembly fits on where the shaft comes out of the engine. This O ring gets old, hard and dried up with age, and you start seeing leaks like this. If you smell the oil - it should have basically no real odor to it - that's engine oil. If it smelled like sulfur - it would be tranny oil, but in this case - I'd bet a beer it's the O ring.

LUCKILY - this rarely ever causes clutch problems. The oil seems to make it's way out without soaking the clutch disk. What you should consider doing (or having done) is a clutch spline lube. That would be the time to take care of this O ring. You do 70% of the labor doing the spline lube - replacing the O ring takes about another hour if you dawdle.

Almost every K bike over 10 years old leaks some oil there - your bike is about 23 years old now - so a bit of incontinence is to be expected.

[Roadhawk]

Oh man, K-Bike incontinence. Thank you for your insight.

I will try "O-Ring". If you have K-Bike incontinence, or better known as "KBI" ask your mechanic if O-Ring is right for you. Some side effects may be increased fun, riding without worry, dry garage floor, clean motor syndrome, less need to add oil, some riders experience a lighter wallet. Live to ride, ride to live with O-Ring.

Seriously, I'll see if the average schmuck like me can handle this operation.

Thanks again

[jdiaz]

I just did this job with a buddy of mine on my K75 a couple weeks ago. Its about five hours work. I would also change the alternator rubbers and be prepared to change out the swingarm bearings as well, if they are original.

You will need to purchase the big o-ring, a new nut, six new washers for the clutch assembly (I would buy new bolts too), and the aforementioned clutch dampers and swingarm bearings.