/5 Oil leak

[Adirondackbob]

1971 R60/5 154,000+ miles

At bottom end of the engine is a rectangular bowl shaped depression with a small drain hole at the back end.

I am starting to get a little oil there.
The oil appears to be coming from the forward part of that bowl shaped depression.

Quantity is about 4-5 drops after a ride of any length.

There was never an oil leak there before and this has just started in the last couple of thousand miles.

Opinions as to the source of the leak would be appreciated.

Thanks,
Adirondackbob

[lkchris]

Rear crankshaft seal.

Go to Airheads forum.

[DarrylRi]

Moving this to the Airheads area.

[20774]

Not sure I completely understand where the leak is but it could either be the rear main seal or the input seal to the transmission. See if the oil has a sulphur smell...that would be gear oil. Otherwise, it's coming from the engine through the rear main seal.

[PHMarvin]

Could also be a loose oil pump cover or a leak past the oil pump "O" ring.

[44006]

Sounds normal for bike of that mileage to get small leak from rear crank seal into clutch area or from transmission input shaft seal into clutch area.

The oil drains out hole in back of engine under transmission and pools in an
area often referred to as the "shelf"

I ride a number of very used and abused bikes some of which exhibit this problem. The thing to watch for is how fast does it get worse. If it gets
worse quite fast then maybe the seal is failing because the bearing is going and this is serious. If it just continues in regular small amount then you
might try my method for an old beater I ride in Florida about 15k mi/yr.

When I leave the restaurant I keep my napkin and shove into the tray.
When the napkin looks yellow I put in woodstove and replace - usually
about 1000mi/napkin - this has been going on for 45k miles.

Alternate for napkin - spanish moss - part adult diaper - fem sanitary pad
diaper material and fem pad material will hold a huge amount of oil and keep
off the tires and off the drive.