Decided to refurbish my 1975 R90S. Once I removed the transmission from the block it was apparent that either the rear main seal or oil pump cover gasket was leaking based upon the amount of built up gunk in the flywheel/clutch cavity.
After blocking the crankshaft as advised in one of Brook Reams postings I removed the clutch parts followed by the flywheel.
Once the flywheel was removed I notice that the rear thrust washer was not captured on its pins.
It was possible to rotate it in the area between its pins and the rear seal.
I reinstalled it on its pins but I am concerned as to whether or not the fact that it could come off its pins is customary or if I might have an issue.
Can anyone advise me on this scenario?
Also can anyone tell me who carries the newer version of the oil pump cover and o-ring?
Thanks for any advise.
Patrick
Normally, the flywheel bolts pull the flywheel and the back end of the crank together. This is what keeps the thrust shim in place. This is also why we want to block the crank from the front when we remove the flywheel. That way, the crank can not shift forward and allow the thrust shim to move. If you were able to get the shim back on its pins, great. However, when the crank is blocked, the thrust shim should be captured in place and unable to be moved.
That is the long -winded way of saying, there might be an issue.
Lately, I have been ordering parts from Tom Cutter's "Rubber Chicken Racing Garage", or MAX BMW.
former Airmarshal, IL.
After researching a diagram I realized why I was so confused by the help/answers that I’ve been given.
My concern was with the thrust washer “behind” the rear main bearing not the one in front.
I realize after removing the rear seal that this washer can be removed and reinstalled at will and it being free enough to come of its pins should not be an issue.
As I blocked the crank from the onset I will assume the thrust washer in front of the main has remained where it should.
Or at least that’s my prayer.
Thanks for the replies. I’ll try to be a little more specific with any further newbe/dumb questions.
Patrick
Hey Patrick, the thrust shim is inside the crank case. That is why it is a great big deal if it falls off the dogs (pins) that it rests on. You have to pull the crank to re-position it. That is why you must block the crank to keep the thrust shim captured in place.
The dumbest question is the one not asked. I am barking up the tree of 60 years old. I have owned my main Airhead ride for 30 years. I/we old guys know that these bikes can and may out live us. Those of us who derive pleasure from campaigning the machines also want to provide insight to the next generation of owners so that you young guys can keep the old line going. It's like a kind of immortality. nOOb questions,...bring 'em on.
former Airmarshal, IL.
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