1975 R90S New clutch install

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skychs
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Joined: Fri Nov 25, 2016 2:12 pm

1975 R90S New clutch install

Post by skychs »

1975 R90S

I ordered a new clutch kit from Bob's BMW. It comes with just about everything I need except the flywheel. Since most of it is new do I still need to send it off to get balanced? If so ..... just the flywheel or everything as a package?
Thanks
Chuck

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schrader7032
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Joined: Fri Oct 27, 2006 3:00 am

I wouldn't put much priority

Post by schrader7032 »

I wouldn't put much priority in balancing the clutch pieces. They're manufactured better today to closer tolerances. And removing the flywheel is tricky...needs a lot of torque and most importantly, you must, must block the crankshaft in the front engine cover to keep the shaft from moving. If it moves, you're facing an engine tear down. Once you have the flywheel off, you should really change out the oil pump cover o-ring as well and the rear main seal. Unless you have evidence of leaking from the rear of the engine, I'd be inclined to leave it alone.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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skychs
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Joined: Fri Nov 25, 2016 2:12 pm

clutch kit

Post by skychs »

Thanks Kurt
Sorry .... I should have said where Im at in the rebuild. Everything is out including the flywheel. The rear main seal and oil pump 0-ring have been changed. The crankshaft was blocked with a 2X4. Id post some photos but my iPhone images are tooooo large to include.

At this point Im just waiting on the parts to come in. The bike was running smooth when I took it apart. The flywheel is the only "used" part going back in and it is marked. I would think the new parts would not need to be balance, that's why I asked. My local BMW mechanic recommends I send it all off to get balanced.
Chuck

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schrader7032
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Joined: Fri Oct 27, 2006 3:00 am

Your call I guess. It's only

Post by schrader7032 »

Your call I guess. It's only time and money. You might always be kicking yourself if there's any doubt when it's all together. If you just were replacing the clutch pack, I'd say forget it. But if the flywheel is already out, then it's easy to do...for peace of mind.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Jim D 5112
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Joined: Fri Oct 27, 2006 3:00 am

Balance

Post by Jim D 5112 »

I just put one back together with the old parts and I know that they were not balanced before. Dose the flywheel have holes drilled in from before around the edge from balancing? Did the factory balance them?

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skychs
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flywheel

Post by skychs »

I just put one back together with the old parts and I know that they were not balanced before. Dose the flywheel have holes drilled in from before around the edge from balancing? Did the factory balance them?

I believe the flywheel is original without any holes or modifications. All the other parts are brand new from Bob's BMW.

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skychs
Posts: 359
Joined: Fri Nov 25, 2016 2:12 pm

Update

Post by skychs »

I finally finished the clutch assembly.

Everything went in without a problem. It started right up and she ran like a charm today. No unusual vibrations or sounds. No smells and most important ..... no slipping. It took a couple adjustment to set the clutch lever but Im very happy. With sunny weather predicted for tomorrow I plan to take it out again to push it a little more.

I did not have the clutch assembly balanced. I reused the original flywheel with all new OEM parts from Bobs BMW. I will keep you posted if anything changes. Thanks again for all the input.
chuck


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RickR90s
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clutch

Post by RickR90s »

I've replaced many of them and with the 11 lb. original flywheel, balancing of the component's wasn't necessary. On one R90s with a lightened flywheel, I sent the whole assy. (flywheel and all new clutch components) out for balancing.

RickR90s

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