1984 BMW R80RT screeching noise when pulling in clutch.

[THESpencer]

Ok... new to BMW motorcycles. Have two Beemer cars and 5 different makes of motorcycles and work on each.
So I pick up this barn find and after hooking up to aux gas tank and firing her up I was overjoyed that she purred so nice.
Idled the bike for a few minutes, revving lightly till I felt oil was warm. Pulled in clutch lever and an ungodly screeching started screaming from the bike. released clutch lever and sound subsided 90% then was gone. Pulled in clutch lever again and same screeching noise. I put bike in gear and nothing happens. Wheel won't turn. I took bike off centerstand and turned it off. Put the bike in gear and it would roll easily like it was in neutral.
Has anyone encountered this?

[Rob]

You need to inspect/lube/ possibly replace the throwout bearing.

This is what your assy. looks like on RealOEM:
http://www.realoem.com/bmw/enUS/showpar ... Id=21_0086

The tip of the throwout rod that contacts the clutch spring needs to be inspected for wear*, and probably lubed as well. You can do all of this without removing the gearbox from the bike if you are good.
Removal is recommended.
The input shaft might need cleaning lubricating too.
When lubing the shaft, only put lube on the shaft, not the female teeth on the clutch. You probably already know about the dangers of flinging excess grease on your clutch surfaces.

* image from Duane's page

https://www.google.com/search?site=&sou ... m00Da-AZg4

Third link down is from Duane's page (a highly esteemed commoner here). It is not specifically relevant to your bike (older bikes), but a lot of the principles are the same.

[Rob]

And are you saying the bike rolls easily even when in a gear? If so, that cannot be good.
If the bike has been sitting for a while, you will probably want to remove the gearbox and bench test it, and at the same time examine the clutch and measure everything.

There are four screws ("bolts") holding the driveshaft to the output flange on the gearbox. The easiest way to loosen/tighten those is with the OEM 10x12 box spanner, and a thick glove.
You step on the rear brake pedal and pull the screws loose, and when you go to replace them (you may or may not want to use new), push down on that wrench with all you have (again, braking hard), and the torque should be correct.

[Rob]

I think you will find this video handy, even though this is a twin-shock and you have a mono-shock.

https://www.youtube.com/watch?v=9KErQYrYtzk

[THESpencer]

Thank you for all of the great information. I will be leaving (on another bike) saturday for a 3500 mile trip with my best friend. When I return I will start tearing down the R80RT and document my discoveries... will post when I start the tear down.
Spencer

1984 BMNW R80RT
1975 XS650 Bobber
1998 FXDWG
2001 Roadstar Bobber
1974 Honda Hawk Automatic ( experiment)