Clutch

[Tony S]

I have just changed the gear box on my '30 RK and have something tapping the clutch mechanism so the pedal vibrates. This disappears when I disengage the clutch. Is there some adjustment that I have got wrong or does it look like an engine out again scenario. Welcome any help. Thanks.

[bob46320]

Did you do anything to the clutch? If you did, it sounds like the clutch fingers that bear on the release bearing are not all perpendicular to the bearing. Yes, it would be engine out. If the gearbox was a straight swap, I have no idea.
BobH

[Tony S]

Did you do anything to the clutch? If you did, it sounds like the clutch fingers that bear on the release bearing are not all perpendicular to the bearing. Yes,  it would be engine out. If the gearbox was a straight swap, I have no idea.
BobH

Thanks for that Bob. no, straight swap.

[Ian Williams]

I agree with Bob, one possibility is if the face of the release bearing was worn and you have assembled it with different fingers bearing in the slots it could upset their apparent heights. In an ideal world all three levers should be exactly the same height and the face of the bearing housing flat, they are often badly worn, I build the housing up and re-machine the face, others I know fit a ring inside the housing for the levers to bear against.

[Hedd Jones]

Sounds to me like the fingers are catching the taper pins on the clutch shaft on the gearbox.

Can happen for two reasons, the fingers are set wrong (usually too far in), with a very lw pedal. Or if the spring on the pedal is fubar allowing the pedal to come back too far.

I cant say Ive ever had problems because of wear in the fingers, the pivots or the slots in the bearing. I simply set the fingers so that when you put a straight edge across the crankcase you can just put a 1/4 spacer between the straight edge and the finger. Put some pressure on the finger with your thumb to take all the slack out. Set all three the same and your good to go. 

Similarly Ive never seen a bearing that has worn all the way through, at the end of the day thry are usually equally worn at all three points. With the fingers set as above an unworn  bearing will have very little play in the pedal before everything is touching and a high pedal. A slightly more worn bearing will have another 1/4 play at the pedal. 

So its engine out I'm afraid