D4 main clutch release bearing vibrating

Hi Timothy,
for your lever to be vibrating like that, the throwout flange is likely wobbling. First thing I'd check for is whether the throwout flange is running true. If it isn't, then check whether the whole clutch mechanism is running true - you may have a collapsed pilot bearing (and possibly a shot transmission input bearing).
Cheers,
Neil.

I would also be looking in to a worn/misaligned coupling.

I agree, I had a similar problem with my D4 7J I recently restored and found the two pieces of the coupling were not aligned properly which made the clutch shake, there must not be any gap between the 2 pieces.
regards
Mike

[quote="Mike Meyer"]I agree, I had a similar problem with my D4 7J I recently restored and found the two pieces of the coupling were not aligned properly which made the clutch shake, there must not be any gap between the 2 pieces.
regards
Mike[/quote]

There doesn't seem to be any gap between the 2 pieces of the coupling.

I did try (with the clutch disengaged) to lift the input shaft and clutch up , and it did move a little bit (on the spigot bearing end)

With it assembled, the clutch shaft seems to be be running true, but will have to remove the release bearing housing to see if the flange is running true.

If I just engage the clutch to turn very slowly, the clutch fork and outer bearing give a sort of 'kick' back once every revolution.

Thanks for the reply's,

Tim.

Could the trouble be that one linkage sets from the throwout bearing to the pressure plate is missing, bent , or pins worn out thus creating a off center action of the bearing?

Several years ago I ran into a similar problem with a D4 7U. What I found was the lower bolt going into the trunnion had dropped out. To access that, remove the lower side cover from the flywheel housing as well as the flywheel drain plug. If that's the case, you'll have to get the bolt started and then put an appropriate size socket on it by going thru the side cover. Then poke an extension up through the drain plug hole and into the socket (the socket itself will NOT fit through the drain plug hole so that's why you have to put it in through the side access hole), tighten the bolt and bend the lockwasher onto one flat.

If you have a belly pan, this can turn into a real fun job. Trust me, been there and done that😆