Clutch judder

[stew72]

Ok, 1993 M40 engine 318i, 88k from new, pretty sure still on original clutch. I get a judder more often than not when pulling away, but not every time, and can drive around it in first with a few revs, but quite frankly reversing can be embarrassing (loud knocking too!). The car had a leaky clutch slave cylinder when I bought it and I did attribute it to that, but I've now done 6k and I'd have thought any contamination on the friction plate would have burnt away by now.

So before I decide to change the clutch is there anything else it could be? Could it be a mounting? or possibly propshaft related? I may have access to a workshop with a 2 post lift in a couple of weeks time so could do with a few pointers to begin investigating.

Any suggestions and guidance welcome.

[maggspower]

It is probably the clutch, but I would be checking the prop bearing, g/box mounts, and the guibo between the g/box and prop. Although all of these get worse with speed or if you plant the throttle in any gear.

Expect the worst though.

[stew72]

It is probably the clutch, but I would be checking the prop bearing, g/box mounts, and the guibo between the g/box and prop. Although all of these get worse with speed or if you plant the throttle in any gear.

Expect the worst though.

Cheers Byron. Once rolling, everything is nice and smooth, theres no knocks when lifting off and reapplying the throttle so in reasonably confident that its not mountings but will check.

How do I check the guibo, just visual for damage an lever with a pry bar? And where the prop bearing and how do I check?

[maggspower]

It is probably the clutch, but I would be checking the prop bearing, g/box mounts, and the guibo between the g/box and prop. Although all of these get worse with speed or if you plant the throttle in any gear.

Expect the worst though.

Cheers Byron. Once rolling, everything is nice and smooth, theres no knocks when lifting off and reapplying the throttle so in reasonably confident that its not mountings but will check.

How do I check the guibo, just visual for damage an lever with a pry bar? And where the prop bearing and how do I check?

Visual check is usually all thats needed. You can give it a wiggle though

The prop bearing is up near the center U/J. Grab the prop 2 hands and try to move this, they are constructed of a bearing, a diaphragm which holds it an a yolk housing. It is the rubber diaphragm that fails

If you are down there changing the clutch, renew these bits too as a matter of course IMO. Remember the guibo is sided, and the center bearing needs to be preloaded.

HTH