Clutch pedal vibration

[mjb]

Half way through my drive to work this morning, my clutch pedal started vibrating. When I got to work I found the car making a knocking while trying to reverse (mildly uphill) into the parking spot. "trying" is the word there - it wasn't easy!

The vibration happens at idle in neutral - you can feel it without pushing the pedal.
The vibration gets faster with engine revs, even in neutral.
The vibration gets stronger when the car's at bite point.
The vibration isn't affected by speed
Opened the bonnet and the engine wasn't moving around more than I'd expect

I've been suspecting my bottom engine mount is shot for a while now due to mild bite point judder, think it's finally died? The top and gearbox mounts are new.

[omega]

might be the engine mount, try sticking a jack underneth and see how much you can lift it
BUT
i think its new clutch time
as you say difficult to reverse uphill do you mean lots of revs and no movement?

[mjb]

i think its new clutch time

I changed the clutch a couple of months ago

as you say difficult to reverse uphill do you mean lots of revs and no movement?

No I mean it's virtually impossible to control as the vibration is excessive at bite point

[mjb]

Think I'll see if I can get someone to put it on bite for me so I can see if anything's going on with the mounts. Then I'll order a lower mount and clutch release bearing from the stealers while praying I don't have to spend the next week riding a bike to work and killing my back in the evenings trying to fit the bearing

EDIT: Wonder if it could be the upper release fork holder has popped out... I remember I broke one of its clips, but it was that tight a fit (and it's got gravity helping it) I didn't worry about it

[mjb]

It's not the fork sleeve and it's not the engine mount. There's definitely a knocking sound coming from the bell housing area.

F**K!

[steve_earwig]

Fook indeed, got my fingers crossed it's not something disastrous.

[mjb]

I think it's already pretty bad considering I've got to dismantle the suspension, drop the subframe and take the gearbox out again. Going to be a scary drive home tonight Going to be stuffed if I can't drive it to my garage though - my driveway's way too steep to push the car up

There's 3 possibilities tonight:
1) I get home
2) The clutch breaks and I can't disengage it
3) The clutch breaks and rips itself (and maybe the bell housing) apart

[steve_earwig]

I guess it's the usual advice - take it easy, keep the revs down, try not to change gear too often. It's a shame these ML5Ts don't seem willing to change gear without the clutch.

I've had release bearings scream, shriek, rattle, I even had one seize and saw its way through the diaphragm spring but I never had one vibrate.

[Welly]

Holy sheet, can't you get it recovered back to your place?

[Captain Jack]

Oh dear, Matt. Not another clutch problem. Hope you get it sorted quickly, painlessly and, most importantly, cheaply!

[teamster1975]

Fingers crossed Matt
If you can I'd be tempted to do as Welly suggested & get a tow home.

[Welly]

At work here we use a garage with a recovery service and they charge about £35.00 for an in-town pick up and drop off, surely Stoke's got something similar? might save you a lot of other costs? you won't even have to start the engine

[mjb]

Made it home and into my garage ok - only went over 1500rpm once, and that was while doing a clutchless downshift!

Interesting discovery: The brake pedal's vibrating too, albeit to a much smaller degree and only when pressure's put on it. Hmmm. Think the first thing I think I'm going to do is take the clutch slave cylinder out and have a feel of the release fork. It should be blatantly obvious if that's going nuts when the engine's idling

I'm still suspicious of the lower mount though - I know from experience that massive judder inside isn't necessarily visible outside

Wonder if I can fit a bottom mount from an ES9J4S (with the replaceable bush) from a breakers yard and just slap a new bush in it instead of buying a new one at £90 ish... The subframe bracket's the same, as are the driveshafts, but there's no crossover period between the engines and mounts, so the holes may be in different places

[mjb]

I think I'm suffering from troubleshooting here

Earlier, I got a guy at work to take it to near-stall in 4th while I looked at the engine and saw nothing. Here in my garage, I rigged up a large mirror on a couple of axle stands and looked through the gap in the open bonnet. Let the clutch out gently in 4th and you see nothing but the engine slowly rotating towards the radiator (only noticeable when you plummet the clutch back in and it springs back)

Put it in 1st or worse reverse, and all hell breaks loose, as does rapidly letting out the clutch in other gears. Holding the footbrake while letting the clutch out sloooowly results in just a gentle engine twisting though

There's also a new knocking from sound the rear and belt areas at idle (can't test at bite) which disappears at higher revs.

I think all this points to a dead bottom mount. Unfortunately I can't think of an easy one-person way to look at it at bite point so unless someone can suggest a better course of action, I think I'm going to go and blindly replace it on the risky assumption that I'm right.

The only symptom I can't match to a duff mount is the rattling from the bell housing, unless the vibration's causing the release bearing to rattle about the pressure plate forks...

[steve_earwig]

Lordy No rubber left in the mounting so it's passing engine vibrations on to the subframe near where the pedal pivots are?