Throwout bearing distance from clutch plate

[Fingolfin]

I hope that makes sense in British terminology! Anyway, what I'm talking about are the carbon bearing that actuates the clutch, and the sprung ring-shaped plate that it contacts.

I put the gearbox back in Mog the other day, and connected the clutch linkage; the system works smoothly, with the pedal depressing and returning nicely and the gears changing without much ado. However, something is radically different from when it was in before, and I can't figure out what; the symptom is, with the long metal rod in, the throwout bearing rides on the pressure plate, even with the adjustment nuts right at the end of the rod. Without the rod in, there's a tiny tiny distance:[frame][/frame] Before, the nuts were about halfway up the threads on the rod, and the clutch disengaged (though I never watched it inside the bellhousing, like I did today). The only thing that has been changed in the system is the clutch pedal; the throwout bearing was never disturbed from its mounts, and, except for the pedal and all the worn bushings, all the old parts are in use.

I could make a new, longer rod, but that seems like a bodge rather than a solution. Has anyone got any idea what the problem is?

[simmitc]

Is it possible that the incorrect lever has been fitted at some time (early and late are different) and the old pedal compensated for that? If the angle of the new pedal the same as the old, or is the relationship between the pedal and the rod mounting slightly different? Does the freeplay adjust correctly?

[bmcecosse]

Looking in there - the pressure pad on the clutch assembly doesn't look to be square to the rest of the clutch. When you turn the engine - does it wobble ?? Bit like a swash plate on a hydraulic pump...... I suggest it has been knocked out of place won assembly. Engine out to correct it i'm afraid.....

[Fingolfin]

Sim, if you mean the fork that holds the throwout bearing, I'm quite confident it's correct -- ESM shows that the 1098cc fork has no curve but the 948cc does, and my fork has a curve (I have a 948cc). There is no free play at all, and no room on the rod to give it free play. The new pedal was somewhat different from the old, but (having just checked) I can say confidently that the "shoulders" around the inboard threads are at the same angles on both new and old pedals.
I can't turn the engine yet, the car isn't assembled enough; but if the pressure plate is in fact cockeyed, how do I correct that? Surely it's not so simple as just pushing it back into the correct position? The bearing lays flat against the pressure pad when the clutch is actuated, if that matters.

[mike.perry]

Have you fitted a 1098 or 948 clutch release bearing, carbon thrust bearing, throwout bearing?
A drop of oil on the pivots helps.

[Fingolfin]

I have fitted nothing at all -- the bearing is precisely the same as the one that was in Mog before. It still had (what I thought to be) a good amount of carbon on it, so I just left it. The clutch worked quite well when it was drivable before.
I'll make a point to put some oil on (and perhaps to replace the bearing...) if I have to get it out again.

[bmcecosse]

Why can you not turn the engine ??? Just put a spanner on the front pulley bolt. It definitely looks cockeye (and v rusty??) You would need to inspect it to see why it's not level - very possibly the spring on the other side has been knocked out of position. I suppose it may be fixable through that hole if you can see the problem....... Turn it to see!

[Fingolfin]

Oh, whoops, problematic terminology -- I meant I can't fire the engine. It turns all right...I'm not sure why I said that. So I shall turn it and report back.

[bmcecosse]

Get someone to turn it slowly while you watch what's going on inside there.

[Fingolfin]

Well, it was turned (by dad), and I was watching. The pressure pad was a bit cockeyed (perhaps 5mm wobble), and I imagine it must be sitting several cm too far back, because the throwout bearing itself has very little room to move forward or backward. I tried to lever on the pressure pad with a long screwdriver, and it moved a bit, but I wasn't sure what I should have been doing...any suggestions? I imagine the engine must be withdrawn now.

[kennatt]

from the photo ,I think BMs right ,the pressure plate has been knocked out of place as you fitted the gear box,easy to do if engine was still in the car on refitting,looks like engine out I'm afraid to say, Might be able to force it back into place but would you want to risk driving it afterwards

[bmcecosse]

Pop the engine....

[Fingolfin]

Will do. Dad's of the opinion that we should repair the thing and reassemble engine and gearbox outside the car, replacing the whole unit as one, to avoid damaging it again -- is this the right way to go? More importantly, how do I fix it once it's out? Perhaps it will become apparent when I can see it easily...

[mike.perry]

First identify the problem, then find a solution.
If it is a broken spring it will be a new pressure plate

[kennatt]

Tempting as it is to take the box or engine out after separation in the vehicle, there is always a chance ,of causing this problem on refitting,Its not too bad to lift the whole lot out or refit the whole as one and I suppose once bitten,like you,twice shy as they say.You still have to be careful fitting them outside the car as well.

[bmcecosse]

If you have the lifting gear - by all means do it that way.

[Fingolfin]

Well, we got the engine and gearbox out as one unit to avoid disturbing the clutch further. Have a look and see if you see anything wrong.[frame][/frame][frame][/frame][frame][/frame][frame][/frame]The pressure ring is 23mm from the base plate at the widest (with a variation of only 1mm). I have another 948cc in my shed, and the same measurement on it is 21mm, so that's a difference of 2mm; however, the difference on the actuating rod between the previous and current adjustments of the domed nut is 13mm. Where's my other 11mm?

What else should I be looking for?

(Measurements revised due to it having been late when they were first written.)

[kennatt]

well the spring on the left side on the third photo appears to be sitting lower than the other side causing the thrust ring to be tilted down at the left, change the pressure plate for a new or known good one .

[bmcecosse]

It's obviously off to one side - so it will vibrate like mad. You can try adjusting it - I think detailed in the Manual, but not something I have ever done. 21 cm seems an awful lot.......

[moggydriver62]

Hi Fin. You have gone this far, take the pressure cover off and check the linings on the disc.