Porsche Enthusiasts Club Forum

Hi,

Anyone experienced a violent judder when changing down from 3rd to 2nd, when using engine braking and driving in - shall we say - a 'spirited' manner?

It's manageable, and doesn't happen with any other changes, up or down. But it really is quite vibey when it happens.

Incidentally, the car runs very smoothly, is up-to-date with belts and services, and 75k miles on the clock. But it new to me and I'm finding my way with it.

Cheers folks!

Barnaby

1991 944 S2

Sounds like it could be the rubber doughnut in the clutch, but I thought they'd done away with that in the S2. Also have you checked for backlash in the drive shafts?

It happens to my car in all gears. I've put it down to driveshaft wear and that clutch doughnut. I anticipate the behaviour and try to avoid it where possible.

Check engine mounts, transmission mount and free play in the torque tube which indicates a breaking up clutch centre (tested with the engine off, car in neutral and no one touching the clutch)

Hi Barnaby and all,
I was just about to ask the same question on forum- exactly same symptoms .
Has just had clutch replaced with sachs one not rubber, belts and rollers done at same time.
it was taken apart again and wear found on drive shaft splines new clutch uses a slightly
different section so it was explained the wear would cause this vibration- it did not do this with rubber
clutch. So a reconditioned torque tube was fitted with good splines and new bearings- main rear seal done at same time.
Problem is it is still doing it -nowhere near as badly. Both indi and i scratching heads.
Jon- i believe engine and gearbox mounts are good and rest as above. I have to try to get it to do this ie change from
3rd to 2nd without adjusting revs it wont do it if you blip throttle on change and as Barnaby says a bit spiritidly and using
gear for engine braking.
Any one any suggestions.
Cheers
Ron

I always rev-match every gear change. I like the reassurance of less wear on the syncros and clutch, plus I enjoy the technical side of the (slightly unnecessary) skill!

Hi Ron,
Interesting that you changed the clutch yet this only reduced the problem...
Jon's advice (as always) is valuable. I'm going to check the engine mounts, transmission mount and free play in the torque tube. I'm hoping these are things I can do myself and make a judgment on the work that needs to be done, as I'm in Falmouth without a nearby Porsche specialist.
Cheers,
Barnaby

Are the mounts easy to access and what should I be looking for? I'm guessing that replacement is a big job?

And what am I looking for regards free play in the torque-tube?

Many thanks as always,

Barnaby

Hi Barnaby.
Sorry if i wasnt clear - it didnt vibrate until clutch changed to conventional plate one-with new release pin and bearings.
so it was stripped down again and worn splines found- the new clutch uses a different part of the shaft to connect to which
coincided with the most worn bit of splines. Replaced with a reconditioned torque tube with good splines and new bearings.
Vibration still present it is much harder to make it do it now but can still be quite a judder if provoked or you can just feel
slight vibration through gear stick if gentler.
Of course normally i balance revs when changing gear - but i still need to know what is causing problem.
Agree Jon is spot on usually - i will check engine and gearbox mounts-although last owner an engineer and
perfectionist had i believe replaced these less than 12K ago.
Anyone any other thoughts as i dont want to have to drop axle strip it down a third time- or my indie anyway.
Cheers
Ron

Old thread but this get resolved as having the same problem and very frustrated with it....

Thanks!