Porsche Enthusiasts Club Forum

I replaced the transmission mount and the judder when changing down hard from 3rd to 2nd is still there but MUCH reduced. There doesn't seem to be any play in the torque tube...

I'll probably live with this one but I'm wondering....should I be bracing myself for a new clutch?

P.S. The old transmission mount looked pretty good to me (except for a bit of surface corrosion)...

This has been covered a few times recently on here.
Judder under those circumstances is usually down to the rubber center (damper) in the clutch wearing away or disintegrating.

Original clutch (Left), Modern Clutch (Right)



Unfortunately its a relatively expensive fix, the clutch kit is about £500.

I believe you can check the condition through the clutch inspection window, and by twisting the torque tube, if it turns there is wear.

Sometimes when the clutch disk centre on the original rubber items can fail but in a may that you can not easily twist the inner torque tube shaft, so it will seem secure and will not twist when you check it unless you apply a massive amount of torque to it.

Interesting. So, if I was to replace the clutch would I be going for an original part or an after-market...what are my options?

Thanks,

Barnaby

I would suggest aftermarket. The original is 'probably' more expensive - I've never asked for a price form porsche.

Back when I was looking this was the cheapest I found - http://www.promaxmotorsport.co.uk/Produ ... piece.aspx

Thanks for this.

Still don't understand why the the problem only occurs changing down from 3rd to 2nd! At no other time is the clutch a problem - pulling away, 4th-3rd, 2nd to Ist, crawling in traffic, no slip etc.

Until I can figure out what the problem might be I don't want to just throw money at it! I can imagine replacing the clutch, mounts etc only to to find out the clutch was fine and that it's something else...

A bit of a puzzle really... It could well be the higher level of force of engine braking in a third to second change.. Really had to tell remotely. If you get the chance to come over this way, pop in and I will take a look.

One other alternative.. About three or four years ago, we did have a 944 S2 which would stall during deceleration in second gear only.. We plugged it into the bosch hammer which reported a faulty hall sensor, which once changed, cured the problem, but we never did work out why when decelerating in 2nd gear, but it is usually similar to yours.

Thanks - I'm looking at when I can drop the car, leave it with you and continue on to Bristol for work. I'm away from Friday until the 30th but I'll be in touch then, and you can have a look at the steering. Cheers,

Barnaby

When the rubber clutch centre was going on my S2 3rd to 2nd down shifts were first to cause a judder. Its gradually got worse over time. Now 4th to 3rd does it too.

I suspect the transmission mounts also need changing as they will have worn much faster with the extra wear from juddering.

I found that If I heel and toe, or simply rev the engine between the downshifts it doesnt judder.

Yes, changed the mounts and reduced the problem but didn't eliminate it.

Tried heel and toe and nearly went into the back of a van. probably above my 'pay grade', as it were...

Still, I think the kids now believe me when I tell them I'll deliberately crash the car of the don't stop fighting.

Hi Barnaby,
I still have the same problem only very slight now -i can aggravate it as you said before by
not adjusting revs to change.
However mine had just had clutch changed - they no longer use the rubber clutch
with a standard Sachs one. it didnt do this before clutch change- it could be a really
violent shaking of the transmission and whole car if revs not adjusted.
Back to Garage and a reconditioned Torque tube was put in- I know as i collected
Torque tube from London- the reason given was the splines on the drive shaft were badly
worn and the new clutch sits in a different position on shaft. So all changed plus a
R.M.S.
Has reduced it by maybe 90% but still some transmission judder from 3rd to 2nd.
My indy [Porsche trained] nor i can explain it.
I agree a visit to Jon seems the only answer.
Sorry if i have hi jacked your thread but this is the first time i have seen this
problem mentioned.
But in my instance a new clutch seemed to start it not cure it.
really want to know what is causing it.
Cheers
Ron

Ok you guys,

What are your engine mounts like?

On an 8 valve car, you can tell if the engine mounts have begun to collapse, by looking at the lowest screw on the distributor cap, ideally it should be level with the top of the headlight bar, if it is bellow this, then the engine mounts are shot, which will mean the engine, torque tube and transmission can twist a few degrees. Enough to cause backlash.

Normally this also causes a vibration at idle through the steering, seat or gear lever.

The transmission mounts are only there to support the weight of the transmission and keep it in the right vertical plane, not stabilise it from twisting.

can anyone help?Mine is doing this and I am fed up with it!

New clutch centre sprung, new gearbox and engine mounts.

Car feels like the gearbox is about to fall out if just let out clutch changing down from 3rd to 2nd with giving it a really blip of throttle - which is fun but want it fixed.

This car in bits is now worth more than a new 911.