Sachs Clutch Judder in Reverse

[lagadmar]

I have just fitted a Sachs Stage 2 clutch to my 997 Turbo. I needed the upgraded clutch as the modified car was too powerful for the standard clutch which was 18,000 miles old.

Since installing the new clutch I have noticed a "judder" in reverse.

The clutch has done about 400 miles since installation and it seems to be getting better but still very noticable.

I had it checked over by the installer and he could find nothing.

Anyone got any thoughts? I have tried searching the forum.

Many thanks.

Marc

[Ozzie Osmond]

The clutch does not know which direction the car is being moved or what gear you are in as it always rotates in the same direction. So it could well be a gearbox or differential problem or a CV joint that is lumpy when reverse loaded.

[lagadmar]

Thanks Ozzie, I knew that the clutch would rotate in the same direction but I really appreciate the advice. I is weird that everything was fine then I replaced the clutch and it all went "Pete Tong".

I will give it some time to bed in and then get Porsche to take a look to see if it is what you suggest.

The car has only done 18,000 miles so hopefully it is nothing too major.

Cheers,

Marc

[Rich_W]

The key phrase is "uprated" It will have different characteristics to the normal version. The pressure plate springs will be heavier and less easy to modulate power as a result.

WHY O WHY do people fit uprated parts then complain they lose a little bit of comfort/quietness.

Edited by Rich_W on Saturday 19th June 11:29

[pits]

Ozzie Osmond said:

The clutch does not know which direction the car is being moved or what gear you are in as it always rotates in the same direction. So it could well be a gearbox or differential problem or a CV joint that is lumpy when reverse loaded.

So, the engine doesn't spin backwards then, who'd have known



that is a joke about engine spinning backwards

[snoopstah]

Is it a paddle clutch? I have a Sachs paddle clutch and it judders if you slip it too much (as you might if reversing slowly). As I understand it it's a characteristic of that type of clutch.

[lagadmar]

Hi, no it is a standard manual no sign of a problem before I changed the clutch. I had heard of this with the paddle box. Thanks for the reply.

Marc

[snoopstah]

lagadmar said:

Hi, no it is a standard manual no sign of a problem before I changed the clutch. I had heard of this with the paddle box. Thanks for the reply.

A paddle clutch is a type of clutch used on a manual car. As I understand it, it uses small 'paddles' to transfer the drive rather than the larger area used by a standard full-face clutch. This increases the pressure and allows the clutch to cope with the higher torque a tuned engine delivers.

It has no relation to a paddle gearbox. My car is a standard manual and has a paddle clutch fitted to cope with the extra torque

Paddle clutches are slightly specialised on road cars as they are harder to use -- they generally have a very small bite distance, and are often described as an on/off switch, so you may not have one -- but if you did, the judder would be expected.

[lagadmar]

Doh! Sorry no I see what you mean. No, sachs do a paddle but the stage 2 isn't paddle at least I don't think so based on your description. Sorry for for being dumb.

Thanks,

Marc

[Ozzie Osmond]

lagadmar said:

No, sachs do a paddle but the stage 2 isn't paddle at least I don't think so based on your description.

I think that's right.

At 18,000 miles there shouldn't be too much wear in the driveline but, on the other hand, if your driving style demands this type of clutch there could well be "accelerated wear"! The only other thing I can think of is whether the different gear ratio of reverse could make a difference - but this doesn't seem likely to me.