Never to old to learn

[papamantra]

Hi,

My car has recently been juddering whilst changing down from 3rd to 2nd sometimes its quite violent.

So I let my friend who is a test driver have a drive and the car performed beautifully, smooth gear changes no judder etc. His comments were the car drove close to when he first did some testing.

I got back into the car after he had gone and went for a spin and low and behold the juddering returned.

I then took my brain out of modern driving and went back to matching revs on down shift etc and the car seems 100 times better.

I think I am going to have to teach myself to drive again with light feet or is the juddering a symptom of something about to break?

Ant

 

[TTM]

Hi,

Are you still running the original rubber-center clutch disc?

 

[GlennS]

I does sound like one of the rubber centred clutches coming to the end of its lifespan.

 

[Lowtimer]

It does sound like a rubber-centre clutch on the way out, but that said, why would you ever drive a manual car without rev-matching? It's terribly hard on the machinery not to do it, and doing it is a bit part of the reason of why analogue cars are fun and digital cars are boring.

 

[TTM]

It must be said that it will be a pain to attempt any proper toe-and-toeing if the height of the brake pedal has not been reduced, and most S2s I have been in seem to be set from the factory to prevent any kind of toe-and-toeing.
It was a revelation when I finally lowered the biting point... after 10 years of ownership... [8|]

 

[bumperblue]

Exact same symptoms on mine.

Replaced rubber centred clutch @80k miles so was pretty gone though apparently still had some meat left the rubber was jusr really tired.

All nice and smooth now.

The juddering can be quite interesting when you want to change down quickly coming into a roundabout, spoils the fun.

Ian

 

[papamantra]

It could be the clutch.

According to the paperwork I have it was replaced 15k ago but then again that was 6 years still seems a bit early to be going again.

I will have to dig out the paperwork and check.

I agree with Ian it can really spoil things when you want to drive quickly, easy to stop happening if you slow down way before the junction.

 

[bmnelsc]

It is possible - tho highly unlikely - that the clutch was replaced with a rubber centered one - who knows what new old stock was available when it was done. Could also be the clutch disc binding up on the input shaft spline due to a lack of lubrication.

I've just replaced the clutch in my S2 (60K miles) even tho the external wear measurement showed the disc was near new (20mm vs new measurement of 18mm - wear limit 34mm). My symptom was noisy release bearing and sticky clutch action (binding on the guide tube). Reviewing the parts that came out - the spring center disc was indeed near new but the grease in the release bearing was thick, old and hard. The bearing felt OK at hand speed but was definitely noisy in operation. It appears that when the clutch was changed - not everything was changed - possibly only the disc. You might be in the same boat - "recent" work but not a proper job. A new guide tube and pilot bearing cost very little compared to the disc, pressure plate and release bearing so it is truly a false economy to not renew them while you are in there.

FYI - the current SACHS catalog lists one clutch kit for the 944NA which is a lot cheaper than the old ones. The new disc has four springs arranged around the disc hub - each a large spring with a smaller spring internal to it rather than the previous style of three large springs and three smaller springs arranged around the hub. Its nice and smooth with low effort.

 

[bmnelsc]

Hmmm - my S2 pedals seem to be placed properly - very easy to roll the foot for a throttle blip. I'm not heel/toe wizard mind you but now that my clutch works properly (see above) I expect to get a lot better.

 

[papamantra]

Hi,

Just put the car on the ramp and noticed that there is quite a lot of lateral movement on the transmission.

If I wobble the exhaust the gearbox seems to swing quite a lot so I imagine that is moving the engine mounts.

It looks like the transmission mount is bad and needs to be replaced or could it be the engine mounts that are causing the lateral movement?

I am not sure if the transmission mount is just a hanger and the movement comes from bad engine mounts or even if there should be lateral movement.

Could this be causing the judder?

Ant

 

[944 man]

The transaxle mount (single on series two cars) would be the first thing that I suspected.

 

[zcacogp]

ORIGINAL: papamantra
Just put the car on the ramp and noticed that there is quite a lot of lateral movement on the transmission.

There always is quite a lot of lateral movement on the gearbox in a 944; the hanger just hangs the gearbox from a single point, and there is precious little bracing for it. However if you think about it's operation then there is no sideways force that does not have an opposite force applied (i.e the drive is through a torque tube), hence the movement is fine. The only exception to this is when cornering, although the forces applied then are small relative to the forces exerted by the transmission.


Oli.

 

[George Elliott]

Agree everything suggested above, and I suspect your test driver buddy has effectively driven round the judder - sub-consciously as he possibly has an affinity with things mechanical. You are not driving around it and most people don't, it can also be a pain in everyday use to have to drive around it.

I have seen a similar issue described by Bruce originating with the spline being lightly corroded (due to a weep on the heater valve above the bell housing) and when the car was parked for a couple of days it would be juddery again. After 2 days constant use in traffic it would be free again and the judder would go.
Fixed the weep and sorted the clutch action.
At the time, I could "clean" the corrosion, just a few thou of rust was enough to make it judder, by operating the clutch about 20 times before driving. The problem would virtually disappear then.

The transaxle mount is not very rigid, but as said it does not have to be. Saying that, I too would start here as it is 99% sure to be the original.

Pedals are all too high in modern cars, I think since Audi had the run-away issue in the States in the 1980's with Drivers confusing Brake / Accelerator.

There is a satisfaction in well honed analogue cars. I got a 208 Pug as a hire car this week, and it is difficult to believe the Company who gave us the 205 thirty years ago, would today make such a vile device.

Good luck with it
George
944t

 

[Neil Haughey]

Simon is right, trans mount is weak anyway and at this age they will almost certainly be shot on any 944. Best and easiest thing to do is take it off and squirt sealent into the thing, fill up all the gaps and make it nice and tight again.

On my race car I have a traditional peddle screwed onto a nut which EMC weld onto the throttle arm, the throttle arm is also bent over to make it easier for me to heel and toe but I also mounted the pedal right over to the left (the organ peddle went in the bin). Its very easy to catch both peddles if wearing big shoes but as its a track car only this is fine as its only really ever driven wearing race boots. I could heel and toe in a stock 944 but it means bending the ankle over at a pretty extreme angle, I still have to put my leg in a pretty uncomfortable position but when concentrating on track you just don't notice things like that and it all sorts of works. You only need a tiny amount of throttle for it to do the job anyway.

 

[papamantra]

Hi

Yep it was the trans mount which came off the car in 3 bits!

I decided to get a new one which was expensive but well worth it as the car is back to being silky smooth.

Didn't fancy trying the silicon idea as it was far to gone, in fact it had very nearly failed completely just held up by a chunk of pinched rubber.

Ant

 

[amrbose14]

I'm not saying I'm good at it, but heel and toe has always seemed much easier in my 944 than any other car I've owned or tried it in. Dodgy clutch aside it only really matters when braking near the limit to avoid traction problems. In those conditions you are fairly firmly on the brake. In light braking you are having to do a difficult balance between throttle and brake pressure. It does sound good, but you look a bit of a prat if you suddenly stop 10 feet before the junction. Luckily I have maxed out on prat incidences... so nothing to lose!

Chris
87 220T.

 

[ChasR]

ORIGINAL: Lowtimer

It does sound like a rubber-centre clutch on the way out, but that said, why would you ever drive a manual car without rev-matching? It's terribly hard on the machinery not to do it, and doing it is a bit part of the reason of why analogue cars are fun and digital cars are boring.

Many of my friends with an interest in cars drive the same way. All I say is that before I fitted the Group N engine mounts to the 205 it was known when my friend changed gear and how the car juddered etc. (two other people have a share in it).

With the above in mind I would also be looking at 'box mounts and possibly even engine. My S2 used to judder slightly with a new Sachs clutch (of the solid centre variety) but the Turbo is far smoother. The latter does seem to have new genuine mounts in place however (engine, gearbox etc.).