997.2 GT3 Clutch Wear Symptoms?
Discussion
Guys,
My clutch when reversing shudders quite badly, yet when going forward it has no shudder at all. In fact you can take off on flat ground without pressing the accelerator and the pedal has a reasonably low bite point. It shows no sign of slip when accelerating either. Now it could be that the springs in the clutch plate have lost their tension causing the shudder in reverse, as I have seen this before.
Does anybody have any experience on this? The dealer thinks my clutch is worn badly, but I really have my doubts. They say that that is why my pedal is so heavy (feels normal to me). The bite point is reasonably low in the travel and I don't think these things have a self adjusting clutch, so if it was wearing you'd imagine the bite point would be reasonably high in the travel.
I also note that on rare occasions the resistance in the depression of the clutch pedal changes, so it is linear 2/3 of the way down, but then goes softer, almost like you are pushing the cup in the master cylinder inside out. However it doesn't do it all the time.
Any ideas
My clutch when reversing shudders quite badly, yet when going forward it has no shudder at all. In fact you can take off on flat ground without pressing the accelerator and the pedal has a reasonably low bite point. It shows no sign of slip when accelerating either. Now it could be that the springs in the clutch plate have lost their tension causing the shudder in reverse, as I have seen this before.
Does anybody have any experience on this? The dealer thinks my clutch is worn badly, but I really have my doubts. They say that that is why my pedal is so heavy (feels normal to me). The bite point is reasonably low in the travel and I don't think these things have a self adjusting clutch, so if it was wearing you'd imagine the bite point would be reasonably high in the travel.
I also note that on rare occasions the resistance in the depression of the clutch pedal changes, so it is linear 2/3 of the way down, but then goes softer, almost like you are pushing the cup in the master cylinder inside out. However it doesn't do it all the time.
Any ideas
I had a very similar experience with a 997.1 GT3. Judder in reverse only. At first I thought it may be something to do with the diff but just lived with it. I had the clutch inspected during one of many RMS fixes and was told it wasn't unduly worn but decided to change it as it was the most economical opportunity. This did fix the issue. Weight of the pedal improved and the bite point was noticeably lower however wether the clutch was in danger of immanent destruction at that point remains unknown. Id suggest drive another car if poss and see if yours really is "normal"
The inside out feeling you describe happened to me as well but on the new clutch....just before it lunched itself at less than 1k miles.
The inside out feeling you describe happened to me as well but on the new clutch....just before it lunched itself at less than 1k miles.
After feeling the pedal of some other cars, I have determined that my pedal is too heavy plus the bushes in the clutch fork appear to have dried out and squeaks when hot. So I have ordered all the parts, in fact everything in the bell housing. You don't need to replace everything, but it was all pretty cheap so I've bought the lot as per the EPC screenshots.
The car goes in on Monday, so I take photos of the used parts and report back how it feels.
The car goes in on Monday, so I take photos of the used parts and report back how it feels.
thegoose said:
Doesn't this car have a dual mass flywheel? You need to get that checked for the deflection being within tolerance once everything's apart, and be prepared for a potential delay whilst you source one before everything can be reassembled.
Yes it does have a DMFW. The dealer will check it and I am hoping that I don't need it. Porsche don't make it a mandatory item for replacement like BMW. I spoke to a guy who recently had his changed and a replacement wasn't necessary. However I have my fingers crossed.So I dropped the car in today at 08:00 and got a call just after lunch to go and look at it. Basically what they found was that the clutch plate still had a few mm left before it reached the rivets and was better on one side than the other, generally ok. We didn't think it would have been giving an issue.
The pressure plate was badly scored:
The flywheel showed the biggest problem. It too was badly scored, not so much from blue heat, just heavily scored.
The dual mass flywheel is meant to have ~8mm turning slack to either side of the yellow dots when lined up:
Mine was within tolerance one way with about 7mm, but the other way was about 25mm + !
Thus the flywheel is buggered. The tech said that the shudder would have been occuring because of the flywheel largely being out of tolerance, but also because of the scoring to the surfaces either side of the clutch plate, basically it didn't stand a chance.
So as I was hoping not to change the flywheel I hadn't ordered it, now I have to wait a week for it to arrive and the parts now cost me double what I was hoping to spend because of the flywheel cost.
The input shaft looked ok, I didn't look at the release bearing, but I am changing all of the clutch release mechanism in there anyway.
Now I just have to wait for the flywheel to arrive, so I won't get the car back until mid-late next week.
As I have it all out we are going to change the rear main at the same time, even though it isn't leaking. While we are there it would be silly not too, just in case.
The pressure plate was badly scored:
The flywheel showed the biggest problem. It too was badly scored, not so much from blue heat, just heavily scored.
The dual mass flywheel is meant to have ~8mm turning slack to either side of the yellow dots when lined up:
Mine was within tolerance one way with about 7mm, but the other way was about 25mm + !
Thus the flywheel is buggered. The tech said that the shudder would have been occuring because of the flywheel largely being out of tolerance, but also because of the scoring to the surfaces either side of the clutch plate, basically it didn't stand a chance.
So as I was hoping not to change the flywheel I hadn't ordered it, now I have to wait a week for it to arrive and the parts now cost me double what I was hoping to spend because of the flywheel cost.
The input shaft looked ok, I didn't look at the release bearing, but I am changing all of the clutch release mechanism in there anyway.
Now I just have to wait for the flywheel to arrive, so I won't get the car back until mid-late next week.
As I have it all out we are going to change the rear main at the same time, even though it isn't leaking. While we are there it would be silly not too, just in case.
Well after a disaster of a week on more car fronts than one, I picked up the car tonight. Basically it has cost me over double what it should so far. The dealer agreed once everything was out to wait 5 days for me to get a genuine flywheel from overseas as it was about 1/2 the price they quoted me. I paid extra to get an emergency order done and had it shipped to me in the agreed 5 days. The flywheel turns up I immediately take it to the dealer and they fit it, torque up the new bolts and then find that the pressure plate won't sit flush. Upon closer inspection at some point the flywheel has been dropped on its end and has a flat spot in it, it is stuffed. Had it fitted it would have been even more of a disaster as it would have been wildly out of balance and I would have had to have paid the labour cost to pull it all back out.
I then couldn't wait another 5 days and the dealer and I agree that I now need to pay hoist time as they can't get it off the hoist, so I had no alternative to buy one locally plus another set of bolts at considerable cost and overnight it in. I will send my damaged one back, and hope to at least get some of my money back, we'll see.
In any case, the result. I got in the car and put my foot on the pedal as I normally do and nearly punched it through floor, it is about 1/3 of the weight it was previously. I can't believe how light it is, it is amazing. All the shudder it had it reverse and the minute bit it had in the forward gears is totally gone.
The bite point is in about the same point in the pedal travel, but what I do notice is that the actual clutch bite is much more sharp in the take up.
I will wash up my old parts and take one last lot of photos to post on here in a few weeks time. Glad to have it back, but the bank account has taken an absolute savaging.
I then couldn't wait another 5 days and the dealer and I agree that I now need to pay hoist time as they can't get it off the hoist, so I had no alternative to buy one locally plus another set of bolts at considerable cost and overnight it in. I will send my damaged one back, and hope to at least get some of my money back, we'll see.
In any case, the result. I got in the car and put my foot on the pedal as I normally do and nearly punched it through floor, it is about 1/3 of the weight it was previously. I can't believe how light it is, it is amazing. All the shudder it had it reverse and the minute bit it had in the forward gears is totally gone.
The bite point is in about the same point in the pedal travel, but what I do notice is that the actual clutch bite is much more sharp in the take up.
I will wash up my old parts and take one last lot of photos to post on here in a few weeks time. Glad to have it back, but the bank account has taken an absolute savaging.
They do feel light when brand new, but it will stiffen a little over the next few weeks as the springs temper with use apparently, and will then stay the same for hopefully a few years and lots of miles.
I hope you'll forgive me for pointing this out but I think your experience is a good demonstration of why it's risky to source your own parts for someone else to fit, particularly on a labour intensive vehicle-disabling job. I realize it's done now but if there are any future issues with any of the parts you'll have to meet the labour cost to investigate - if the garage had sourced the parts it's all down to them. They will usually buy them much more keenly than you can too, so even with them adding a margin on should still be able to match what you'd pay elsewhere, in a like for like part & service basis.
Glad it's all done though and you can enjoy your car again.
I hope you'll forgive me for pointing this out but I think your experience is a good demonstration of why it's risky to source your own parts for someone else to fit, particularly on a labour intensive vehicle-disabling job. I realize it's done now but if there are any future issues with any of the parts you'll have to meet the labour cost to investigate - if the garage had sourced the parts it's all down to them. They will usually buy them much more keenly than you can too, so even with them adding a margin on should still be able to match what you'd pay elsewhere, in a like for like part & service basis.
Glad it's all done though and you can enjoy your car again.
thegoose said:
They do feel light when brand new, but it will stiffen a little over the next few weeks as the springs temper with use apparently, and will then stay the same for hopefully a few years and lots of miles.
I hope you'll forgive me for pointing this out but I think your experience is a good demonstration of why it's risky to source your own parts for someone else to fit, particularly on a labour intensive vehicle-disabling job. I realize it's done now but if there are any future issues with any of the parts you'll have to meet the labour cost to investigate - if the garage had sourced the parts it's all down to them. They will usually buy them much more keenly than you can too, so even with them adding a margin on should still be able to match what you'd pay elsewhere, in a like for like part & service basis.
Glad it's all done though and you can enjoy your car again.
Thanks for the info. Here in Australia you can import genuine parts for 50% of the cost of the local dealers normally. But yes, I took the risk and got badly burnt this time. However I have come out streaks in front in the past so I guess it catches up with you.I hope you'll forgive me for pointing this out but I think your experience is a good demonstration of why it's risky to source your own parts for someone else to fit, particularly on a labour intensive vehicle-disabling job. I realize it's done now but if there are any future issues with any of the parts you'll have to meet the labour cost to investigate - if the garage had sourced the parts it's all down to them. They will usually buy them much more keenly than you can too, so even with them adding a margin on should still be able to match what you'd pay elsewhere, in a like for like part & service basis.
Glad it's all done though and you can enjoy your car again.
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