Clutch issue with 01 996 Cup
10-17-2011, 01:36 PM
#1
Track Day
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Clutch issue with 01 996 Cup
Hi guys.
i got some problems with the clutch on my 2001 996 cup:
It works fine for the most of the time, but sometimes, it does not clear all the way, so i cant change gears.
it only happens on DOWNSHIFTS and especially after/while braking hard.
also, its only an issue, if the car has warmed up, so after a few fast laps around the track.
usually i downshift through every gear, plus releasing the clutch in every gear.
if the problem occures, i got a spongy pedal feeling, also the clutch does not return all the way up. i also tried "pumping" the pedal, like on brakefading.
then i tried to brake as hard as i could, and shift afterwards, but with the same problem.
it then takes 3 to 5 seconds to "recover" before i can change gear without a problem.
as i said, it NEVER happens on upshifts, only on downshifts.
i also have to press the clutch ALL the way to get into gear.
as soon as i start to release the clutch, the car starts to move.
you can barely feel the pedal moving.
theres also a lot of way infront of the point, where the pedal acutally starts to engage the clutch.
i hope this is a known problem, and some of you guys with your know-how can help me.
someone told me, that the early 996cups had clutchproblems.
i also have a small, other "Problem":
if the transmission is cold, so on the first half of a lap after the car has cooled down, the car starts so pull to the left, if i step on the gas.
if i step off the gas, the car pulls to the right.
its enough, to accelerate very slightly, just after the point of keeping your speed, as soon as i feel the car accelerating it starts to pull to the left.
if i hold my speed, and get off the gas, it starts to pull to the right.
i think this could be a LSD-problem, am i right?
NEVER had anything like that in any car... strange feeling.
however, after half a lap, its gone, and the car works good.
thank you guys!
Simon
i got some problems with the clutch on my 2001 996 cup:
It works fine for the most of the time, but sometimes, it does not clear all the way, so i cant change gears.
it only happens on DOWNSHIFTS and especially after/while braking hard.
also, its only an issue, if the car has warmed up, so after a few fast laps around the track.
usually i downshift through every gear, plus releasing the clutch in every gear.
if the problem occures, i got a spongy pedal feeling, also the clutch does not return all the way up. i also tried "pumping" the pedal, like on brakefading.
then i tried to brake as hard as i could, and shift afterwards, but with the same problem.
it then takes 3 to 5 seconds to "recover" before i can change gear without a problem.
as i said, it NEVER happens on upshifts, only on downshifts.
i also have to press the clutch ALL the way to get into gear.
as soon as i start to release the clutch, the car starts to move.
you can barely feel the pedal moving.
theres also a lot of way infront of the point, where the pedal acutally starts to engage the clutch.
i hope this is a known problem, and some of you guys with your know-how can help me.
someone told me, that the early 996cups had clutchproblems.
i also have a small, other "Problem":
if the transmission is cold, so on the first half of a lap after the car has cooled down, the car starts so pull to the left, if i step on the gas.
if i step off the gas, the car pulls to the right.
its enough, to accelerate very slightly, just after the point of keeping your speed, as soon as i feel the car accelerating it starts to pull to the left.
if i hold my speed, and get off the gas, it starts to pull to the right.
i think this could be a LSD-problem, am i right?
NEVER had anything like that in any car... strange feeling.
however, after half a lap, its gone, and the car works good.
thank you guys!
Simon
10-17-2011, 03:27 PM
#3
With problem 1. Bad slave cylinder or broken tab/tabs on pressure plate. If its a broken tab, driving it can be very bad for Mr Crankshaft as the rotating mass is out of balance and can hammer the crank bearings as result.
Problem 2. Tire pressure in rear tires is off/different or play in rear suspension parts bushings worn out in trailing arms etc.. or hub has wallowed out rear upright and bearing assembly is moving around. Or lastly shims are not tightened down or eccentric is moving allowing tow link to move around. Will not show itself when car is loaded/on the ground so must be up in the air and then yank the crap out of everything till You find play. If You dont find play then likely the wheel bearing hub wallowed out syndrome which will only present itself when warm/hot since once cooled it contracts and appears to be ok....
Problem 2. Tire pressure in rear tires is off/different or play in rear suspension parts bushings worn out in trailing arms etc.. or hub has wallowed out rear upright and bearing assembly is moving around. Or lastly shims are not tightened down or eccentric is moving allowing tow link to move around. Will not show itself when car is loaded/on the ground so must be up in the air and then yank the crap out of everything till You find play. If You dont find play then likely the wheel bearing hub wallowed out syndrome which will only present itself when warm/hot since once cooled it contracts and appears to be ok....
10-17-2011, 03:27 PM
#4
Track Day
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10-17-2011, 09:52 PM
#5
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I think you're going to have to validate that your clutch slave cylinder is acting as intended. Find out from Tilton what the spec is on the pressure plate, but it sounds like it's not releasing all the way. There is nothing that would only impact the downshift really... So it must just be that you are better at matching rev's there. If the slave cylinder is bad or the pressure plate is bent/broken it would release unevenly.
THe only other thing I can think of is that if your clutch plates were installed incorrectly... ...however this usually manifests itself as impossible shifting in every gear, every direction, after a very short period of time from install. (BTDT)
THe only other thing I can think of is that if your clutch plates were installed incorrectly... ...however this usually manifests itself as impossible shifting in every gear, every direction, after a very short period of time from install. (BTDT)
10-22-2011, 07:09 AM
#6
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hi guys.
Thank you guys very much for the help.
i tend to do all of the work on the car by my own, or with the help of my good friends, but since i really dont have any expirience with the newer models, the car is going to a raceshop to be fixed.
our/my guess is, as mentioned in this thread, a broken pressure plate...
Also there is a "clicking" noise out of the clutch while pressing/releasing the clutch.
ill let you guys know what the problem was, if someone cares
Thank you guys very much for the help.
i tend to do all of the work on the car by my own, or with the help of my good friends, but since i really dont have any expirience with the newer models, the car is going to a raceshop to be fixed.
our/my guess is, as mentioned in this thread, a broken pressure plate...
Also there is a "clicking" noise out of the clutch while pressing/releasing the clutch.
ill let you guys know what the problem was, if someone cares
10-22-2011, 09:26 AM
#7
Nordschleife Master
Agree with Glen. Most likely one of the pins is broken on the pressure plate. Pedal has to travel a lot further to disengage. Very common. Seen it many times. Would also account for noise when pressing clutch.
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10-22-2011, 10:10 AM
#8
Three Wheelin'
You did not mention if the clutch is a stock Cup clutch or a Tilton.
As far as the second problem goes, Glen is on target. You most likely have something that causes a change in toe settings, under throttle or braking, could be front or rear. I know a driver who's car had a similar problem. One of the bolts that holds the camber shims was broken (but not missing) causing the control arm to flex significantly. You need to look over all of the suspension bolts/joints before you drive the car again.
As far as the second problem goes, Glen is on target. You most likely have something that causes a change in toe settings, under throttle or braking, could be front or rear. I know a driver who's car had a similar problem. One of the bolts that holds the camber shims was broken (but not missing) causing the control arm to flex significantly. You need to look over all of the suspension bolts/joints before you drive the car again.
