1984 NA 944 Clutch Pedal Vibration (New Clutch)
07-27-2016, 12:02 PM
#1
Racer
Thread Starter
1984 NA 944 Clutch Pedal Vibration (New Clutch)
Hi All,
Long time time rennlist reader, first time poster (I'm sure someone will be kind enough to let me know if this thread is in the wrong place). I've owned a NA 1984 944 for a little over a year now. Rubber centered clutch disk went recently so I took the plunge and did a Sachs clutch kit (new spring centered clutch, throwout bearing, pressure plate, pilot bearing, rear mainseal, guide tube, needle fork bearings, fork pin, pressure plate bolts). Out of all the jobs I've done on this car this one really made me question whether it was all worth it. Took me about a week working every night after work. Got the car back together and it wouldn't rev past 3000. Replaced the speed and reference sensors; good as new. New clutch felt amazing... for two days. Then I noticed the clutch pedal was sticking, hard to push in and didn't always want to come out. Then it got worse and I realized I could feel a thumping vibration in the pedal. It isn't sticky, but the vibration causes the pedal to depress and come up in jerky motions. I do some testing and find that, in neutral and in gear, the pedal vibrates significantly (enough to move my leg) but only when being depressed and released. If you press the pedal down slowly in neutral, you will feel the vibrations until you stop depressing it (anywhere in the range- it doesn't have to be depressed all the way to stop, as long as the pedal isn't moving, you stop feeling the vibrations). The vibrations are directly related in frequency to the engine rpm's. They seem to be significantly less noticable at higher (4000+) rpms, but definitly still there. The car is perfectly drivable and the new clutch grabs great, but I can feel the vibrations worsening by the day and soon I'm sure the pedal won't come back out. When I look into the inspection hole with the car running at idle the throwout bearing seems to be jumping all over the place, from the front to the rear.
I followed all written procedures for replacing the clutch to a T and took my time with everything. I installed the same amount of shims on the new throwout bearing as were on the last one and made sure the spring washer was facing the correct direction. My old fork had worn contact points but they all do and I've never heard of it causing problems. My slave cylinder is fine, no leaks, pedal is smooth with car off. I didn't have the flywheel machined but it was smooth as butter even with the broken rubber clutch. I replaced the guide tube and right now it's suspect number one. I remembered as I was writing this that the tube came with a sticker on the OD where the TB rides. I, being an idiot and not understanding how everything worked, removed the sticker with a razor blade and probably left big nicks on it. I also didn't grease it. I will be tearing this f* thing apart again tonight to try to see what's up. If anyone has had this problem or has an idea please weigh in. Thanks guys.
Long time time rennlist reader, first time poster (I'm sure someone will be kind enough to let me know if this thread is in the wrong place). I've owned a NA 1984 944 for a little over a year now. Rubber centered clutch disk went recently so I took the plunge and did a Sachs clutch kit (new spring centered clutch, throwout bearing, pressure plate, pilot bearing, rear mainseal, guide tube, needle fork bearings, fork pin, pressure plate bolts). Out of all the jobs I've done on this car this one really made me question whether it was all worth it. Took me about a week working every night after work. Got the car back together and it wouldn't rev past 3000. Replaced the speed and reference sensors; good as new. New clutch felt amazing... for two days. Then I noticed the clutch pedal was sticking, hard to push in and didn't always want to come out. Then it got worse and I realized I could feel a thumping vibration in the pedal. It isn't sticky, but the vibration causes the pedal to depress and come up in jerky motions. I do some testing and find that, in neutral and in gear, the pedal vibrates significantly (enough to move my leg) but only when being depressed and released. If you press the pedal down slowly in neutral, you will feel the vibrations until you stop depressing it (anywhere in the range- it doesn't have to be depressed all the way to stop, as long as the pedal isn't moving, you stop feeling the vibrations). The vibrations are directly related in frequency to the engine rpm's. They seem to be significantly less noticable at higher (4000+) rpms, but definitly still there. The car is perfectly drivable and the new clutch grabs great, but I can feel the vibrations worsening by the day and soon I'm sure the pedal won't come back out. When I look into the inspection hole with the car running at idle the throwout bearing seems to be jumping all over the place, from the front to the rear.
I followed all written procedures for replacing the clutch to a T and took my time with everything. I installed the same amount of shims on the new throwout bearing as were on the last one and made sure the spring washer was facing the correct direction. My old fork had worn contact points but they all do and I've never heard of it causing problems. My slave cylinder is fine, no leaks, pedal is smooth with car off. I didn't have the flywheel machined but it was smooth as butter even with the broken rubber clutch. I replaced the guide tube and right now it's suspect number one. I remembered as I was writing this that the tube came with a sticker on the OD where the TB rides. I, being an idiot and not understanding how everything worked, removed the sticker with a razor blade and probably left big nicks on it. I also didn't grease it. I will be tearing this f* thing apart again tonight to try to see what's up. If anyone has had this problem or has an idea please weigh in. Thanks guys.
07-28-2016, 10:40 AM
#2
Racer
Thread Starter
Chewed up throwout bearing
So I tore the car down last night to investigate this issue. When I rotated the wheels (with the whole drivetrain still in), I noticed a squeaking sound coming from the clutch housing. I also noticed my new-to-me transmission with supposedly 20k on it has excessive play : ( ... Anyway, when I took the starter off I found a washer I must have dropped in there during the job, and some metal shavings. At least it's not bits of clutch disk. pulled the bell housing off, boom there it is. my throwout bearing's ID is F* up in a major way. Definitely where the vibration was coming from. Pictures are attached. Clutch is fine, no other damage. It was midnight by the time I got it out so I couldn't do CSI: clutch edition, but I'm fairly certain the splines on the driveshaft somehow bit into the inside of the bearing. The only thing I can't understand is HOW??? The pilot bearing is fine, and I think it would have been very noticable if the clutch wasn't centered, but it grabbed and drove with no vibration unless the pedal was pushed. The other thing that scares me is that this didn't happen until a few days after the clutch job. So even when I fix this I have to hold my breath for a few days. Again, if anybody's seen this before, please weigh in. Otherwise I will order a new throwout bearing and guide tube and try this all again. Oh, another problem: my clutch bell housing will not come out over the still attached flywheel and pressure plate. The pressure plate bolts must be undone 1 by 1 through the starter hole and then the clutch and PP come down with the housing. Anybody ever experienced this?
07-29-2016, 10:49 AM
#3
Racer
Thread Starter
So I got under the car again yesterday and took a closer look at the pilot bearing/flywheel. The flywheel seems to have some dips in the surface. Clutch probably heat treated the surface but I'm going to go to a shop and see if they can fix it. Anybody selling a flywheel? lol. New pilot bearing, throwout bearing, and guide tube coming tomorrow.
08-03-2016, 11:07 AM
#4
Racer
Thread Starter
Got my flywheel back resurfaced today. Nice and shiny. Would anyone recommend getting a new clutch because it was used on the warped flywheel? I'm thinking since it was brand new and I only drove it for a few days I'm gonna throw it in there and hope for the best. If my throwout bearing gets here today I'll put everything back together.
08-03-2016, 08:51 PM
#5
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I wish I could help, but I haven't dug into my clutch yet. Good luck with the new parts it sounds like you found the problem but not what caused it. My 85 944 is bound to need a new clutch when it's rubber Center goes out so I'm subscribed to see how your repair turns out.
08-03-2016, 10:11 PM
#6
Racer
Thread Starter
I'll keep you in the loop. Just re installed the clutch. Being super **** about greasing everything and torquing everything perfectly in the right pattern. Should have the car back together tonight/tomorrow. Plan is to baby it for a few hundred miles to let the clutch mesh properly with the flywheel. Unfortunately I can't celebrate when it's all together because I have no idea when this problem could pop up again
08-05-2016, 10:44 AM
#7
Racer
Thread Starter
Well it drives. I feel a vibration in the pedal that behaves the same way as the old symptom but 100x less strong. I'm probably paranoid and will lose my s*** every time I feel or hear something clutch related. But then again the last one started soft and got worse so we'll see. I might just baby the car for the rest of its life haha.
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08-05-2016, 10:59 PM
#9
Racer
Thread Starter
For anyone who reads this afterwords looking for a fix/tips on the clutch job; here are the lessons I learned:
Resurface the flywheel. It might look fine. Do it anyway. The money you'll save by not doing it won't make up for having to do the whole clutch job again.
Grease everything that's supposed to be greased. Sounds obvious but don't skip on anything.
Clean all the mating surfaces thoroughly.
Torque everything in the correct pattern to the correct spec.
When you go to put the clutch housing back on, remove the alignment tool. You'll have to get the guide tube into the hole in the throwout bearing.
Do not "break in" the clutch for an hour and then drive hard. Give it at least a week. You'll thank yourself.
Understand the way all the parts work together as best you can. The more you understand the smoother things will go.
Resurface the flywheel. It might look fine. Do it anyway. The money you'll save by not doing it won't make up for having to do the whole clutch job again.
Grease everything that's supposed to be greased. Sounds obvious but don't skip on anything.
Clean all the mating surfaces thoroughly.
Torque everything in the correct pattern to the correct spec.
When you go to put the clutch housing back on, remove the alignment tool. You'll have to get the guide tube into the hole in the throwout bearing.
Do not "break in" the clutch for an hour and then drive hard. Give it at least a week. You'll thank yourself.
Understand the way all the parts work together as best you can. The more you understand the smoother things will go.
11-06-2016, 10:48 PM
#10
944 fork
I did a clutch job on my 944 but the throw out bearing is being pushed/pulled sidewaysish could iv installed the fork wrong or is it crooked? Or whats going on any help will be appreciated
11-07-2016, 12:11 AM
#11
Racer
Thread Starter
Miguel, did the shaft that the fork rotates about go into the bell housing easily or did you have to force it? Does the clutch pedal feel different now than it used to? If not, how did you notice the problem?
11-07-2016, 07:47 AM
#12
944 fork
its my first 944 never drove it... The trow out bearing was not installed properly, it fell when i removed theclutch housing... I tried to engage gears after installation of new clutch, pressure, slave, master, line, and resevuar... How i noticed i got under with a wire cam(drain cam) and got my girl friend to push the pedal for me... The pedal is soft but when engine running youll feel some shaking (halfway down the clutch pedal) then all the way down youll hear a shhh sound.
11-07-2016, 09:55 AM
#13
Racer
Thread Starter
I'm sorry, I don't immediately know what that might be. Some vibration in the pedal is normal if the clutch was replaced with an aftermarket, non-rubber center clutch. Did you grease the guide tube? I'm pretty certain that's where I went wrong. And when the pedal is all the way down, the throwout bearing should be riding up on the guide tube, which could be your shhh sound.
11-07-2016, 01:45 PM
#14
944 fork
will look into it soon or later bad weather.... Thank you for the insight
12-11-2016, 09:45 AM
#15
It was a bent fork
I'm sorry, I don't immediately know what that might be. Some vibration in the pedal is normal if the clutch was replaced with an aftermarket, non-rubber center clutch. Did you grease the guide tube? I'm pretty certain that's where I went wrong. And when the pedal is all the way down, the throwout bearing should be riding up on the guide tube, which could be your shhh sound.
