Clutch arm pivot plastic bushing replacement
10-16-2008, 11:08 AM
#1
Racer
Thread Starter
Clutch arm pivot plastic bushing replacement
I have a bit of a shudder when releasing the clutch in 1st or reverse. Based on previous experience I want to replace the clutch arm pivot plastic bushing as a first remedy.
I had a '90 GT and did replace the bushing by pulling the slave cylinder, removing the lower bell hosing, levering the clutch arm off the pivot ball, shifting the lever to the side and replacing the bushing from above. That car had only 50.000 miles on clock.
My current '89 GT has 90.000 miles on the clock, and when I try to repeat the succesful procedure I can not lever the arm off the pivot ball and thereby not shift it to the side either. The bushing is completely worn and not restricting the movement of the arm. The pivot ball is apparently a bolt with a ball head, screwed into the motor block. The pivot plastic bushing goes on top of the ball and then the arm is slid onto the bushing.
My first question is: Why am I not able to lever off the clutch arm from the ball on a car that should be more worn, when I have done that succesfully earlier ?
Next question(s): Can I unscrew the pivot ball bolt from the block, replace the bushing on the bolt and reinstall the bolt ? How long is the shank/threaded part of the bolt ? Will there be space enough to do this maneuver ? Will there be any other parts coming loose if I remove that bolt ? Any adjustments required after removing that bolt ?
Ragnar
I had a '90 GT and did replace the bushing by pulling the slave cylinder, removing the lower bell hosing, levering the clutch arm off the pivot ball, shifting the lever to the side and replacing the bushing from above. That car had only 50.000 miles on clock.
My current '89 GT has 90.000 miles on the clock, and when I try to repeat the succesful procedure I can not lever the arm off the pivot ball and thereby not shift it to the side either. The bushing is completely worn and not restricting the movement of the arm. The pivot ball is apparently a bolt with a ball head, screwed into the motor block. The pivot plastic bushing goes on top of the ball and then the arm is slid onto the bushing.
My first question is: Why am I not able to lever off the clutch arm from the ball on a car that should be more worn, when I have done that succesfully earlier ?
Next question(s): Can I unscrew the pivot ball bolt from the block, replace the bushing on the bolt and reinstall the bolt ? How long is the shank/threaded part of the bolt ? Will there be space enough to do this maneuver ? Will there be any other parts coming loose if I remove that bolt ? Any adjustments required after removing that bolt ?
Ragnar
10-16-2008, 12:02 PM
#2
Team Owner
you could add some thick wire spacers to the pressure plate alignment rods (there should be three of them that stick out the rear side of the PP ) then loosen the PP bolts this should back the PP off enough to give you the clearance to remove the upper pivot arm and bushing.
Bend the wire into a U shape and fit it under the heads of the rods this keeps the PP from pulling the fork too far forward
Bend the wire into a U shape and fit it under the heads of the rods this keeps the PP from pulling the fork too far forward
10-16-2008, 12:11 PM
#3
Rennlist Member
generally, a grabby clutch is not due to the pivot bushing. when i did the holbert motor exchange, the bushing was nothing more than a few pieces of thin plastic 
(it worked well). scots clutch is grabbing and shuttering, really bad. he has a new bushing. Its in the clutch discs and or flywheel surface. could be warped or the discs could have uneven wear.
when we were putting the clutch back in , we did a few mistakes, one of which was to not line up the clutch arm on the bushing. with a new bushing we fought with the arm for an hour and almost got it, but gave up (using some big levers, two guys, etc) No way it was going back on . so , we had to loosen all the clutch pack bolts. it was the only way. If you cant get the clutch arm off the bushing, be thankful. It is probalby just fine and you would never be able to get back on again. (without clutch work). I dont think you can remove the ball and bolt with the room in there.
forget about it and live with the shutter, until you have the time to replace the clutch pack, and possibly the intermediate plate or flywheel resurfaced. how is the car to get into gear? intermediate plate adjustment. (see 2 disc clutch intermediate plate adjustment thread for some late night reading)
mk
(it worked well). scots clutch is grabbing and shuttering, really bad. he has a new bushing. Its in the clutch discs and or flywheel surface. could be warped or the discs could have uneven wear.when we were putting the clutch back in , we did a few mistakes, one of which was to not line up the clutch arm on the bushing. with a new bushing we fought with the arm for an hour and almost got it, but gave up (using some big levers, two guys, etc) No way it was going back on . so , we had to loosen all the clutch pack bolts. it was the only way. If you cant get the clutch arm off the bushing, be thankful. It is probalby just fine and you would never be able to get back on again. (without clutch work). I dont think you can remove the ball and bolt with the room in there.
forget about it and live with the shutter, until you have the time to replace the clutch pack, and possibly the intermediate plate or flywheel resurfaced. how is the car to get into gear? intermediate plate adjustment. (see 2 disc clutch intermediate plate adjustment thread for some late night reading)
mk
10-16-2008, 02:56 PM
#4
Nordschleife Master
I just replaced this on an 84 euro S2,
I managed to pop it off the ball then put the replacement bushing ON the ball first, then it took a great deal of struggling but got the arm up onto the plastic bushing and then levered it onto the plastic bushing.
I managed to pop it off the ball then put the replacement bushing ON the ball first, then it took a great deal of struggling but got the arm up onto the plastic bushing and then levered it onto the plastic bushing.
10-16-2008, 03:42 PM
#5
A shudder when releasing the clutch can also be a symptom of oil on the disk due to a leaking main seal or a worn pilot bearing. My want to check them out WYAIT.
Dennis
Dennis
10-16-2008, 05:33 PM
#6
Shameful Thread Killer
Rennlist Member
Rennlist Member
I did this same job on my 90GT a while back. It ws a hassle. I seem to remember having to slide the lever left and right a bit from below. It takes two people I think. I used a pry bar on top and a helper on the bottom. Don't think an 89 is any different?
10-16-2008, 06:11 PM
#7
Racer
Thread Starter
Yeah, as I said earlier I did the same job exactly the same way on my previous '90 GT. There is no difference between the MY's in that respect.
The difference lies in the wear of the clutch arm, or the throw out bushing, or a combination of those two.
What puzzles me is that the '90 GT with 50.000 miles was more worn than the '89 GT with 90.000 miles, and what was possible on the '90 GT is not possible on the '89 GT. A few millimeters short.
I did get the bolt out, replaced the bushing and reinstalled the bushing with the bolt in the clutch arm. What remains is to get the bolt catching thread and screw it back in place. And I need to lever the upper end of the arm a few millimeters to get there.
Ragnar
The difference lies in the wear of the clutch arm, or the throw out bushing, or a combination of those two.
What puzzles me is that the '90 GT with 50.000 miles was more worn than the '89 GT with 90.000 miles, and what was possible on the '90 GT is not possible on the '89 GT. A few millimeters short.
I did get the bolt out, replaced the bushing and reinstalled the bushing with the bolt in the clutch arm. What remains is to get the bolt catching thread and screw it back in place. And I need to lever the upper end of the arm a few millimeters to get there.
Ragnar
Last edited by Ragnar Joensen; 10-18-2008 at 04:02 PM.
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10-16-2008, 08:24 PM
#8
Rennlist Member
If I understand correctly, you have threaded the ball stud out of the upper bell housing .... and pressed it into the clutch release arm along with a new plastic bushing ????
If that picture is correct, then you are having difficulty rethreading the ball stud - at which I am not surprised
I did an update to the more recent, stronger ball stud on my '80 some time ago - and as the stud had to be retapped to M10, I loosened the transmission mount bolts, pulled the 4 bolts on the torque tube from the upper bell housing, loosened the intermediate shaft coupler .... and with little effort, slid the transmission backwards ~40mm : for my project, I then removed the clutch and bellhousing .... but for you, that would create ample space to rethread the ball stud. Actually, just back out the torque tube bolts a few mm, plus the other 2 steps, and you will have the desired space.
An alternative is to pull the ball stud - and saw off a couple of threads: it is under compression load, so that should not be too serious a comprimise.
Hope I understood your dilema correctly
If that picture is correct, then you are having difficulty rethreading the ball stud - at which I am not surprised
I did an update to the more recent, stronger ball stud on my '80 some time ago - and as the stud had to be retapped to M10, I loosened the transmission mount bolts, pulled the 4 bolts on the torque tube from the upper bell housing, loosened the intermediate shaft coupler .... and with little effort, slid the transmission backwards ~40mm : for my project, I then removed the clutch and bellhousing .... but for you, that would create ample space to rethread the ball stud. Actually, just back out the torque tube bolts a few mm, plus the other 2 steps, and you will have the desired space.
An alternative is to pull the ball stud - and saw off a couple of threads: it is under compression load, so that should not be too serious a comprimise.
Hope I understood your dilema correctly
10-16-2008, 08:53 PM
#9
Shameful Thread Killer
Rennlist Member
Rennlist Member
his doesn't need to be rethreaded. Same ball stud going back in. The alignment can be helped from below. Take your time, it will go back in right. Hard to reach down in there though.
10-16-2008, 09:02 PM
#10
Rennlist Member
.... I gather that he does not have enough space to align the ball stud to allow the first thread to engage ... sic - to 'rethread'. - not to imply that the female threads need to be (re)tapped.
10-18-2008, 11:04 AM
#11
Racer
Thread Starter
OK, job done !
My 15 year old son helped me out from below aligning the clutch arm, I pried the clutch arm back allowing the bolt slide in to place, aligned the ball bolt to the hole, got it catching thread, and tightened it.
What a sweet victory (and a sore arm) !
When I told my son that some of the fellow Shark drivers in the USA doubted that I would ever get the bolt back in place without lowering the clutch, he smiled proudly and said: "Yeah, well we did it anyway".
The victory just got even sweeter !!!
Ragnar
My 15 year old son helped me out from below aligning the clutch arm, I pried the clutch arm back allowing the bolt slide in to place, aligned the ball bolt to the hole, got it catching thread, and tightened it.
What a sweet victory (and a sore arm) !
When I told my son that some of the fellow Shark drivers in the USA doubted that I would ever get the bolt back in place without lowering the clutch, he smiled proudly and said: "Yeah, well we did it anyway".
The victory just got even sweeter !!!
Ragnar
.
10-18-2008, 03:58 PM
#13
Racer
Thread Starter
Peter,
I was afraid that I wouldnt make it to the Shark GTG next weekend. Pulling the clutch is more timeconsuming and You may find som parts that need replacement, and with just a few days on Your hand, spare part delivery time may become a problem.
After fixing the clutch arm pivot bolt I have now completed the Motor Mount job with new bolts, nuts and bushings in every hole and I have just replaced all sparkplugs, sparkleads, and the oil filter. All set and ready for new fresh oil. Tomorrow morning.
I have ordered new bushings for the steering rack. They have been on backorder for 3 weeks now, and I will wait until Tuesday, then I just install the steering rack with the old bushings. I dont want to miss the Shark GTG.
Now I will ease out with the family and a glass of red wine.
Ragnar
I was afraid that I wouldnt make it to the Shark GTG next weekend. Pulling the clutch is more timeconsuming and You may find som parts that need replacement, and with just a few days on Your hand, spare part delivery time may become a problem.
After fixing the clutch arm pivot bolt I have now completed the Motor Mount job with new bolts, nuts and bushings in every hole and I have just replaced all sparkplugs, sparkleads, and the oil filter. All set and ready for new fresh oil. Tomorrow morning.
I have ordered new bushings for the steering rack. They have been on backorder for 3 weeks now, and I will wait until Tuesday, then I just install the steering rack with the old bushings. I dont want to miss the Shark GTG.
Now I will ease out with the family and a glass of red wine.
Ragnar
10-19-2008, 01:03 AM
#15
Racer
Thread Starter
On my previous GT it actually fixed the shuddering. And it was worse on that car. The shuddering varied and in some situations it felt as if the transaxle was bent and rotated in an excentric pattern, causing fairly heavy vibrations.
Furthermore the previous car had the most annoying squeaky sound when in neutral and the clutch pedal released. The sound disappeared when I rested my foot on the pedal, not pressing down the pedal, just resting the foot on the pedal. That sound also disappeared. The bushing on that car was completely gone. On the current car the inner part of the bushing is gone (see picture in previous post), allowing axial play. Generally speaking this car appears to be less worn.
As mentioned by other posters, the shuddering may very well be generated by either a warped disk, or grease / oil on the contact surface. Or even reasons for that matter. A worn bushing may also contribute to unwanted wear of the associated parts.
I go one step at the time (well, I have also replaced the Motor Mounts) and will report back.
Ragnar
Furthermore the previous car had the most annoying squeaky sound when in neutral and the clutch pedal released. The sound disappeared when I rested my foot on the pedal, not pressing down the pedal, just resting the foot on the pedal. That sound also disappeared. The bushing on that car was completely gone. On the current car the inner part of the bushing is gone (see picture in previous post), allowing axial play. Generally speaking this car appears to be less worn.
As mentioned by other posters, the shuddering may very well be generated by either a warped disk, or grease / oil on the contact surface. Or even reasons for that matter. A worn bushing may also contribute to unwanted wear of the associated parts.
I go one step at the time (well, I have also replaced the Motor Mounts) and will report back.
Ragnar