Mystery clutch noise
#1
Mystery clutch noise
Hi Guys,
I seem to have developed a strange clutch noise in the car. I don't think it is SC related.
Noise is a grinding type rubbing sound, present only when the clutch is engaged. With the clutch depressed, the noise goes away.
According to service records, clutch was replaced by PO less than a year ago, albeit at a Lambo dealership.
Clues?
I seem to have developed a strange clutch noise in the car. I don't think it is SC related.
Noise is a grinding type rubbing sound, present only when the clutch is engaged. With the clutch depressed, the noise goes away.
According to service records, clutch was replaced by PO less than a year ago, albeit at a Lambo dealership.
Clues?
#4
I'm with Dave, Release Bearing is probably the culprit. Any light squeeling noise with that?
I'd check the receipt from the Lambo place and see if the Release Bearing (AKA Throwout Bearing) was replaced or just a new clutch disc. If it was just the clutch disc, you'll want to put a new release bearing and pilot bearing in and maybe replace your rear main seal while the whole clutch is out. All of those bearings will go out over time so you might as well put new ones in each time the clutch is done.
I'd check the receipt from the Lambo place and see if the Release Bearing (AKA Throwout Bearing) was replaced or just a new clutch disc. If it was just the clutch disc, you'll want to put a new release bearing and pilot bearing in and maybe replace your rear main seal while the whole clutch is out. All of those bearings will go out over time so you might as well put new ones in each time the clutch is done.
#5
Be warned, if your clutch is original (just new friction disk) then the throwout/release bearing for that system is NLA. Nice ... with the newer bearing you need a new guide tube and release arm I think. Need to check with suppliers.
Chris
Chris
#6
The reason I asked about which SPECIFIC parts were replaced was that if the release/throwout bearing was replaced and the release arm lever and guide tube WAS NOT replaced then THAT IS the problem.
The only new t-o bearing available AFAIK is the GTS spec bearing. This has been the case for many years. The GTS spec bearing has a different inner diameter and a different mating surface for the release arm lever - and thus the requirement to change all three.
If a GTS t-o bearing is used in place of a pre-GTS bearing with the pre-GTS leaver and tube then the result will be horrible-sounding nasty noises.
The difference in ID is only 1mm - but that's enough.
The only new t-o bearing available AFAIK is the GTS spec bearing. This has been the case for many years. The GTS spec bearing has a different inner diameter and a different mating surface for the release arm lever - and thus the requirement to change all three.
If a GTS t-o bearing is used in place of a pre-GTS bearing with the pre-GTS leaver and tube then the result will be horrible-sounding nasty noises.
The difference in ID is only 1mm - but that's enough.
#7
Originally Posted by Sterling
The release bearing is only used during the clutch being engaged...
Trending Topics
#8
Originally Posted by worf928
The reason I asked about which SPECIFIC parts were replaced was that if the release/throwout bearing was replaced and the release arm lever and guide tube WAS NOT replaced then THAT IS the problem.
The only new t-o bearing available AFAIK is the GTS spec bearing. This has been the case for many years. The GTS spec bearing has a different inner diameter and a different mating surface for the release arm lever - and thus the requirement to change all three.
If a GTS t-o bearing is used in place of a pre-GTS bearing with the pre-GTS leaver and tube then the result will be horrible-sounding nasty noises.
The difference in ID is only 1mm - but that's enough.
The only new t-o bearing available AFAIK is the GTS spec bearing. This has been the case for many years. The GTS spec bearing has a different inner diameter and a different mating surface for the release arm lever - and thus the requirement to change all three.
If a GTS t-o bearing is used in place of a pre-GTS bearing with the pre-GTS leaver and tube then the result will be horrible-sounding nasty noises.
The difference in ID is only 1mm - but that's enough.
With my clutch, one of the PO's mechanics replaced the arm and stud, but had the old style release bearing and sleeve in it. Like Dave said, that 1mm makes a big difference and it wore my release bearing out.
#9
Originally Posted by Sterling
what is the correct list of part numbers to use on the early clutch disk set up?
Release Bearing: 928 116 085 08
Guide Tube: 928 116 087 16
Ball Cup Bushing: 928 116 145 03
Ball Pivot for Clutch Arm: 928 116 075 01
Release Arm: 928 116 832 09
#10
Wow - thanks guys. I will dig out the part numbers. I seem to recall a discrepancy way back in what was replaced but I will check.
Sterling - what does torque tube bearing failure manifest itself as?
Regards,
Adam
Sterling - what does torque tube bearing failure manifest itself as?
Regards,
Adam
#11
Originally Posted by Adam C
Wow - thanks guys. I will dig out the part numbers. I seem to recall a discrepancy way back in what was replaced but I will check.
Sterling - what does torque tube bearing failure manifest itself as?
Regards,
Adam
Sterling - what does torque tube bearing failure manifest itself as?
Regards,
Adam
#14
Originally Posted by deliriousga
...you also have to replace the ball stud that the clutch arm pivots on. The new ball has a 10mm stud which is much larger than the original...
Also, I upgraded my '89 GT to the new spec and had no issue with the size of the ball stud on the housing.
EDIT: Perhaps the stud-size difference is taken care of by the bushing...
I'll need to find the Porsche doc...
EDIT: '93 Service Information Technik book lists the release bearing and guide tube. No mention of the release arm or bushing. Still looking...
PET shows the bearing superseded with a new bearing and tube. The tube is superseded with a new tube and release arm. Bushing and ball stud look the same for all S4 years.
#15
Originally Posted by worf928
John, are you sure? I've not once run across a reported issue with the ball stud - on S4s. (Perhaps it's a problem with pre-S4s?) The release arm, bearing, guide tube requirement is in at least one Porsche doc.
I have the AllData DIY subscription and I just checked it. It has the same info you have, clutch arm, release bearing and guide tube, but doesn't say anything about the ball stud. The FSMs have the progression of the ball stud size change, but I don't have those here to look up what it said.
Sorry about the confusion.
With the bushing, it just needs to be replaced when the clutch is done. Mine was non-existent when I pulled the arm out. The ball had ground a pit in the arm so I had to replace it too.