It is unusual for a throwout bearing to break like this? (updated pics with new TOB!)
09-10-2012, 04:37 PM
#1
It is unusual for a throwout bearing to break like this? (updated pics with new TOB!) So it was the bearing that broke from what we can tell so far. The slave will have to be replaced as well and the fork was rubbing up against the pressure plate after it broke. Ever see a bearing break off like this? Pulling the rest out now.
Old busted TO bearing:
New HD TO bearing with Spec stage 2:
Old busted TO bearing:
New HD TO bearing with Spec stage 2:
Last edited by Rob94hawk; 09-21-2012 at 05:24 PM.
09-10-2012, 06:11 PM
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Spec pressure plates are notorious for being too thick and not clearing the fork. If you did not clearance the fork it may have put extra pressure on the TO bearing causing it to fail. Here's mine after being clearanced:
09-10-2012, 06:31 PM
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09-10-2012, 07:28 PM
#9
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Few thoughts:
1) Yes, I've seen the Spec TOBs fail in a similar manner -- usually the outer flange either tears off, or apparently spins and saws through the TOB casing. To help prevent it from happening on my older Spec 4, I welded the outer flange to the center of the throwout bearing (at the recommendation of someone on the forums). Click for big:
2) In regard to the clutch fork hitting the pressure plate, I machined some material off of the fork's t-shaped spacer, which pushed the clutch fork closer to the transmission adapter plate and away from the pressure plate. Had to pull the transmission 3 times to get the clearances right, but it worked out -- no interference problems whatsoever. I was concerned that having the fork closer to the slave cylinder would cause engagement problems, and that I might need to make a spacer to push the slave back, but it ended up being okay without. Clutch disengages about 2" from the top of the pedal travel.
1) Yes, I've seen the Spec TOBs fail in a similar manner -- usually the outer flange either tears off, or apparently spins and saws through the TOB casing. To help prevent it from happening on my older Spec 4, I welded the outer flange to the center of the throwout bearing (at the recommendation of someone on the forums). Click for big:
2) In regard to the clutch fork hitting the pressure plate, I machined some material off of the fork's t-shaped spacer, which pushed the clutch fork closer to the transmission adapter plate and away from the pressure plate. Had to pull the transmission 3 times to get the clearances right, but it worked out -- no interference problems whatsoever. I was concerned that having the fork closer to the slave cylinder would cause engagement problems, and that I might need to make a spacer to push the slave back, but it ended up being okay without. Clutch disengages about 2" from the top of the pedal travel.
09-10-2012, 10:51 PM
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Same thing happened to me with the TO bearing Zoom gave me... Failed after only a couple thousand miles. I got the Zoom clutch kit through Napa and showed them how there was no abnormal wear or heat discoloration causing it to fail.. They pulled a bearing out of a napa clutch kit they had right there and swapped it for me.. The TO bearing Napa gave me has a thicker lip holding on the piece that broke off too.
09-11-2012, 09:55 AM
#12
Same thing happened to me with the TO bearing Zoom gave me... Failed after only a couple thousand miles. I got the Zoom clutch kit through Napa and showed them how there was no abnormal wear or heat discoloration causing it to fail.. They pulled a bearing out of a napa clutch kit they had right there and swapped it for me.. The TO bearing Napa gave me has a thicker lip holding on the piece that broke off too.
09-11-2012, 10:30 AM
#13
FWIW I compared the "round with lip" TO bearing to the "square" one. The square one is referred to as LT4 type as it used to come with that PP vs the LT1 PP back when valeo was the only source of clutches before the China clones. The square one has a slightly thicker top flange. It came with my SPEC 2+. That clutch did not last long but the TO bearing was fine and I used it instead of the "round with tip" one that came with my CC 2500 which was marked "made in China"
If someone has a "GM" one, post pics
If someone has a "GM" one, post pics
09-11-2012, 11:16 AM
#14
Same thing happened to me years ago:
Just spot weld the hot to the inner cylinder like already mentioned:
I even have tack welds under the hat but they cant be seen in the pic and IMO they provide the most strength. This mod has been going strong for me for quite some time.
All of the TOB's available today are cheap Chinese **** knock-offs likely including all of the ones being used in every clutch kit regardless of manufacturer, including Spec. This particular mechanical failure is either material failure or assembly failure, take your pick and its becoming more common. IMO, where the cylinder rolls over to crimp the hat on, that metal stretches and becomes too thin to perform the job and then eventually, boom. The weld relieves the stress being applied to the thin metal and makes the thing much more solid.
Sucks that Spec cant stand behind this specific well known failure better than 3 months and therfore I will withhold further comment casue im certain it would be blamed your installation or improper break-in anyway.
Just spot weld the hot to the inner cylinder like already mentioned:
I even have tack welds under the hat but they cant be seen in the pic and IMO they provide the most strength. This mod has been going strong for me for quite some time.
All of the TOB's available today are cheap Chinese **** knock-offs likely including all of the ones being used in every clutch kit regardless of manufacturer, including Spec. This particular mechanical failure is either material failure or assembly failure, take your pick and its becoming more common. IMO, where the cylinder rolls over to crimp the hat on, that metal stretches and becomes too thin to perform the job and then eventually, boom. The weld relieves the stress being applied to the thin metal and makes the thing much more solid.
Sucks that Spec cant stand behind this specific well known failure better than 3 months and therfore I will withhold further comment casue im certain it would be blamed your installation or improper break-in anyway.
Last edited by wrd1972; 09-11-2012 at 11:41 AM.
09-11-2012, 01:47 PM
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I'm pretty sure it was one of your older posts that gave me the idea to weld mine -- I should have looked it up and given you credit. Thanks for posting that idea. Everything's holding up on mine thus far.
09-11-2012, 08:00 PM
#20
FWIW I compared the "round with lip" TO bearing to the "square" one. The square one is referred to as LT4 type as it used to come with that PP vs the LT1 PP back when valeo was the only source of clutches before the China clones. The square one has a slightly thicker top flange. It came with my SPEC 2+. That clutch did not last long but the TO bearing was fine and I used it instead of the "round with tip" one that came with my CC 2500 which was marked "made in China"
If someone has a "GM" one, post pics
If someone has a "GM" one, post pics