Are new throwout bearings available?

[ram_g]

Looks like I have a very intermittent squeal from the pilot bearing. May wait till it gets a bit more repeatable / frequent but am reading up on parts alternatives and what R&R involves.

A common piece of advice is to replace the clutch, PP, and throwout/release bearing when everything is apart. With only 13K miles the clutch action feels fine and I am loathe to replace it unless it really looks bad upon removal. But the TOB may be a good idea.

Not sure where to find a new TOB though! Jerry does not carry it. Rockauto and O'Reilly both list the AC Delco 614018 which seems to have the correct inside dia for the black label ZFs but sure doesn't look like the ZR-1 TOBs that I have seen.
https://www.rockauto.com/en/moreinfo.php?pk=5268666&cc=1041297&jsn=632&jsn=632&jsn=632

Any ideas?

Edit: my car is a 1991.

TIA.

[secondchance]

Below link is the correct throw out bearing for 90 to 92 (?). However, I am not sure of country of manufacture. Chinese version has been known to fail after the install. OEM versions come up for sale between $200 to 250 occasionally.

[Ccmano]

This might help, was an article in the Registry publication "Heart of the Beast" back in 2019.
H
:cheers:

https://farm66.staticflickr.com/65535/50208571682_43ebf89152_c.jpg (https://flic.kr/p/2juL481)

https://farm66.staticflickr.com/65535/50208571667_b0c92c369e_c.jpg (https://flic.kr/p/2juL47K)

https://farm66.staticflickr.com/65535/50208571662_6890244a34_c.jpg (https://flic.kr/p/2juL47E)

[jss06c6]

I seriously doubt you have a worn out throw out bearing... I recommend you chat with Bill Boudreau at ZFDOC.. (ZR51 Performance). The TOB, assuming it's original, is a very durable piece. You can certainly blow through the clutch in 13,000 miles if not driven "well". TOB, would not be the weak link though.

Sent from my SM-G950U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Ccmano]

I seriously doubt you have a worn out throw out bearing... I recommend you chat with Bill Boudreau at ZFDOC.. (ZR51 Performance). The TOB, assuming it's original, is a very durable piece. You can certainly blow through the clutch in 13,000 miles if not driven "well". TOB, would not be the weak link though.

Sent from my SM-G950U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Agreed, if you read the article I posted above, Haibeck says he has never seen a worn out Throwout bearing. Save your money.
H
:cheers:

[ram_g]

Thanks a lot for the article. I do have access to the Registry publications but I haven't read many back issues. Need to fix that omission! Wish I had read this in fact before I replaced my clutch fluid a few days back - (a) I didn't know what to make of the rubber bladder inside so ended up spilling a bunch of brake fluid, and (b) I used DOT 3 brake fluid like the cap said to! Anyway looks like my clutch is working ok, so I'll leave it alone for now.

As for the squeal, it's disappointing that "up to 25%" of the ZR-1s experience the pilot bushing spinning in the pocket, which I'm pretty sure is what mine is doing. It only happens at first start and only for a couple of seconds. I find I can minimize it by starting the car in neutral. Weird.

[Paul Workman]

Couple pointers:


There are two types of pilot bearings; the roller bearing unit and the bronze saturated bearing. IIRC, Marc Haibeck recommends the bronze bearing over the roller bearing.

That said, my roller* type prolly has 20k miles on it. I'm (a little) paranoid about clutch bearing; no doubt from having changes so many in my lifetime (NOT ZR-1s, however!! But, a clutch is a clutch!) So! I never sit, for example, at a red light or whatever and hold the clutch pedal down while in gear. I just imagine that bearing getting hot while I'm pressing the clutch pedal and how much fun it would be to pull the tranny to change (either) of those bearings. So far in ~ 20k miles, so good!


NOTE: I took the opportunity to change the clutch bearings when I changed flywheels "while I was in there", NOT because either had failed. Just sayin!

[We Gone]

Marc, replaced my pilot bearing about 5 years a go when doing the HP upgrade he installed the roller type at that time (his recommendation), 15k miles later never had any issues with it.

[LGAFF]

My throwout bearing completely came apart at about 22000 miles ... so unlikely but possible the metal is junk

[viper107]

my 94 z with 4 k miles on it back in 1999 squeeled sometimes while releasing the clutch

[WARP TEN]

Couple pointers:


There are two types of pilot bearings; the roller bearing unit and the bronze saturated bearing. IIRC, Marc Haibeck recommends the bronze bearing over the roller bearing.

That said, my roller* type prolly has 20k miles on it. I'm (a little) paranoid about clutch bearing; no doubt from having changes so many in my lifetime (NOT ZR-1s, however!! But, a clutch is a clutch!) So! I never sit, for example, at a red light or whatever and hold the clutch pedal down while in gear. I just imagine that bearing getting hot while I'm pressing the clutch pedal and how much fun it would be to pull the tranny to change (either) of those bearings. So far in ~ 20k miles, so good!


NOTE: I took the opportunity to change the clutch bearings when I changed flywheels "while I was in there", NOT because either had failed. Just sayin!

Paul is right that it is good practice to pop the trans into neutral when coming to a stop, rather than hold the clutch pedal down. As a matter of habit I have always done that on stick shift cars pretty much all my life. I have never had a clutch problem (not counting a Saab 99 whose clutch fork broke in the middle of a downtown intersection). I even popped into neutral when driving in bumper to bumper traffic and had to stop. Really not a problem to do that and it will save your clutch and throwout bearing. --Bob

[Vetman]

Additionally, I have always, when slowing down to a light using rpm match, sliped it into neutral without using the clutch.

[ram_g]

For clarification - since this thread seems to be drifting from my original question - I've been driving sticks for ~40 years and never once have had to replace a clutch or any clutch components, so I'm pretty comfortable with my competence in this area. Since my ZR-1 is new to me though and is making some pretty obvious pilot bushing/bearing noises, I thought I'd ask about the TO bearing if I was going to be in there anyway. I think the question has been answered.

[ZWILD1]

I have a new GM part in the package. I think when I did the replacement tranny in my first 91 Z I used the one that came with the new clutch kit. The GM one is clearly marked made in China and I bought it back in 2005 or 06.