Are new throwout bearings available? - ZR-1 Net Registry Forums

ram_g · 08-09-2020

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...sn=632&jsn=632

Any ideas?

Edit: my car is a 1991.

TIA.

secondchance · 08-09-2020

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 · 08-09-2020

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

jss06c6 · 08-09-2020

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

Ccmano · 08-09-2020

Quote:

Originally Posted by 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

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

ram_g · 08-09-2020

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 · 08-10-2020

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 · 08-10-2020

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 · 08-10-2020

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

viper107 · 08-10-2020

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

08-09-2020	#1
ram_g Join Date: Jun 2020 Location: Houston, TX Posts: 183	Are new throwout bearings available? 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...sn=632&jsn=632 Any ideas? Edit: my car is a 1991. TIA.

08-09-2020	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,707	Re: Are new throwout bearings available? 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.

08-09-2020	#3
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Are new throwout bearings available? This might help, was an article in the Registry publication "Heart of the Beast" back in 2019. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

08-09-2020	#4
jss06c6 Join Date: Aug 2015 Location: Magnolia, Texas Posts: 884	Re: Are new throwout bearings available? 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

08-09-2020	#6
ram_g Join Date: Jun 2020 Location: Houston, TX Posts: 183	Re: Are new throwout bearings available? 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.

08-10-2020	#7
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Are new throwout bearings available? 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! __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

08-10-2020	#8
We Gone Join Date: Apr 2004 Location: ATL. GA. Posts: 2,163	Re: Are new throwout bearings available? 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. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

08-10-2020	#9
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Are new throwout bearings available? My throwout bearing completely came apart at about 22000 miles ... so unlikely but possible the metal is junk __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-10-2020	#10
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 746	Re: Are new throwout bearings available? my 94 z with 4 k miles on it back in 1999 squeeled sometimes while releasing the clutch __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5