L98 pressure plate? - ZR-1 Net Registry Forums

sdycke · 02-07-2015

hi ho. while replacing a spun pilot bearing (with a roller type bearing), I decided to go with a new clutch as well. However, the pressure plate in the LUC 04-113 kit (which was supposed to fit the ZR-1) is noticeably thinner and 3 lbs lighter than the stock Valeo unit. I read somewhere in SOLUTIONS this might be for the L98 cars. Just great. My question is: will this LUC pressure plate work in our ZR-1 cars? The release bearing measures the same. I don't drive aggressively or race... but once in a blue moon....you know. Anyway, the disc seems dimentionaly correct and does slide on the input shaft splines. The old PP wasn't bad at all, just that that while i'm in there....So should I go with the LUC PP and disc or just use the new disc and old PP? Kind of a BS question I know but I really need this thing wrapped up by Monday. Thanks for listening.

Dynomite · 02-07-2015

I had the same question I posed to Marc regarding a New In The Box L98 Pressure Plate I had on the shelf as part of a ZR-1 deal .....

A guy gave me one of those L98 Valeo Pressure Plates including the throw out bearing and clutch disk (tossed it on the deal for a ZR1 last year).
The Valeo L98 Pressure Plate is a bit thinner and was wondering if that will work on an LT5 (is it the same clamping pressure for example). All other dimensions are identical to the stock pressure plate except the thickness of the bolt connections for the flywheel bolts which are 1-3/16 inch thick rather than 1-5/16 inch thick for stock Valeo that was on the LT5.

Marc Haibeck replied that is an L98 pressure plate. The L98 Pressure Plate clamping force is about the same as an LT5 unit (maybe a bit less). The L98 Pressure Plate has less mass and tends to warp when drag race starts are made with a ZR-1. If not drag raced it probably will work for street use. You need to use L98 bolts. The LT5 bolts usually bottom out before the L98 pressure plate is clamped to the flywheel.

Don't use a Chinese disk. They work okay on an L98 but can explode at 7000 rpm.
Jerry also confirmed essentially the same information.

I set the L98 pressure plate aside as I also have a couple L98s.

I went with a Mcleod Pressure Plate and Stock Dual Mass Flywheel on that LT5 engine.

LT5 Pressure Plate TOP......L98 Pressure Plate BOTTOM

Differences in Pressure Plate Bolt Connection ........,,....Mcleoud Pressure Plate for LT5
Thickness between LT5 and L98 Pressure Plates

A26B · 02-07-2015

The original pressure plate for the ZR-1/LT5 is 3,000 lbf and the L98 is 2,800 lbf.

As Dynomite stated, DO NOT use the ZR-1 LT5 pressure plate bolts with the L88 pressure plate, they are too long.

Get the correct bolts and it should be fine for your style of driving, Or, re-use your ZR-1/LT5 pressure plate with the new disc.

sdycke · 02-08-2015

Thank you very much! Feels really good getting such quick, expert advice. How to pass it on? Think I will pick up the bill when my son meets us for lunch today! Wait! I always pay! How about a big tip? Or how about I just catch up on my dues.

02-07-2015	#1
sdycke Join Date: Jul 2011 Location: grosse isle, manitoba, canada Posts: 52	L98 pressure plate? hi ho. while replacing a spun pilot bearing (with a roller type bearing), I decided to go with a new clutch as well. However, the pressure plate in the LUC 04-113 kit (which was supposed to fit the ZR-1) is noticeably thinner and 3 lbs lighter than the stock Valeo unit. I read somewhere in SOLUTIONS this might be for the L98 cars. Just great. My question is: will this LUC pressure plate work in our ZR-1 cars? The release bearing measures the same. I don't drive aggressively or race... but once in a blue moon....you know. Anyway, the disc seems dimentionaly correct and does slide on the input shaft splines. The old PP wasn't bad at all, just that that while i'm in there....So should I go with the LUC PP and disc or just use the new disc and old PP? Kind of a BS question I know but I really need this thing wrapped up by Monday. Thanks for listening.

02-07-2015	#2
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,826	Re: L98 pressure plate? I had the same question I posed to Marc regarding a New In The Box L98 Pressure Plate I had on the shelf as part of a ZR-1 deal ..... A guy gave me one of those L98 Valeo Pressure Plates including the throw out bearing and clutch disk (tossed it on the deal for a ZR1 last year). The Valeo L98 Pressure Plate is a bit thinner and was wondering if that will work on an LT5 (is it the same clamping pressure for example). All other dimensions are identical to the stock pressure plate except the thickness of the bolt connections for the flywheel bolts which are 1-3/16 inch thick rather than 1-5/16 inch thick for stock Valeo that was on the LT5. Marc Haibeck replied that is an L98 pressure plate. The L98 Pressure Plate clamping force is about the same as an LT5 unit (maybe a bit less). The L98 Pressure Plate has less mass and tends to warp when drag race starts are made with a ZR-1. If not drag raced it probably will work for street use. You need to use L98 bolts. The LT5 bolts usually bottom out before the L98 pressure plate is clamped to the flywheel. Don't use a Chinese disk. They work okay on an L98 but can explode at 7000 rpm. Jerry also confirmed essentially the same information. I set the L98 pressure plate aside as I also have a couple L98s. I went with a Mcleod Pressure Plate and Stock Dual Mass Flywheel on that LT5 engine. LT5 Pressure Plate TOP......L98 Pressure Plate BOTTOM Differences in Pressure Plate Bolt Connection ........,,....Mcleoud Pressure Plate for LT5 Thickness between LT5 and L98 Pressure Plates __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 02-08-2015 at 12:59 PM.

02-07-2015	#3
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,396	Re: L98 pressure plate? The original pressure plate for the ZR-1/LT5 is 3,000 lbf and the L98 is 2,800 lbf. As Dynomite stated, DO NOT use the ZR-1 LT5 pressure plate bolts with the L88 pressure plate, they are too long. Get the correct bolts and it should be fine for your style of driving, Or, re-use your ZR-1/LT5 pressure plate with the new disc. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

02-08-2015	#4
sdycke Join Date: Jul 2011 Location: grosse isle, manitoba, canada Posts: 52	Re: L98 pressure plate? Thank you very much! Feels really good getting such quick, expert advice. How to pass it on? Think I will pick up the bill when my son meets us for lunch today! Wait! I always pay! How about a big tip? Or how about I just catch up on my dues.