Stock GTO Clutch Upgrade

6532 Views 75 Replies 17 Participants Last post by PBMunicorn, 11 mo ago

thekidinbuff

Discussion Starter · 11 mo ago

My 06 Goat just barely has 38k miles on it. Driving it the other day I gradually realized that the clutch engagement zone was getting lower and lower.. Well long story short, I'm 90% sure my slave cylinder is bad. Car is undriveable at this point.
While in there, Im pretty sure I want to replace the clutch. But im having a terrible time deciding. I want a heavier feeling clutch
Ive looked at Monster clutches but honestly I think they may be a bit too pricey for a car thats basically bone stock. Ive read that I could put in an LS7 clutch (using my OG LS2 flywheel im assuming?) but I cant confirm if that would be an upgrade.

Please give me feedback. The car is stock, 400hp and dont plan on doing much yet.

Thanks!

21 - 40 of 76 Posts

-Op-

· #21 · 11 mo ago

Stock is always a good choice. I have a Monster in mine and quite like it though. It will certainly live up to abuse.

Reactions: 1

evsnova74

· #22 · 11 mo ago

Yes in fact I ordered one not knowing that and now have an extra. Also have fun getting the old one out. You'll need to get a slide hammer type blind hole bearing puller.

Oh and get the f body slave and swap the GTO specific fitting over. You just drive out a roll pin

lsig

· #23 · 11 mo ago

thekidinbuff said:
My 06 Goat just barely has 38k miles on it. Driving it the other day I gradually realized that the clutch engagement zone was getting lower and lower..

If the fluid is low in the slave, fill it and pump it, if you get normal clutch action it’s the slave. You may have to fill it several times. My slave needed replacement at about 95,000. Even though you have low mileage it’s probably an age issue more than mileage. The clutch, on the other hand, should be fine at your mileage unless really beaten. I’m at 100,000 now and probably have a new clutch in the near future.

PBMunicorn

· #24 · 11 mo ago

keitho64 said:
Before going too deep into it check the clutch fluid. My guess is it’s black and clumpy looking. I’d suggest using a small Turkey baster and suck as much fluid out of the revisor and possible. Don’t go below the hydraulic line. Fill, pump the pedal a ton; repeat this whole process two to three times or until fluid is clear again.

I did this on mine last fall and it is back to normal operation. I am at 56,000 miles on the stock clutch.

I had a lot of problems with my stock OE clutch/slave when I bought the car. For some reason the slave failed a few weeks after I bought it (7000 miles) then at like 10k failed again. Both times it was the slave like splurging fluid into the clutch itself somehow or wasn’t shimmed properly idk. Never done a clutch install myself so I had always let a shop do it.
Long story short had a reputable shop put in ANOTHER oe clutch and slave at 17k about 5+ years ago. It’s been reliable ever since (knock on wood) lol and currently @ like 70k miles.
Biggest thing man is like someone else mentioned above, is to do the turkey baster method. It has prolonged my clutch tenfold. Every week or so I open the clutch master reservoir and sure enough fluid is black as shit and will usually have murky gunk in it. Apparently that’s grease traveling through the lines from the TOB itself.

Just suck like 9/10ths of the fluid out, fill it up. Pump the clutch like 10 times. Go back, repeat… do this like a total of 3 times. Cap off the fluid (make sure to use high bp DOT4) and pump the clutch a final 10 times. I do this once every week or so, sometimes I’ll go a month or two. Just based on pedal feel and if I feel like it’s been a while. Typically no matter what your fluid will be dirty always … even when I had this last clutch put in, When I got it from the shop my fluid was already black 🤣prolly from the the final bleed.. but if you do this regularly at least once a month or bare minimum every oil change, you’ll be way better off and your clutch should last a long time given no crazy abuse

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thekidinbuff

Discussion Starter · #25 · 11 mo ago

PBMunicorn said:
I had a lot of problems with my stock OE clutch/slave when I bought the car. For some reason the slave failed a few weeks after I bought it (7000 miles) then at like 10k failed again. Both times it was the slave like splurging fluid into the clutch itself somehow or wasn’t shimmed properly idk. Never done a clutch install myself so I had always let a shop do it.
Long story short had a reputable shop put in ANOTHER oe clutch and slave at 17k about 5+ years ago. It’s been reliable ever since (knock on wood) lol and currently @ like 70k miles.
Biggest thing man is like someone else mentioned above, is to do the turkey baster method. It has prolonged my clutch tenfold. Every week or so I open the clutch master reservoir and sure enough fluid is black as shit and will usually have murky gunk in it. Apparently that’s grease traveling through the lines from the TOB itself.

Just suck like 9/10ths of the fluid out, fill it up. Pump the clutch like 10 times. Go back, repeat… do this like a total of 3 times. Cap off the fluid (make sure to use high bp DOT4) and pump the clutch a final 10 times. I do this once every week or so, sometimes I’ll go a month or two. Just based on pedal feel and if I feel like it’s been a while. Typically no matter what your fluid will be dirty always … even when I had this last clutch put in, When I got it from the shop my fluid was already black 🤣prolly from the the final bleed.. but if you do this regularly at least once a month or bare minimum every oil change, you’ll be way better off and your clutch should last a long time given no crazy abuse

About 3 years ago I used a syringe to suck out the black and put new fresh fluid in. And every so often after that when it was darker Id do it again. It doesn't get all of it though. Because when I unclipped my clutch line from the tranny, it was pretty black. Im going to try to flush that line out before I put the new slave in.
The clutch itself is fine. Plenty of meat. More than I thought it would have. But Im still going to upgrade it while its on my garage floor

Reactions: 1

evsnova74

· #26 · 11 mo ago

thekidinbuff said:
About 3 years ago I used a syringe to suck out the black and put new fresh fluid in. And every so often after that when it was darker Id do it again. It doesn't get all of it though. Because when I unclipped my clutch line from the tranny, it was pretty black. Im going to try to flush that line out before I put the new slave in.
The clutch itself is fine. Plenty of meat. More than I thought it would have. But Im still going to upgrade it while its on my garage floor

Get a remote bleeder then you can actually flush the line with fresh fluid every so often. Mine gets bled every 5k miles, it's black every time.

Reactions: 2

Nothubertjfarnsworth

· #27 · 11 mo ago

evsnova74 said:
Get a remote bleeder then you can actually flush the line with fresh fluid every so often. Mine gets bled every 5k miles, it's black every time.

this is the way.

Reactions: 2

PBMunicorn

· #28 · 11 mo ago

evsnova74 said:
Get a remote bleeder then you can actually flush the line with fresh fluid every so often. Mine gets bled every 5k miles, it's black every time.

Whenever I get a new clutch ima do this and prolly the rear main and that little oil barbell thing too all at once. Always wanted a remote bleeder as the baster method isn’t a true bleed but it is definitely 100 times better than nothing for sure. If I don’t change out my fluid by the time it degrades that much, my pedal feel will be so soft if I’m wearing the wrong shoes I can barely feel engagement. And it’s worse when it’s 100 degrees outside too. Been like this forever since I bought it but the fluid changes have def prolonged my clutch life I think

Reactions: 1

evsnova74

· #29 · 11 mo ago

I didn't do the barbell, wish I had but I only read about it after I was done

Reactions: 1

PBMunicorn

· #30 · 11 mo ago

evsnova74 said:
I didn't do the barbell, wish I had but I only read about it after I was done

Yea I learned about it I think from like an old hoonigan video or something haha. It was a video titled something like “5 things to make your LS engine indestructible” 🤣

thekidinbuff

Discussion Starter · #31 · 11 mo ago

Update:
Transmission and clutch are out. Slave is definitely bad. It was very greasy in the bell housing. My rear main seal is wet so I ordered the new and improved GM cover. It was $60, i cant complain. LS7 clutch kit came yesterday.
I finally found a slide hammer to loan at Autozone, after I tried the other puller and it didnt have the strength. Removed the pilot bearing (along with some skin removed from my hand when the slide hammer pinched it

).
But when I put the new pilot bearing from the LUK kit in the crank, it moves within the crank....... I thought I might've read about this happening before. Its just a hair too small. I had to hammer to get it in at first. But once in I can slide it back and forth. I know this isn't right. Is the Luk one defective or do I need a GM one?

Nothubertjfarnsworth

· #32 · 11 mo ago

slide back and forth as in, in and out?

and you should be installing it with a seal driver tool, fyi.

thekidinbuff

Discussion Starter · #33 · 11 mo ago

Nothubertjfarnsworth said:
slide back and forth as in, in and out?

and you should be installing it with a seal driver tool, fyi.

It moves back and forth within its hole and partially out of it but gets stuck if i try pulling it out with my fingers. Ill have to pop it out with the tool.

I can find a seal driver to use but i figured everyone just uses a socket and extension. Thats all ive ever seen anyone use lol

Nothubertjfarnsworth

· #34 · 11 mo ago

you can mess up the pilot bearing with a socket.

thekidinbuff

Discussion Starter · #35 · 11 mo ago

I can understand how because its so soft but it shouldnt change the fact that the OD is the same or smaller than the hole its suppose to go in

Nothubertjfarnsworth

· #36 · 11 mo ago

any way you can snap a pic?

i suppose its possible the tolerance on the provided bearing is crappy. it might be a good idea to go with the acdelco and see if it is better.

Nothubertjfarnsworth

· #37 · 11 mo ago

if you have the original engine, i doubt it's the crank that is out of spec somehow. perhaps possible with an aftermarket crankshaft...

thekidinbuff

Discussion Starter · #38 · 11 mo ago (Edited)

I can get a picture later! Im at work right now.

Im a little confused. I just want to clarify something.
So I did buy from RockAuto the Luk clutch kit 04-905.
This only ever comes up for a 2004 GTO. Which had the LS1 motor in it. I have an '06 which is an LS2.
Even on Luk's site, it only lists the 2004 GTO and very early 2000s Vettes

Here's the link: LuK 04-905 | Schaeffler Online Catalog

Now I believe the LS1 and LS2 Pilot Bearings are two different part numbers. Im looking into that now.....

UPDATE: They are all the same pilot bearing part number between an '04 & '06 GTO and 2000 Corvette. Source is ACDelco Parts Lookup

evsnova74

· #39 · 11 mo ago

I bought the 04905 kit but didn't know it came with a pilot bearing, I had already ordered the acdelco one. They looked the same but I didn't measure, I used the acdelco one anyway. 05 btw, since you're doing the fw that comes with the kit that's what makes it work with the ls2 pretty sure.

Reactions: 1

Nothubertjfarnsworth

· #40 · 11 mo ago (Edited)

thekidinbuff said:
I can get a picture later! Im at work right now.

Im a little confused. I just want to clarify something.
So I did buy from RockAuto the Luk clutch kit 04-905.
This only ever comes up for a 2004 GTO. Which had the LS1 motor in it. I have an '06 which is an LS2.
Even on Luk's site, it only lists the 2004 GTO and very early 2000s Vettes

Here's the link: LuK 04-905 | Schaeffler Online Catalog

Now I believe the LS1 and LS2 Pilot Bearings are two different part numbers. Im looking into that now.....

UPDATE: They are all the same pilot bearing part number between an '04 & '06 GTO and 2000 Corvette. Source is ACDelco Parts Lookup

yeah, there are 3 different pilot bearings that work with LS motors. GTO's use the smaller of the 3. there is no mistaking it for the other two, lol. the input shaft of the tremec T56 transmission in the GTO's is the same for all 3 years, and can only be used with that smaller bearing. It's too long to be used with the large bearings, which would rest in the larger recess on the end of the crank.

~~AFAIK the corvette actually uses one of the larger bearings. the input shaft is different.~~ oops

it's likely you are on the outer end of tolerance. pilot bearing was probably made in china. try a genuine acdelco and see what happens. if it doesn't fit, you may need to try to get a bronze bushing instead.

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