GTO Slave Cylinder Replacement

[AMCRambler]

While under the car the other day I notice some fluid seemed to be leaking out of the bottom of the transmission where the bell housing bolts to the engine. At first I thought it might be engine oil that had run back from the small leak in my oil pan gasket but realized it was too much fluid and felt too thin between my fingers.

Popped the lid off the clutch reservoir and yep, fluid was low. Below the min marking. Ugh.

So looks like I'll be dropping the tranny to put in a new slave cylinder. Car has 57,000 miles so while in there I'll do the clutch too. Got a Spec Stage 1 and a new fly wheel ordered.

Been reading up on doing it and while it looks like a lot of work, nothing super difficult or requiring any special tools I don't have or can't borrow. Gotta love the internet, full how-to guides with pictures at the click of a mouse. Don't even need the shop manual.

http://www.gmhightechperformance.co...08gmhtp_ls2_ram_powergrip_clutch_kit_install/

This is my first clutch job, so any suggestions/recommendations/pointers? Seems pretty straight forward. I don't have a transmission jack, is it worth picking one up?

 

[Jimzz]

If you have never changed the trans fluid I would drain it before you start. Not a lot of weight but every bit helps, and new trans fluid as well.


What I have done is have a creeper and when I yank the trans out someone pulls my feet so I and the trans slide right out from under the car.

 

[tweakmonkey]

You have to drop the transmission to replace the clutch slave?

 

[phucheneh]

You have to drop the transmission to replace the clutch slave?

It's made into the the throwout bearing. No external slave/fork setup.

 

[NutBucket]

Yuck. That stinks.

 

[AMCRambler]

Yeah, it does kinda suck. Sound like its worse on the fbody GM cars though. Less room, tighter clearances, etc.

The car still shifts ok but when the slave finally lets go I don't want to get stuck somewhere. Better to take care of it now. Gives me an excuse to upgrade the clutch too. Gotta pay to play right? Hehe.

 

[phucheneh]

Yeah, it does kinda suck. Sound like its worse on the fbody GM cars though. Less room, tighter clearances, etc.

The car still shifts ok but when the slave finally lets go I don't want to get stuck somewhere. Better to take care of it now. Gives me an excuse to upgrade the clutch too. Gotta pay to play right? Hehe.

If 'playing' is pulling your trans every 50k, I guess?:hmm:

Seem to be a LOT of complaints of very early throwout bearing failures on those cars. All the same as yours.

I'm thinking I would go ahead and not replace that with a factory part.

 

[Doppel]

It's made into the the throwout bearing. No external slave/fork setup.

Wow, that sucks.

 

[AMCRambler]

I think they had their reasons for building it that way. Maybe able to exert more force directly against the friction plate rather than through a fork?

 

[phucheneh]

I think they had their reasons for building it that way. Maybe able to exert more force directly against the friction plate rather than through a fork?

Possible, but I don't think that's why. Major reason being that IIRC all that really matters in a hydraulic system is the size of the driving piston versus the driven one.

But also, I don't know if anyone uses those one-piece units other than GM and Ford. All the Japanese cars I've worked on (including recent RWD's) still had external slaves. Which kinda makes me think...not to stereotype here, but...I think the external setup is still regarded as the most bulletproof. While the internal one is cheaper and/or less complex to produce and assemble.

Same reason cars have stuff like 'quick connect' fittings...not 'quick disconnect,' as they're commonly called (often more like 'deceptively simple but LOL you'll be fooling with this damn thing for an hour'...connect).

...it's not for you. It's for the factory, 'cause it's foolproof and speedy.

 

[AMCRambler]

Possible, but I don't think that's why. Major reason being that IIRC all that really matters in a hydraulic system is the size of the driving piston versus the driven one.

But also, I don't know if anyone uses those one-piece units other than GM and Ford. All the Japanese cars I've worked on (including recent RWD's) still had external slaves. Which kinda makes me think...not to stereotype here, but...I think the external setup is still regarded as the most bulletproof. While the internal one is cheaper and/or less complex to produce and assemble.

Same reason cars have stuff like 'quick connect' fittings...not 'quick disconnect,' as they're commonly called (often more like 'deceptively simple but LOL you'll be fooling with this damn thing for an hour'...connect).

...it's not for you. It's for the factory, 'cause it's foolproof and speedy.

You say 50-60k isn't a lot of miles but the car is also going on 9 years old. Majority of those miles were surface road driving not so much highway or long commute. I Don't flog the car had or anything but when I drive I do it to have fun so it does get some fast shifts, down shifts, quick operation. Add to that this slave has to operate a clutch with enough clamping force to hold 400hp at the crank. I don't think it's entirely unreasonable to expect these to fail faster on this car than a run of the mill family Honda with 4 cylinders and a lot less power.

Then again, against maybe it's just typical GM engineering. I'd like to think the Aussie' s did a good job putting it together though. I haven't been left stranded yet.

 

[Jimzz]

^

The clutch slave on the GTO is a old design. Just off the top of my head I know jeep and ford used the same design. So not really a GM issue just a it happens thing.

 

[AMCRambler]

Thanks for the input fellas. I'll be starting it today. Hopefully finish it up by tomorrow.

Got my father in law's motorcycle jack to support the trans. Should do the trick.

 

[NutBucket]

Nice move on the Motive power bleeder. Great tool to have.

 

[Ketchup]

I've only replaced one clutch, on a '98 Mustang. We just used a board on a jack to hold the transmission. Hope you have some help. Seems to go pretty well with 2 people, but it still took the better part of a day.

Gotta agree with you on the internet AMCRambler. My dad and I were able to replace the spark plugs on our Mazda 6 thanks to YouTube.

 

[AMCRambler]

Nice move on the Motive power bleeder. Great tool to have.

Thanks. Yeah everything I read sais its the shit. I've tried using vaccum pumps and they never seal well enough to pull the fluid through well. After I do the clutch, I've also got some braided brake lines I want to put on so I figure $80 for the bleeder would be well worth it.

 

[NutBucket]

I've had no trouble with the vacuum pump method...this is even easier though!

 

[olds]

I've done it twice by myself without a transmission jack. Ran rope under the tranny and through holes on the frame. I could raise and lower the tranny with the rope and by pushing up on the tranny. As I got older, I just rented a tranny jack.

 

[AMCRambler]

I've done it twice by myself without a transmission jack. Ran rope under the tranny and through holes on the frame. I could raise and lower the tranny with the rope and by pushing up on the tranny. As I got older, I just rented a tranny jack.

Heh, a frame. That was an old car.

 

[phucheneh]

Trans jack really doesn't do much for you on a manual (or panless autos) without an adapter to bolt the trans to. Soooo much easier when you have that factory specialty tool that locks the trans to the jack. Even better if the jack has tilt adjustment.

But otherwise, akwardly laying the oddly-shaped case across a trans jack isn't much different from use using a floor jack. You can whip up a quick jig out of 2x4's or something if the trans is particularly heavy/unwieldy.

I don't see why you'd need a power bleeder...I think most of the instances where people have issues bleeding a clutch are because they're expecting it to work like bleeding brakes. You really have to be a bit more methodical in your pumping, and remember that the clutch is generally always going to stick to the floor after you open the bleeder valve; the person on the pumping end won't gradually feel the pedal get better like you do with brakes. Feels like you're going back to baseline every time, which can lead people into a perpetual 'lather rinse repeat' loop...

 

[olds]

Heh, a frame. That was an old car.

Trucks

 

[p_monks33]

Pretty common to experience a bad slave cylinder, as long as you are in there it's good you are replacing the clutch and flywheel, the likelihood of a contaminated flywheel is there, and will degrade the clutch life greatly. I burned a clutch in an 04 Gto withing 4k miles unknowingly running it with a contaminated flywheel. I now have an 05 with a stage 3 monster clutch and a new flywheel, best clutch I have ever had, combo'd with a short throw shifter and a Lou's short stick.

 

[AMCRambler]

Got it all apart yesterday. Today I'll hopefully be finishing up an putting it back together.

 

[AMCRambler]

Was hoping to be done today but not quite yet. I did find out the source of the fluid coming out of the bell housing wasn't my slave cylinder as original suspected. Appears it was the rear crankshaft seal leaking oil into the bell housing. Apparently a common problem on the LS2. Doesn't explain why the fluid in the clutch reservoir was below the min level though unless it was clutch wear.

Fought with the bell housing and it finally came off. Hosed it down with de-greaser and cleaned it good as it was nasty.

Pressure plate and clutch out next. I'm no good at reading clutch discs but the flywheel seems to be showing a good amount of wear.

With that all out of the way I could see the leaking crank seal and ran to the autoparts store for a new one. Comes with a gasket for the seal retaining cover as well. Pulled that off, cleaned it up, pressed in the new seal, RTV'ed the new gasket and starting buttoning it back up.

Everything was going smooth but of course that's when I effed up. That retainer cover has two bolts that go through the bottom of the oil pan into it. Looked up the torque on the retainer cover bolts and it was 18 ft lbs. Thinking those bolts from the bottom of the pan into the retainer were included, I proceeded to tighten them to that. Snap goes the bolt. $#%&*#!!! They're supposed to be 9ft lbs I come to find out. Fortunately it broke off where I could still grab the piece and get it out. But now I'm waiting for new bolts to ship... sigh.

Looks like maybe next weekend I'll be done. Stay tuned.

 

[phucheneh]

Why are you torquing tiny bolts like that? I don't understand people's paranoia. All you're doing by pulling out the torque wrench is giving yourself more leverage to break stuff.

Also your flywheel looks pretty terrible. Those colored spots are typically harder than the metal around them and will cause vibration/chatter and such down the line, if they aren't already.