Alright guys, I'm lost right now and really need some clutch help.

I just installed a brand new stock flywheel and a brand new Spec stage2 clutch to replace my worn out Spec stage1 clutch and stock flywheel (which had probably been resurfaced many times over the years).

I did everything by the books, including torqueing everything exactly as the Haynes manual said to. The installation went very well, didnt run into any stupid problems. I made sure the clutch fork was fully engaged on the throwout bearing, too. I finally got it all together last night and went to start the car and instantly heard this loud squealing noise. Once I let off the clutch the squealing went away. I tried one more time to push the clutch in-- it doesnt start squealing till just before the pedal hits the floor, and for some reason the gears are harder than usual to get into.

I shut the car off right away and got under the car and took the slave cylinder and its little housing off to see whats going on inside. It looks like when I have the clutch pushed all the way in the end of the clutch fork thats closer to the slave cylinder is being pushed out till it rubs against the pressure plate. In fact, there were little blue paint chips laying in the slave cylinder housing when I pulled it off the bellhousing.

So today I unbolted the driveshaft, crossmember, and torquearm so I could pull the transmission back out a few inches while being supported on a jack. I didnt bother taking the shifter off so its only back a few inches to get a wrench up there. I took the clutch fork out to inspect it to see if maybe it was bent or something. The fork looks fine and straight, its got some wear and tear on surface of the tips that pull on the lip of the throwout bearing (I have no idea why) but it doesnt appear to be bent at all.

Even if the fork was bent I'm not sure if this is the cause of the problem but I just dont know where to go from here. Is it a problem with the hydraulic system thats causing the fork to get pushed so far out that it hits the pressure plate?

The slave cylinder was replaced last year, but the master cylinder is original. They both seemed to work fine before this, fluid is full, and there are no leaks whatsoever. The system was recently bled, too.

Any help asap would be awsome, 'cause I'm stuck and just wanna drive my car.

 

The fork wouldn't be hitting the pressure plate, it only pulls away from it. Are you 100% sure you had the fork hooked onto the throwout properly? It can be a little hard to tell if you actually have it on right if you haven't done it before. With that said there's really not much you can do except pull the trans out more and take a look at everything else.

 

+1 it took me several times to get the fork on properly... take the rod out of the slave and see if it bent yet. when it was on inproperly it was hard to get ingear and would start to roll when i was forcing in first because it wasnt disengauged

 

Yes, I am absolutely positively sure the clutch for was completely engaged on the throwout bearing, because I've made that mistake in the past and its not pretty.

And yes, the end of the fork closer to the slave cylinder is pushed TOWARDS the pressure plate. After the pivote point on the transmission, the fork its pulling the throwout bearing away from the pressure plate, that I understand. I'm taking about the end of the fork that the slave cylinder pushes on, its pushing into the ouside of the pressure plate to get the clutch fully disengaged which is too far.

No, my slave cylinder rod isn't bent, if it was it wouldn't be pushing enough on the fork so it would never reach the pressure plate. Thank you guys for your input though.

Anyone else?

 

We are working thru this same problem, only fix we have found online so far is to grind down the fork for clearance. To me it doesn't sound like the right thing to do but like I said, that is all we have found as far as a fix.

 

I may be mistaken but I think the clutch fork should hit the bellhousing before it hits the pressure plate, if it over extends. I just recently had to track down a broken throwout bearing and that's what happened to me - would try to get the fork on the TO and it would just push all the way back into the bellhousing.

I'd say if it really is on the throwout (and the throwout is still clipped to the pressure plate like it should), the only thing I can think of is that the new flywheel is too tall causing the clutch to be moved too far towards the back of the car and the fork does not have enough "leverage" to work.

In any case there is really nothing you can do besides pull it off again.

 

I had the same nasty grinding noise when i swapped out my mcleod twin disc setup with a stock clutch setup. I had to adjust the mcleod master cylinder, then problem was solved. So if you have an adjustable master then give it a try.

I believe I ended up backing the nut off about 4 full turns.

 

I would bet it is the clutch fork hitting the PP. It's been known to happen before...

https://ls1tech.com/forums/lt1-lt4-m...-disaster.html

 

What a pressure plate looks like when the fork grinds on it.


http://www.rivercityperformance.com/...9&d=1244408854

http://www.rivercityperformance.com/...0&d=1244408890

 

Alright guys, I really do appreciate all the help. I dont have an adjustable master cylinder, so I'll just have to keep the idea of "grinding down the fork" as backup solution.

Before I do that though, I'm gonna see if I can find a store/dealership with a new LT1 clutchfork in stock and compare the shape of it to mine. For some reason, the tips of the fork that pull the throwout bearing away from the clutch look worn down-- maybe from years of rubbing on the throwout bearing while pulling it?

The surface is shiny and flattened where it looks like it used to be round, and even if only an 1/8th" of metal has been ground off over the years, that's more than enough to give the other end of the fork play to make a nice scratch ring around the pressure plate.

If a new fork looks identical to mine than I guess I'm stumped and will have to grind it down. But for now I'm gonna search for a new fork and probably get a hold of Spec to get their opinion on the matter too.

Once again, thanks for all your help guys.

 

Replacing the fork I'm not sure I would want to gamble having to take the tranny off once again if your theory didn't pan out. Grinding the fork is simple since very little has to be ground down. It will not ruin the integrity of the fork as long as you don't grind it flat...

 

Ground the fork, blead the system, test drove and all is well.

 

SS_RRR- I don't really think I'd be gambling with anything if I were to buy a new clutch fork and put it in. I've analyzed the heck out of this problem over the past few days and there not too many variables here, the clutch fork basically has to be the problem. I'm not running an odd setup here or anyhting, just a Spec sport clutch with a stock flywheel, so there's no reason why that wouldn't be compatible with a stock clutchfork.

Anyways, I think today I'm gonna give grinding the fork down a shot because I'm just not patient enough to wait for a new one to come in from gmpartsdirect.com. However when it does come in I'm going to install it because I dont like to 'mickey mouse' things like this on my car, atleast not permanently.

It also doesnt take long to get the clutchfork out because you dont actually have to remove the tranny. I took out my center console, crossmember, torque arm, and unplugged the electronics on the sides of the tranny. Then I unbolted the driveshaft from the diff yoke but didnt pull it out of the tranny so no fluid leaks, the end is being held up on a jackstand. Then I replaced 4 of the 8 tranny-to-bellhousing bolts with 5" bolts from a hardware store and used them to slide the tranny back a few inches while supporting the tailshaft on a rolling floorjack. The threads for the the tranny-to-bellhousing bolts was M10x1.50. I can slide the tranny back far enough to get my hand in there without hitting the shifter on the floorboard. It not very time consuming since I didnt have to actually unbolt and remove the shifter or remove the tranny completely.

 

What I meant is that you would be on the safer side to just grind the new one down.