Clutch won't disengage

Got the car off blocks today for it's maiden voyage down the driveway.. but it grinds when I try to put it in first. If I try to go into 3rd, I can hear the clutch disc brushing on the flywheel as I'm pushing the shifter forward. So it seems like the slave is at least doing something, just not fully disengaging. I have the willwood 13/16" MC, remote bleeder, and slave cylinder from TPC. The pushrod is adjusted out pretty far, I was afraid to go further and run out of threads. Any ideas?

just a thought; when i bled my clutch it took what seemed like hours (probably 20 minutes in actuality) to fully bleed it. Is it possible that you need to spend some serious time under there bleeding that clutch? Mine really did take forever. Now i'm not running the same setup as you are, so I could be entirely off base, but i just thought i'd ask!

Nice to hear it's moving. Are you just pressure bleeding? I've found that a new master cylinder really needs a buddy bleed the first time to get all of the air out.

Rich

Did you use a remote bleeder or pressure bleed? My remote bleeder would suck air in when the clutch pedal returned to the top if the tip was not immersed in brake fluid.
Was the master cylinder bled before the system was filled? The fitting can be loosened to allow fluid to leak as the pedal is pressed to bleed it if you haven't. The slave is a pain to get all the air out of, at least mine is.
Did you measure for a shim?
Is your firewall flexing when the pedal is pressed? IIRC, you welded your firewall, so that shouldn't be it.
Does your clutch pedal engage at the same spot each time? If it does not you may have some air hiding.
The trans fluid made a difference also. I used swepco and it ground like horribly. With Redline it shifted much better and eliminated the grinding.
Mine is not as smooth as I would like going into first from a stop and shifting into second, every time I bleed it there is some improvement. I just ordered a Motive power bleeder.

Thanks for the ideas.. I have the remote bleeder line submersed in fluid and I'm just pushing the pedal myself. I thought this thing came with a speed bleeder on the end but I'll have to double check. Don't have the right cap for my motive bleeder, but I may buy one and try that. I didn't bleed either of the cylinders beforehand, so it's possible they're holding some air - I noticed some air bubbles coming up into the reservoir while I was topping off the fluid. The pedal feels pretty firm.. also, I did not measure for a shim - I thought that was only needed with the spec clutch setups?

Apparently, it is more critical with the Spec clutches to measure for a shim. Just throwing out ideas.

Ok.. did some more bleeding, and took the BH plate off to inspect. It looks like the slave is extending about 1/2" - 5/8", and I have about 1/16" gap between the clutch disc and flywheel with the pedal pressed down. How much gap should I be looking for?

I would think that is enough space between the clutch and FW. Could the pilot bearing be touching the clutch hub?

I suppose it's possible, the clutch is staying flush against the pressure plate and the gap I'm seeing is between clutch disc and flywheel. Although I would have noticed it when installing the clutch right?

Probably, but I do remember seeing at least one on here that had the issue. There was a picture posted of the scored pilot bearing. He had to machine off a little of the PB adapter to set it deeper. Was it any better after bleeding?

I had this problem. I used the 15x35x14mm bearing initially, installed everything to find out that the clutch would not disengage. I had to take it all back apart to switch to the 15x35x11mm bearing.

I was/am using an LS7 FW/PP and a LuK disc. Once the engine was running, I could not, by any means, shift from neutral to any gear. It may not happen to others depending on the disc they use Im guessing.

Heres the picture of the 14mm bearing after I got it out. [You must be registered and logged in to see this image.]

Any other ideas? How far out does the clutch push rod need to be to preload the MC?

bellhousing and adapter out of alignment? Reach up in the transaxle and try and turn the torque tube shaft when the car is in neutral and the clutch pedal is depressed.

Thanks, I'll try that.

Arthropraxis wrote:Thanks, I'll try that.

ok.. kind of confused. Are you having the same problem?

I don't see how the pilot bearing could be an issue, I'm using the stock LS1 flywheel (GTO) with TPC pilot adapter, TPC clutch disc and centerforce pressure plate. As far as I know these parts were sold to work with this application.

supes6 wrote:

Arthropraxis wrote:Thanks, I'll try that.

ok.. kind of confused. Are you having the same problem?

I don't see how the pilot bearing could be an issue, I'm using the stock LS1 flywheel (GTO) with TPC pilot adapter, TPC clutch disc and centerforce pressure plate. As far as I know these parts were sold to work with this application.

Mine has some resistance shifting into first at a stop and into second when driving. It has improved but still isn't were I want it. There is no reason why the parts you have should not work together, basically it is the same as any other system. From everything I can find the GM hydraulics hide air in a lot of places and people have a hard time getting it out.

Still trying to fix this.. I tried turning the driveshaft through the hole in the TT bell housing w/ clutch pedal depressed - it will turn with a set of big pliers on the trans coupler but I could not turn it by hand. I still have a 1/16" gap which seems like it should be enough, but the clutch disc is pressed up against the pressure plate. I am pretty confident that the slave is not the problem at this point. Any other ideas before I tear this thing down?

Did you measure the protusion of the shaft out the front of the turque tube? Perhaps the disc is bottoming out on the splines and is pressed against the flywheel. You could try adjusting the shaft rearwards with the clamp deal at the transmission input shaft.

Wait, you said "pressed up against the pressure plate", is that true? Does the disc move rearwards with the pressure plate when the clutch pedal is depressed? Or does it stay put and is actually pressed against the flywheel?

Rich

When the slave is actuated, the clutch disc and pressure plate move to the rear, away from the flywheel. The clutch disc stays glued to the pressure plate, I'm not able to slide it towards the flywheel at all.

I did check the driveshaft for pilot depth insertion before installing the clutch, and notched the trans input shaft so I could adjust it forward. Today I tried moving the driveshaft backwards 1/8" in case it was too far into the pilot bearing but that didn't seem to make a difference. I also loosened the bolts on the adapter plate, fired the engine for a few seconds and then re-tightened. Maybe I should loosen the bell housing to block bolts as well?

If the driveshaft coupler is not perfectly aligned, would it cause binding at the pilot bearing? I had to use a screwdriver to lever it in position, so it wasn't sliding freely between the TT and transmission.

Here is what I have for clearance... I was able to spin the clutch disc around a few times with a screwdriver, but it still stays tensioned against the pressure plate.

[You must be registered and logged in to see this image.]

Hey bud, The gap between your flywheel and clutch disc is more than enough. You have a pilot bearing or input shaft issue . Is it possible your disc is inverted. Sorry the maiden voyage has been delayed. Let us know how it proceeds. good luck

Did the flywheel side of your clutch disc have the splined hub protruding on it? Mine from TPC did, and I had to grind down the hub flush with the rest of the main hub. A couple slipped through the cracks Eric said. It was hitting the pilot bearing.

[You must be registered and logged in to see this image.]

Ok, I spent the morning pulling the trans and clutch out... my problem is just like Porschedoc posted. Clutch flange is contacting the pilot bearing adapter. Pretty ticked off right now.. but at least it doesn't appear to have caused much damage - the pilot bearing looks ok.

[You must be registered and logged in to see this image.]

Scratch that.. the bearing feels pretty notchy, probably needs replaced. What's the best way to pull the bearing out with the bell housing attached?

Can you get a pilot bearing puller in there, or clamp an allen with a slide hammer, hook the allen head through on the backside of the pilot bearing (tool will be angled to hook the bearing, not sure if there is enough clearance with the bellhousing on though) and give it a couple pops and it should come out if you have clearance.