I'm in the process of replacing my clutch behind a zz4. The clutch was a Centerforce dual friction. The clutch did not last long. About 3000 miles, no track time and about 10 burnouts.

The flywheel has six bolts and appear to have loctite on them. I don't have air tools, so I have been using a rachet. I have 4 out, but two are STUCK. I while trying to get them out, I fear I may have rounded them some.

Anyone have suggustions as to get these bolts out?

AAron,
Do you have a torch of any type ? Do you feel safe using it around the engine ? If so, a little heat will "release" the loctite if that is indeed what is holding it. A propane torch held right on the bolt head for ten seconds or so is all it should take. Depending on how bad you have boogered up the bolts, you might be able to find a metric socket that will fit a little better.

Bill

Thanks for your reply. I do not have a regular torch, but do have a propane torch. I don't think I have damged the head that bad, but I could be wrong. The bolt head is a 9/16. If I can get any leverage on the head, is there a another solution? I thought I read somewhere about a socket made for stripped bolts.

Aaron,
9/16 sounds awful small for a flywheel bolt ? Usually they have an 11/16" head on them. Are these the bolts that hold the flywheel to the crnakshaft, or the clutch to the flywheel ?? Either way, if they have loctite on them (not really needed) then heat should break it loose. I have heard about the special sockets you mention but I usually have some old metrics or cheap sockets laying around and just take the next smallest size and hammer it onto the head of the bolt. Low tech, but it works :)

These are the flywheel bolts to the crank. I thought the same thing. Must have something to do with the new GM crate motors. Not sure, but that is what is in there. The pressure plate bolts were a pain in the as$$$$$$$$$$$$$$ as well. I will be trying the heat in the morning.

Not sure on the Centerforce clutch, not to happy with the turnout of the first.

Thanks Bill.

To add to what Bill said make sure you use a 6 point socket as a 12 point will allow it to slip off the bolt head easier.Rather than buying a special socket take one of the bolts you already got off to sears or AZ and find a socket that fits tight,then have at it.Also if its locktite holding it on, plain old carb cleaner will help,just spray the bolt like you would with rust buster.Oh yeah, don't combine this with the propane torch method
:clonk:

Got some car cleaner also. I will try that first. The the heat, but not unitl the carb cleaner is good and cleaned up! Thaks

Aaron,

John beat me to the six point thing. I'm with Bill on the 9/16 sounding small but I'm not up on the newer motors. As far as your premature clutch failure, did you follow the break in procedure for CFDF to the letter? There's a reason for my asking.

Yes, I did. The only thing I can think of is during that break in period I have 235 60's on the rear and they were wore out. When you acclerated and easied into the throttle, sometimes the tires would break lose. I don't think this would of damaged the clutch, but things do happend.

Aaron,

The reason I asked is because my first CFDF wore extremely fast after a situation at the track where there was not enough water down in the box and the spotter pulled me too far through. Consequently the tires stuck and I couldn't tell until a friend saw it and stopped me. Smoked the clutch briefly and it went away QUICKLY. Sounds as if your situation is different than mine, thought I might be able to help. Good luck!

Well those 10 burnouts I have done were not at the track. Just on two lane blacktop, out in the woods of course. I use a line lock for it. Could of done something there. The clutch on inspecting it is just gone.

I had the motor installed by a friend with the tranny. So I was not aware of the 9/16 inch bolt heads from the get go. i will be inspecting this as well.

Very difficult to tell in the car if the tires are spinning. The excitement, the noise,............I now have my mirror adjusted down to make sure I see tire smoke SOON. Manual cars must shock the tire enough to break them loose upon clutch release. You can see where I was going with this.

True. Really surprised at how quick it went away. It was alot of fun.

Well start with a good quality (the right size socket) preferably a new snap-on socket and if heat is an option then use it. An old trick for fasteners that are losing there grip with a socket is to use some "valve grinding compound" on the inside of the socket it acts like a gripper and will help BIG TIME in gripping a slightly damaged fastener. Also a great aid for getting out rusted phillips head screws. Put a little on a screw driver or socket and let the magic begin. also some of those flywheel bolts have been 12 point from on the crate motors so check to make sure you are using the right size socket. Paul.

Bolt issue aside, about the clutch life.

The Ceneterforce dual friction uses a fairly good material, pretty close to what Chevrolet uses on later model Corvettes. In the past when drag racing stick cars I would get ~ 200 passes with 2,000 rpm clutch release launches, less than half that with 4,000 rpm clutch release launches. How high an rpm did you go before side stepping the clutch pedal? A well seated clutch will put up with a lot of abuse. By the way, if you are doing your launches by releasing the clutch easy (feathering) you will dramatically shorten clutch life. Clutches actually last longer with a quick and full release.

Thomas

Are we talking about f/w bolts OR p/p bolts??

9/16" should be p/p bolts and I figure Bill is right-on with the 11/16" f/w bolts is all....

And I figure no more than a stock Perfection/Zoom clutch set should do nicely.... Unless you are talking about a road rearend geared car... 3.07's and such gearing...

pdq67

Thomas, most of the clutch releases are around 2000 rpms. Some 3000. All release were quick, no slipping the clutch or riding the clutch. Still seems like the the clutch wore a little to quick.

pdq67, I checked the bolts again and both the pressure plate AND flywheel bolts are a 9/16 inch headed bolt. The flywheel bolts are fine threaded and somewhat beefier, but both are the same wrench/socket size. Must be the right size also, They screw in and out nicely.

Now just get the other two out!

Aaron if the bolts are damaged to the point that neither a 6 pt proper sae socket or a smaller 6 pt metric socket will get them out, take a ride to Sears and pick up a set of Craftsman bolt/nut extractors. They are like a socket with spiril teeth inside them, they really grab onto even a fully rounded bolt. They work very well but on my set I already had to replace some of the sockets because the teeth started to chip off.

Also in a case like this always use penetrating oil (if rusty) and a little bit of heat as mentioned, the heat will draw the oil in or in the case of loctite soften the bond. Also tapping the fastener with a hammer helps to loosen it up.

Anyways for under $50 depending on the size of the set you purchase you will have more "secret weapons" for your toolbox. The work on any size bolt, metric or sae, even badly damaged.

Aaron,
Now that I realize that its a ZZ engine, I am pretty sure that has a one pc rear main seal crank and they use metric bolts. I am pretty sure the bolt head is 14mm.

Bill, I was figured that as well. I wondering why the motor has both standard and metric bolts. Intake has standard bolts as well. The intake has never been off. Oil pan bolts are metric. I called GM performance parts about this and they gave me the run around.

I just read in a new mag. that if you take a 6-point socket and grind or lath-cut it off 100 percent "square" about .060" or so, that you do away with the "recess/round" between the hex-corners, so that the WHOLE socket can fit deeper onto the bolt-head AND get a lot better bite!

It also said to grind them off smooth b/c the sucker might be really sharp now AND may cut you??

I've always wondered why I liked the "feel" of some wrenches and sockets better than others AND this explains it really good to me!! After all these years...

pdq67