You CAN take off too much from the flywheel. Did you get the flywheel used? Do you know if it has been resurfaced before? I got one from a junkyard and had it resurfaced before I put it in my car.. no problems. Got a new clutch and resurfaced the flywheel due to some hot spots, now it wouldn't fully disengage. I fought that thing for a month, was about to order a new flywheel and my friend stopped by after going to the machine shop. He had a flywheel shim. I was like, "well son of a gun". Not a lick of info on this site about it. I posted multiple times and all I got was, "you shouldn't have a problem, I didn't" or "you can't resurface an LT1 flywheel at all". Even the factory service manual doesn't list a tolerance for the flywheel thickness.

 

Brain,

Ah.. like between the flywheel and the crankshaft hub. Now thats cool. But if you don't know what the tolerance is, or where/how to measure it, I suppose what you need to know is the minimum thickness of the flywheel. Like with rotors.

Wonder what that number is ? I just mic'd my 90k mile flywheel from the donor car, and at the bolt flange its 1.830 inches thick. Checking around the circumference of the edge at each flange its within .003 all around.

Wonder what a new one measures ? Wonder what yours measured when you needed the shims ?

Gerry-

 

I wish I could tell you for sure. I was too anxious to get the car running with it to see if it fixed the problem. I do know that it had been turned at least 30 thousandths, and might have been a total of 40 thousandths. I used a 45 thousandths shim and it is just a teeny tiny hair too much, as if I press the clutch in as far as it can possibly go, the throwout bearing makes noise. Most people wouldn't even have the pedal down that far and notice it, I'm just tall and big so I do every now and then. I'm sure you could have someone check the thickness of their new flywheel around here. Or, if the dealer has one instock, you could always measure it. Hope that helps!

 

I've never installed a clutch in a new car like this, (did lots of them in old Camaros and Vettes) and since I'm going to be doing it pretty soon with the t56 conversion, I'm intereseted in hearing everything that I can about the shims. I saw someting about shims in one write up I read here on the net, but didn't know what that was all about. So, if I understand correctly, the shims that come with clutch kits are to space the flywheel from the crank to make up for machining?

Do I need to put a shim in equivalent to whtever is taken off the flywheel?

Enlighten me please guys.

 

Janny,

I think ideally that in order to maintain the absolute correct clearance, and maintain the factory setup for the slave cylinder and clutch fork, putting shims in is probably a good idea. If you shave the face of the flywheel, you'd have to shim between it and the crank hub to push it back, fooling the bellhousing mounting hardware/slave alignment/fork position into thinking the face of the flywheel hadn't changed position.

Brain... thanks for this tidbit. Its a really good one.



Gerry-

 

That is indeed a VERY good one.

 

Gerry, I just remembered after seeing this shim discussion that mine was shimmed for the same amount taken off the flywheel (15 thousandths) Forgot to mention that little tidbit the first time And nice work on the conversion, looks good!

 

Greg,

The link to the picture is from a friend's Impala that was just completed. It does look factory doesn't it.

The shims. Yep, I'd put .015 back if thats what they took off. I just found a very reputable flywheel company in SC that does this for a business. AC/Delco recommended them, and sells their wheels. Basically, my old LT1 flywheel and $40 gets me one of theirs with is guaranteed for 1 year. GM isn't going to guarantee anything, so I'm going to try the 'rebuilt' wheel.

Lets see what the thickness of that one is, and if they send me any shims. And TCI, the tranny guys, sell the shims. And look at
THIS LINK for shims.

Gerry-

 

Any of you guys figure out the thickness of a new flywheel. My clutch isnt fully disengauging after install and i need to shim the flywheel.

 

I resurfaced mine @ 115,000 miles. No problems.

 

Mileage is irrelevant. Break-in, driving style, and how much heat the flywheel has been exposed to affect it more than mileage. I see post after post from people that say they had theirs resurfaced and didn't have a problem. Then I see a few people say they had theirs resurfaced twice with no problems. Does anyone understand that it may have to be cut more or less each time depending on how bad it is? It could be me, but when someone asks about a problem they had with their car, the last thing you want to hear about it how 10 other people did a similar thing with no problems. Its like bragging about how you didn't have a problem. Same thing happens with headers; someone asks a question about LT install cause they are having a problem, you see 10 replies about how theirs just popped right in. Great help there. Sorry for the rant...back to the topic...

Jchevy, I haven't gotten a new clutch yet, but when I do, I'm gonna get a new flywheel as well. I'll be sure to measure it and post it on here.

 

Get a new one don't take any chances. You don't want to be like me. I only had the flywheel resurfaced twice and they took too much off the second time. Now I have to pull the tranny.....again

 

Why buy a whole new flywheel when you can use a shim? Ok, so you have to essentially replace the flywheel to put it on, but thats just labor. 2 - 3 hours max, and you saved a good $250.

 

Looking at new one in the box. Its 1.828 at the PP bolt ears. $178.00 from Dal Slabaugh at VanDevere Olds. Shipping was about 15.00 if I remember right.

I just said the heck with it, and went with a new one. I can always have the old one resurfaced some other time. I don't want to do anything other than DRIVE this thing when its done!



Gerry-

 

Excellent..thank you very much.