When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey, thanks for reading this. I replaced a stock 4 speed trans in my 72 with a 5 speed tremec. However, I believe i messed up and didn't have the flywheel fully seated on the crankshaft before torquing the bolts. So it would still drive, but would get some pretty bad chattering if I didn't let the clutch out just right. Due to this, I hardly ever drove the car in the past 5 years. Finally I'm getting back after it and have removed the trans, which required pulling the whole motor, big job, so I want to make sure I get it right this time. Upon inspection of the flywheel and pressure plate, I noticed lots of discolored "hot spots/streaks" in one side of the flywheel and pressure plate, and could still see the surfacing marks on the other side, which makes me think the clutch was not making even contact. I'm pretty sure this is the source of the flywheel
problem, but I'm not sure what caused it. I have done several clutches on Chevys and other makes, and never had a problem. I did have the flywheel surfaced, and cleaned everything really good with brake cleaner before reassembling. When I bought the transmission, the sales man threw in a free Kevlar clutch disk and told me they wanted to "get their disks out there". I should have been skeptical but used it anyways, so I've always suspected the problem may have had something to do with the free clutch I used. But, more likely it was probably not due to the disk and was something I did wrong. Now when I replace it, I will wire wheel and clean the mating surfaces of the flywheel/crankshaft real well and then use a block of wood and hammer to fully seat the flywheel. I was thinking to also use an impact wrench on the bolts just so the vibration will help to fully seat the flywheel onto the crankshaft, after that, I will loosen the bolts and then torque them to specs with a torque wrench. Any comments on the symptoms or advice would be greatly appreciated.
When you had that flywheel resurfaced, possibly they cut it on a slight angle? I would at least have it checked for true, if not just replace it cause it's to big a job to chance it.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Since both have been heated on one side the chance of warping it really high...I would replace both and then make sure you break the clutch in properly before lighting up the tires
You need a new pressure plate, new disk and you need to have the flywheel professionally resurfaced.
When you go to reassemble the clutch, use a socket wrench to gradually pull all the fasteners evenly. Use a pattern to get them down so you don't warp the new pressure plate cover. Do not just air gun them all down all the way one at a time.
I do not believe the initial problem had anything to do with the flywheel torqueing down. Something warped. Either the flywheel was not surfaced properly (setup error?), or the pressure plate was warped from day one, or the pressure plate got warped during installation bolt down, or it has an internal spring problem. I do not see how the disc could even do this at all. So, regardless, the pressure plate is now doorstop material and the flywheel must be resurfaced, it has high spots now. Wire-wheeling will not help the surface. Suggest checking your new flywheel & pressure plate with a machinists ruler and feeler gauges to confirm flatness. You could check those two, but you would not catch me putting them back on!
Do it right, you are so right, it is much too big of a job to dive in here again!
And did you check your bellhousing for offset with a dial indicator? I hear that causes a whole host of problems with a Tremec. I'll be doing that Monday.
Last edited by leigh1322; Jul 18, 2021 at 09:55 AM.
Bear with me - 4 decades ago I was having an issue with my clutch. Grinding into gear was bad and shifting was hard. Adjustment was dead on. The parts all looked fine on the counter but I could not get a clean clutch release. I removed and replaced that clutch 3 TIMES in one day before solving the issue.
Long day story short...The pressure plate was warped. The speed shop looked the parts over and said they all look serviceable but we decided to assemble the clutch in the store on the counter. Flywheel was laid down, disk was eyeball aligned, pressure plate was tightened down and VOILA! The problem was staring right at us. The diaphragm fingers were perfectly aligned before assembly but they were way out of shape once the clutch assembly was all torqued down. Diaphragm spring was bad warped but not visible unless it was installed. Replaced the disk and pressure plate with McLeod pieces and we were good to go.
Last edited by stingr69; Jul 18, 2021 at 10:13 AM.
get a harbor freight dial indicator and check the fkywheel as it is bolted to the engine for runout. 35 bucks and you will use it for many other things later. https://www.harborfreight.com/clampi...tor-63656.html you can also spin it with the starter and eyeball it, but a couple thousandths will be hard to spot.
Hey, thanks everyone for the great advice! I was certainly gonna have the flywheel resurfaced, but am now considering just getting a new one (as Rescue Rogers suggested). For 5 years I've been wondering what went wrong, is it something I did, the clutch the resurfacing of the flywheel??? On the rare occasion I did drive the car, I dreaded having to put the car in reverse because the problem was exasperated, felt like my windows were gonna start breaking out!
Some comments to your advice and suggestions;
-- I have planned to use the dial indicator to check for trueness but was wondering about the crank end play. Couldn't this affect the dial indicator measurement?
-- Great suggestion on using a machinist ruler and feeler gauges to check for flatness. I only wish I had one, its nice when the tools are on hand!
-- I am in the habit of torquing down bolts evenly while changing to bolts on the opposite side (as one would do on a tire)
-- I'm definitely changing out the disk and pressure plate, probably going with the McLeod (but thats a topic on a different thread)
-- Yup, no lighting up the tires until the clutch is broken in
-- Another great catch, yes I did check the bellhousing offset and it appeared good. Its kind of a tedious test, but I think my results were accurate and the bellhousing didn't need adjustment. I'm going to check it again to be sure!
--Gonna get the dial indicator for sure, I'll need the plunger type to check the bellhousing runout.
clutch problem
