: 06 cts v ls7 clutch vibration



06vmike
07-20-13, 04:05 PM
i just got the LS7 clutch kit installed with the ls7 slave a few days ago and im getting some bad vibrations at 2.5k and up i have done some research on it and some people have said it was installed and great and some people have had probs with the vibration im just wondering if anyone out there can help me out and give me some ideas as what i should do to fix this sucks to have spent over 1k and have it feel worse than it did.... any help would be great

HAMSTAR
07-20-13, 08:51 PM
What are your other mods? The DM flywheel can mask vibrations-- actually it is designed to do so. If you are still on the stock crank pulley, take a look at it to see if the rubber is squeezing out and/or if it's wobbling or not. That is assuming there were no problems with the clutch install or new flywheel.

Naf
07-21-13, 04:24 AM
YOu have to just drive the clutch. the vibration will work its self out...

It happened to me when i first installed then after about 100mi it went away

06vmike
07-21-13, 07:14 AM
ya i have put about 60-70 miles on so far and it just does not feel good.. does not feel like its putting all the power down not sure if it will feel stronger in time or whats going on

Naf
07-21-13, 01:32 PM
It only vibrates at a certain rpm, nuttin before, and you are too scared to try after?

Just drive normally and let it find its happy place...You will be pushing it hard and punishing it soon

FuzzyLogic
07-21-13, 01:48 PM
YOu have to just drive the clutch. the vibration will work its self out...

Recipe for disaster. You got lucky. If that vibration is being caused by improperly torqued bolts on the flywheel, pressure plate, or driveshaft coupler, that vibration is the only warning he'll get before sudden driveline destruction.

06vmike
07-21-13, 03:46 PM
hey fuzzy any chance you know what the Tq specs are on the flywheel, pressure plate, and driveshaft coupler, or the easiest place to find that info so i can call my transmission shop and ask him what he torqued um too

this is what i found on ls1tech on someone write up any one confirm this

install new flywheel: Torque in a star pattern (like a wheel) and do this in 3 increments: 15lb-ft, 37lb-ft, 74lb-ft.

install the clutch: Torque in a star pattern (like a wheel) and do this in increments. the dealer did not specify, but the final torque is 52lb-ft.

FuzzyLogic
07-21-13, 03:58 PM
hey fuzzy any chance you know what the Tq specs are on the flywheel, pressure plate, and driveshaft coupler, or the easiest place to find that info so i can call my transmission shop and ask him what he torqued um too

He probably doesn't remember. If you're going to ask him, don't give him a hint about the right numbers. Just ask him what he did.

Per spec, the pressure plate should be torqued to 52 ft-lbs during the third and final stage of the star pattern sequence, but I recommend 48 ft-lbs and blue Loctite. Once you exceed 48 ft-lbs, the pressure plate fingers begin to draw inward and consequently the engagement point becomes lower. This makes shifting harder and may cause you to grind the transmission on the hard, 2nd-3rd shift, or when the fluid hasn't been bled particularly well.

The flywheel is 74 ft-lbs on the third pass, per the FAQ, and the driveshaft coupler is 65 ft-lbs. I suspect uneven driveshaft coupler torque is at play here, or that your guy didn't pay attention to where the washers go on the driveshaft coupler, as identified here:

https://www.revshift.com/shop/flex-disc-install.php

It you had a problem with your pressure plate or flywheel, those problems would've been evident at lower RPMs and would probably prevent you from going above 3000 RPM without some serious shaking.

06vmike
07-21-13, 11:21 PM
i can feel shaking from a little over 1k RPM but by the time i get to 2.5k rpm and up its bad i have not dared to bring it much above 3500 rpm since the clutch went in it just feels so bad. also i can be sitting in my driveway with the clutch pressed in and the car in neutral i will rev it just a little bit and i can feel the shaking so im not even moving and i can feel it. so thats why im not sure if it really has to do with the coupler i think something wrong with the clutch install i will be bringing it back to the tranny shop this week to have them look it over any ideas of what i should tell um to look for or at?

JFensty
07-22-13, 10:43 AM
I would think if its shaking that bad, the cause would be obvious when they get in there. Check the balancer as mentioned before. I guess it could be a misfire also. Any check engine light? Check plug wires??

06vmike
07-22-13, 12:11 PM
Ya im thinking its got to be something with the clutch install it was running smooth till they replaced the clutch and flywheel after I picked it up I could tell it was bad but I was gonna give it 100 miles to see if it breaks in but no luck

JFensty
07-22-13, 07:45 PM
Fwiw, my ls7 swap had no issues. I did not balance the flywheel and clutch. I have minimal vibes close to the 2400-2600 rpm range, but many have a similar issue with and without the ls7 clutch.

06vmike
07-22-13, 11:05 PM
i really just wish there was a garage around me that knew anything about LS cars it sucks up here in maine.

WesH8398
11-22-13, 08:40 PM
Could I bump this for a follow-up please? OP - did you figure out the vibration(s)?