: "HELP" Does your CTS-V "CLUNK"



LS6-CTS-V
05-05-05, 08:26 AM
Between 1st and 2nd at low RPM's, or trying to drive moderately slow does your CTS-V have a clunck or a clinck some where in the drive train. ??????????

It seems like if I try to shift under 3000 rpm it clunks.

CTSV05
05-05-05, 10:03 AM
Yep, it used to.

Now its much smoother, and I don't seem to have the lurch upon lower rpm shifting as I did before either.

But, there are instances where I can hear the backlash, like if I push the clutch in and release pressure on the driveshaft at certain times, but its very minor.

Joey'sVee
05-05-05, 10:52 AM
Yes, I have the clunk. It doesnt bother me too bad though. Usualy I have the radio on so I can't hardly hear it. As long as it doesn't get worse (I got 800 miles on it) I'll be ok.

LS6-CTS-V
05-05-05, 11:01 AM
How did you get rid of the clunk @ sloppy backlash.

my dealer is lame,and will say that the after market stuff is doing it. but after I took off the Pinion Brace,from BRM, it is much more noticeable

cts-v ls6
05-05-05, 05:43 PM
The clunk is related to the dual mass flywheel. Search the forum for posts--there are plenty. The V owners that have replaced the flywheel/clutch/pressure plate [myself included] don't have any clunk.

Dave's V
05-05-05, 09:41 PM
There has also been threads about the pinion support increasing rear end whine or at least transmitting the whine to the chassis.

When I have to replace the clutch, I'll replace the dual mass flywheel. Till then I can live with the clunk.

Also if you let out the gas all the way before you push the clutch in, it won't clunk.

CVP33
05-05-05, 10:38 PM
Mine has a slight clunk in between blowing half shafts. :yup: Good luck.

Vrocks
05-06-05, 12:25 AM
Between 1st and 2nd at low RPM's, or trying to drive moderately slow does your CTS-V have a clunck or a clinck some where in the drive train. ??????????

It seems like if I try to shift under 3000 rpm it clunks.

It will if I don't drive around it. If I keep some load on the drivetrain it almost never occurs.

agion
10-31-14, 01:53 PM
i rectently picked up a 2004 cts-v mine also makes a "clunk" but if i take my foot off the gas then put the clutch in it doesn't make the clunk noise. would that be the dual mass flywheel?

darkman
10-31-14, 03:30 PM
The clunk has several contributing causes. Some of those causes can be eliminated (or almost eliminated) with fresh parts, and at least one cause that can only be eliminated with an aftermarket differential. The stock differential is a limited slip unit with a clutch pack that has a fair amount of engagement slack even when the differential is new. So getting rid of all the clunk can only be accomplished with the installation of another differential. There are at least two popular options available. In addition to the differential there are other components of the drivetrain that contribute increasing amounts to the clunk as they deteriorate. The ones that come to mind include: the oem liquid-filled motor mounts, the spring-loaded dual mass flywheel, the rubber transmission mount, and the driveshaft components that flex.

rand49er
11-02-14, 02:33 PM
IMHO, the OEM diff is 98% of it.

Welcome to the Clunk Club.

Derek5.7
11-04-14, 09:35 AM
My list of clunk elimination jobs, to date, is as follows: rear diff poly bushing install (got mine from Creative Steel and this elininated a HUGE clunk at the diff between shifts, especially when gunning it); motor mount and trans mount poly installs (from Creative Steel) - again tightened things up in the driveline considerably; had an LS7 clutch installed (this eliminated the VERY annoying clunk that was produced by the old, worn-out dual mass flywheel); and finally I am awaiting the return of my driveshaft from Matt Williams (Vodoochicken) who is installing a 30a poly carrier bearing to replace the 160k sloppy, sagging rubber bushing that had my driveshaft flopping around (and clunking) like crazy - apparently this service by Matt will make our driveshafts feel like a one-piece driveshaft if you go with a poly. So the only remaining "clunk" will be the gear-lash assiociated with the rear diff. I have a 3rd generation diff so I'm pretty happy with it and the gear lash isn't that big a deal, in my opinion. Hope this helps. I went on a frenzied rampage to eliminate as much of the clunk in the driveline as I could and I'm hear to say that I've gotten very close to eliminating almost all of it, short of replacing the rear diff w/an 8.8.

mberisha
11-16-14, 06:36 PM
Clunk....it's a V1 badge of honor....plus it's super cool at parades....:duck: