C3 Underbody Clunk
Thread Starter
Intermediate
Joined: Nov 2010
Posts: 49
Likes: 0
From: Grand Forks ND
C3 Underbody Clunk
This is driving me nuts. I have a clunk in my 1982 Vette. It seems to be just under the divers seat when accelerating at a normal rate from a dead stop. It occurs just a second or two into acceleration. I can actually feel it also. I have had it checked at two shops including the chevy dealership. They say everything is tight and don't know what it is but they are not old car specialists. I have replaced all u-joints, shocks, and many suspension parts. Can anyone help?
Race Director
Joined: Dec 2005
Posts: 13,515
Likes: 12
From: Fisher, IL
U joints in the driveshaft and half shafts?
Might jack up the rear, stick it in N and manually spin the tires to see if there's any slop somewhere or maybe you can hear the noise better that way.
Other than that I have no clue... maybe something in the trans?
Might jack up the rear, stick it in N and manually spin the tires to see if there's any slop somewhere or maybe you can hear the noise better that way.
Other than that I have no clue... maybe something in the trans?
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
Here's another possibility....
Check engine mount on left (driver's) side.
Under acceleration the motor will "torque" twist clockwise (looking forward from driver's seat)
It could be exhaust touching on body, or trans fouling on tunnel.
Look for scuff marks or gouged fibreglass where contact may have occured.
Regards
tom
Check engine mount on left (driver's) side.
Under acceleration the motor will "torque" twist clockwise (looking forward from driver's seat)
It could be exhaust touching on body, or trans fouling on tunnel.
Look for scuff marks or gouged fibreglass where contact may have occured.
Regards
tom
Racer
Joined: Jun 2007
Posts: 294
Likes: 0
From: Nanty Glo PA
Yep, what redwing said. Check carrier mount and snubber bushing. The bottom of the snubber may look good but its the top side you can't see that will go bad. Reach your fingers up in there along either side and see if that hidden doughnut has been compromised or missing. HTH
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
I had a clunk that I could not locate either. Turns out it was a missing bolt holding the transmission mount to the transmission. Well hidden until I got up under it with someone putting the transmission in and out of gear. Just a thought.
