Exhaust/Vibration problem
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 3,284
Likes: 0
From: I just killed your thread Redneck AZ
Exhaust/Vibration problem
I get an occasional cyclical vibration from time to time in my Vette. Starts at about 55 on straight roads, but really feel it when I let off the throttle going down hills. I noticed when I put the vette in neutral most of the vibration seems to go away.
Recently installed a HT383 GM crate motor and installed 2004R with 3:70 gears.
I also fab'd up a 2 1/2 exhaust with an H-pipe (located just behind the tranny cross member) with Flowmaster 50's (these have a fair amount of resonance).
I'm almost thinking it's my exhaust causing the vibrations, everything is mounted via straps (leather or some sort of material) so it should be somewhat isolated from the car.
I'm wondering if the H-pipe is not located in the proper location and causing some sort of weird harmonic vibration. Should I just eliminate it?
As you can see there's a lot of new stuff on this car and diagnosing can be difficult.
Recently installed a HT383 GM crate motor and installed 2004R with 3:70 gears.
I also fab'd up a 2 1/2 exhaust with an H-pipe (located just behind the tranny cross member) with Flowmaster 50's (these have a fair amount of resonance).
I'm almost thinking it's my exhaust causing the vibrations, everything is mounted via straps (leather or some sort of material) so it should be somewhat isolated from the car.
I'm wondering if the H-pipe is not located in the proper location and causing some sort of weird harmonic vibration. Should I just eliminate it?
As you can see there's a lot of new stuff on this car and diagnosing can be difficult.
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
Sounds like tailshaft issues....
or driveline angles at uni-joints.
I have a vibration that starts at 45mph and disappears at ~50mph.
I haven't found time to sort my problem out yet.
When installing my TKO600 trans, I couldn't get it mounted up high enough due to trans tunnel clearance issues.
I subsequently do not have any angle at my rear uni-joint (tailshaft to diff pinion)
In your situation, check the angles at both front and rear unijoints of tailshaft. They should be typically between 0.5* min and 3* max, and they should be equal but opposite at front and rear.
There's a lengthy thread in this forum....
http://forums.corvetteforum.com/show....php?t=1908437
You may just need to add a spacer to the rear trans mount to correct the vertical alignment.... or it may even be lateral (sideways) alignment causing your problem.
or driveline angles at uni-joints.
I have a vibration that starts at 45mph and disappears at ~50mph.
I haven't found time to sort my problem out yet.
When installing my TKO600 trans, I couldn't get it mounted up high enough due to trans tunnel clearance issues.
I subsequently do not have any angle at my rear uni-joint (tailshaft to diff pinion)
In your situation, check the angles at both front and rear unijoints of tailshaft. They should be typically between 0.5* min and 3* max, and they should be equal but opposite at front and rear.
There's a lengthy thread in this forum....
http://forums.corvetteforum.com/show....php?t=1908437
You may just need to add a spacer to the rear trans mount to correct the vertical alignment.... or it may even be lateral (sideways) alignment causing your problem.
Last edited by OzzyTom; Apr 6, 2008 at 10:02 PM.
