CRAZY BAD VIBRATION IN REAR END

[auburn809]

I need help!!! I've got a 97 gt with some minor mods, procharger, tranny, 4.10 gears, so on and so forth. when i get between 90 and 110 the whole car feels like it's going to shake apart. It also makes this god awful noise. only a couple of mods to the rear, like the 4.10 and a posi trac. And running stock height and suspension. has anyone run into anything like this before. And what did you do to correct it. Thanks folks.....

 

[Kilgore Trout]

When you installed the 4.10s was the driveshaft re-installed in the same position using scribe marks to make sure it was re-installed correctly.

My guess is the vibration is from the driveshaft because it was not re-installed correctly.

Was the dogbone removed?

 

[COramprat]

I'm guessing driveshaft related but describe futher when it stated happeing. Is it related to RPM's in any gear or just speed?

 

[BooWFO]

Could be DS. it's an easy thing and cheap thing to rotate.
But
It could be tires.
or it could be a spun bearing on the tloc. Trust me I have one right now and haven't had time to yank the carrier apart and put the new tloc in.
Does it feel like driving on rumble strips? Is it very pronouced on decel?

 

[auburn809]

the vibration is like running over rumble strips and it feels a little more pronounced on decel. i've changed the ds and went to an aluminum shaft. i've changed tailshaft bearings in the tranny and put the spacer on the shaft for the tremec. It happens only at the speed between 90-110 not below or above. thanks guys