Need help with a vibration

[GTSJERRY]

Hey guys i have a 96 GTS, i have been fighting a vibration for a while, it comes in at about 80 mph and doesnt really get any worse at higher speeds but it is still there, i feels as though it works its way from one end of the car to the other, say from front to back and goes a way for a moment and then starts over again form front to back. I have had all four tires high speed balanced, found left rear hub with excess play, replace hub bearing, had new tires put on rear, still no change, even had a transmission replaced for popping out of gear, didn't change the vibration, and just replaced both rear halfshafts with new and still have not made any differece. Has anyone ever had a problem like this or any idea of what it could be? Any help would be great.
Thanks Jerry

 

[FrankBarba]

hows your rotors?

 

[hemibeep]

do you feel the vibration more through the steering wheel or more through the shifter handle? seems like if it is in the shifter, tends to be driveline(possible driveshaft)
if in steering wheel, front suspension (rotors/hubs)..

also most high speed balancers are closer to 60MPH and may not be balancing at 80MPH.

many times warped rotors can be felt in brake pedal...

 

[Daniel Cragin/DC Performance Inc]

Check your half shafts.

 

[Hisserman]

I assume your high speed balance was a load balance, correct? They should run it up to higher than 80 mph. Was it Hunter equipment?

 

[GTSJERRY]

I think they spin them to 120, but not sure. Front rotors have been replaced too. As for feeling in the steering or shifter it is about the same in both.

 

[Tom F&L GoR]

Good excuse for a dyno day - if it doesn't show up on the dyno, it's in the front end?

 

[PaViper]

Good excuse for a dyno day - if it doesn't show up on the dyno, it's in the front end?

That's a good plan, I like it.....I never thought of seeing if a vibration shows up on the dyno.

 

[Bo knows]

High speed balancing is useless on these cars. Have the tires road forced & balanced on a Hunter GSP 9700. You will thank me after it's done !!

Bo Knows

 

[viper spray]

Check the flywheel. Mine vibrated a little then blew.

 

[PaViper]

I don't think the flywheel would be it unless it did it at the same rpm range all the time

 

[Eric H]

i have a similair issue, i put on my track wheels and it seems to have gotten better, but still slightly there, let me know if you figure it out!

 

[GTSJERRY]

I am taking it to a place that puts it on a type of a dyno used for the diagnosis of vibrations so im hoping they can find something. I will let you know what i find.