Driveline Vibes Question

[Speedracer7c]

Hey, I just picked up an 89 gt a few weeks ago. The first time I took it on the highway last weekend I got this weird viabration. It seems like its speeds above 55 and only when I let off the gas or push in the clutch. Basically unload the driveline. I checked the universals other stuff thats easy to check. I dont know if its the tranny or the rear end. The rear end doesnt really whine much but then again i dont know what they did when they put the gears in. Any help or thoughts would be appreciated.

 

[BullittAndy]

Search, the reason noone has responded is because problem could have 100 diffeent answers.
Good luck.

 

[BigHairyMonkey]

prob driveshaft/u joint vibes as usual. get an alum d/s and call it a day.

 

[Speedracer7c]

i tried searching with no luck for the actual problem, I thought that if it was a d-shaft or u-joint issue it would be a more consistent viabration. Rather than just when the drivetrain is unloaded.

 

[stang_hp]

I had the same vibes in my 90 LX, it turned out to be my harmonic balancer. There is a rubber seal inside the balancer, look at the front and the back of the balancer,
and if you can see the rubber seal sticking out past the balancer it needs to be replaced.

 

[Speedracer7c]

I had the same vibes in my 90 LX, it turned out to be my harmonic balancer. There is a rubber seal inside the balancer, look at the front and the back of the balancer,
and if you can see the rubber seal sticking out past the balancer it needs to be replaced.

Thanks, I'll check that but I dont know if thats it. It only does it at speeds above 50 or so. So if im going 50 and push the clutch in the engine will drop to idle and it will viabrate. Thanks for the tip though i'll give it a whirl.

 

[stang_hp]

My car was worst from 55 and rolling into the throttle or at high speeds in neutral.

 

[Speedracer7c]

My car was worst from 55 and rolling into the throttle or at high speeds in neutral.

Wow very interesting. I'll definitely be checking it out today when I put my speedo gear in.