Vibrations on the highway

[95strokerPSU]

I drove home from school today (3.5 hour drive) and noticed that above 70mph I'm getting vibrations that I can fell in my seat. Sounds like it's coming from the back-center of the car, so I'm thinking driveshaft/rear axle area. The only other piece of helpful info I can provide is that I tried taking it out of gear when I felt the vibration, and taking it out of gear made it worse.

Any ideas?
Thanks

 

[slytherin]

Sounds like a universal/'s gone bad either that or your D/S threw a weight.

 

[95strokerPSU]

Stupid question but whats a universal, is it a U-joint? Also what to look for if d/s threw a weight?

 

[slytherin]

Yep universal joint is what you want to check push on the D/S verticaly and/or horizontally if there is play they need replaced. If you threw a weight off the D/S(which would be pretty hard to do) what to look for are marks that look like spot welds that aren't holding anything on. If the D/S threw a weight get an aluminum one= better balance + some weight savings.

 

[95CobraMike]

do new drive shafts come with new u-joints? or do you have to use your old ones over?