driveshaft vibration

[Gongshow]

My friends 92 gt has driveshaft vibration at higher speeds. The car is lowered, would that cause it to vibrate? It has the stock shaft. If anyone has an aluminum shaft for sale shoot me a pm.

[SN95N/A]

What did he do to this car before it started with this vibration?

[Gongshow]

Well we picked it up Saturday night so its new to him. I was thinking maybe the driveshaft out of balance or the front u joint needs replaced wanted to get opinions

[SN95N/A]

I would check u joints..loose tranny mount possible I have heard the dogbone can cause vibration if someone removed it its a dampner so could cause vibrations.

[Black Horse]

If you see nothing obviously wrong (u-joints, mounts, pinion angle of the car has been lowered, etc.), index the driveshaft 90 degrees and see if it makes a difference. Sometimes it can be a phasing issue. It can also be a bent or twisted shaft too if the car had been launched hard.

[redfirepearlgt]

You mentioned it was lowered. You may also wish to revisit the pinion angle as well.

[Black Horse]

3 degrees of pinion angle is what I try to set them up to.

[Gongshow]

Thanks fellas ill pass it along.

[Dirtyd0g]

If you look at the driveshaft it has a paint dot on the yoke, the output shaft of the transmission has one as well, the pinion of the rearend if never rebuilt has one as well. Align those.
Alan

[akagreg3]

my buddy just went through all this http://www.stangbangerz.com/forums/showthread.php?t=82906 it ended up being 90% the drive shaft.