Hi there,

I'd like to just get this out of the way. I've had some vibration coming through the shifter and clutch pedal in my car. I recently installed an LS Alumin Driveshaft, the vibration persists at highway speeds, 70+

When testing "phase" do you pull the driveshaft out of the transmission and rotate 180* or can you just unbolt it from its straps at the pinion and turn it while it's in the transmission?

THAT is the main question

Secondly, I wasn't having these problems when I pulled out my driveshaft last year to do UJoints, I fear I may have damaged something in my freshly built rear or perhaps in my transmission.

I also have the Tunnel Mounted Adjustable Torque Arm, which I was told I have the proper angle with from Belle Tire, not sure if this is true.

However I played with the driveshaft and the pinion angle.

There is also a pulsing bassy womp sound that is consistent with the vibration at speed.

At this point, I have tried the LS shaft (Which took care of other smaller problems, but still don't feel comfortable at highway)

I've had an alignment, and I've had the (fairly new) tired balanced.

I'm close to being stumped, I was going to go home and spin the driveshaft around, and perhaps try to do pinion angle again.

The rear is completely rebuilt with an Eaton posi, and all new bearings and seals. The car itself only has 45,000 miles

Any help would be great, thanks. I'm beginning to go a little crazy.

 

Also, I've seen suggestions to replace tailshaft bushing and seal, but I cannot find those exact parts on rockauto.

Would that be the input or output shaft? How about the seal for the tailhousing in general? Or is that a repair that can be done on the car?

 

Have you changed the trans mount? Changing to a poly mount from the rubber oem picks up vibrations in an instant that you never new were there.

 

I replaced the trans mount with a new rubber one when I did the TA relocation.

I pulled the driveshaft all the way out of the transmission and did a 180 on her. Haven't been able to take her up to highway speeds yet though. Will update tonight.

When I was playing with it, I didn't notice much if any play from the tailshaft bushing.