i have this wicked vibration that starts when i'm on the highway at about 70 mph. first i need to give you some back ground info

removed t5, rebuilt, installed poly torque arm and transmission mount along with a stock replacement clutch, this is when i noticed the vibration, when it happens if i press the clutch it's still there, so it's driveline vibration, i wanted a centerforce clutch, i installed that, re assembled with everything the same, vibration is there but hardly noticeable i was happy!, well i blew that tranny, all i did was install a rebuilt wc t5 did not touch clutch or bellhousing, and bam same vibration is back, does the tranny moving left to right on the crossmember mount affect that? or just pinion angle?

i installed 4 brand new rims and tires and it's still the same, i'm kinda stumped on this one.

 

have you checked the driveshaft? I had a similar problem with my car. I put a new set of u-joints in and had my drive shaft balanced, and its as smooth as silk now.

 

this is the 2nd driveshaft, it was the same one when the vibration disappeared when i changed the clutch a 2nd time, now it's back, it's gotta be some kind of alignment issue

 

have you checked your pinion angle?

 

no, not sure how i go about doing that