vibration at 80

i just installed a prothene trans mount and now when i hit 80 it vibrateing pretty bad is this because its lose? suppose to do that? how tight should those bolts be a torque spec would be helpful for the cross member the acutal mounting to the trans and the stud to the crossmember thanks

sounds to me like the driveshaft is the stock steel one. they are well known for vibrating at highway speed. and now you are feeling it more due to the stiffer mount.

get an LS1 shaft or a 1LE

it didnt do it until the mount though so i cant see it being that

if thats what it is, it was always doin it, but the soft stock trans mount covered it up (as its intended to do) and now you have a performance stiff mount on there and it now transfers all that vibration that you couldnt feel before to the frame/car. if you got a buddy with a alum shaft swap that in and go for a ride. that will tell you one way or the other.
the mount is either tight or its not tight. no need to torque it into place. Im suprised you didnt notice all the extra vib.s that are now being transmitted into the car.

hey man you dont happen to have one i could borrow i notice your kinda close think u could help me out

oh, I didnt notice you were that close.
ask and you shall recieve. I have one here that will be perfect for this. its my spare that I will be takin with me to the track incase my LS1 shaft in my car breaks. I'll be here workin on a buddies car tomorrow evening if you want to come by and install it real quick. go hop on 96 and check it out, then come back and swap yours back in. my extra one here has a groove in it from when I was installin a safety loop in my Iroc and didnt have it quite in the right spot. anyways it'll drive fine, but def. wont be any good for launching a car lol. you'll see. email me
irocss85@comcast.net

nm im just gonna pick up a new one i work at a dealer so i got one coming

cool, which dealer? im a tech at sellers pontiac.

bob jennote

Will any aluminum LS1 shaft work? Manual or auto, as long as its a V8? 98 or newer of course..

yup.