phirepower

iTrader: (2)

I'm having some issues with my 97 formula firebird, I believe the problem to be routed to the driveshaft. I've owned the car for almost 2yrs, and in them i have replaced the universal twice. The car runs smooth and accelerates hard up until i hit around 90 mph, then the car shakes violently underneath the shifter (6spd). Would it be a good idea to replace the shaft, or are there other possibities for this problem? thanks Dan

YodiBrodi

cheap easy solution is locate stock LS1 al ds and replace. typically under $100. common problem for LT1 cars with even aftermarket steel ds. i know, i paid $225 for scratch built steel ds(i was in a bind), had it balanced 2x and still no good. it was stock length but all other dimensions were diff to GM OE ds. i then paid $125 for LS! al ds shipped to my door and problem solved. i don't know what the issue is, harmonics or whatever, but the cars just prefer aluminum

pddye

iTrader: (14)

I have the same problem around 85-90 then above 95 it is better but the vibration is still noticable even more when i decelerate. I bought a brand new ls1 driveshaft (not the discontinued one) and still have the same problem but not as noticeable still bad tho. i can't figure it out

Hardtop94

iTrader: (14)

had that prob too, the poly tranny mounts make it worse, but switched to a 3rd gen al driveshaft with spicer u- joints and problem solved

Ironxcross

iTrader: (8)

so that explains my whole car shaking like crazy at 110 yesterday..

moserman

iTrader: (7)

if you replace the driveshaft and still have "bucking" issues, then its inside the rear axle, i went through 3 driveshafts and 4 u joints before i noticed this..... just an idea to remember if the problem still exists!!