Silver Bullet 8150

iTrader: (1)

title says it all, i took my driveshaft off and got it balanced, got an alignment for my car and everything was ok. balanced the tires. anyone have any idea's y my car is shaking between 70-80MPH. no matter if im in 5th or 6th gear the car still shakes at that MPH. please help, im losing my mind with this problem, i cant even drive the damn thing its so bad.....thanks in advanced

poindtj

I used to have a 89 5.0 mustang that did that. ended up being a bad u joint.

poindtj

I assume that you had the U-joints inspected with the driveshaft. I used to have a 89 5.0 mustang that did the same thing and it turned out to be a bad u-joint.

00Streak

I have the same problem but it clears up a bit after 80. I was told that it had to do with the harmonics of our front upper and lower A arms... but i heard that off this board from another member.. so take it for what its worth.......
S

Silver Bullet 8150

iTrader: (1)

i forgot,u-joints were also changed.....

OfficerZ28

Maybe u just get nervous at high speeds and start shakin the steering wheel involuntarily....my .02 :-)

2xLS1

iTrader: (25)

Borrow another set of wheels and tires from another car for a test drive. I have seen tires cause this even though they balance OK.

kossuth

iTrader: (12)

Also is it a steel or aluminum DS??? My S10 does this with the 4.10's at about the same speeds you just mentioned. The reason being was the harmonics and the way the DS was constructed. Steel will begin from my understanding reverberate at about 60-75% of it's critical rotational speed. Just something to think about.

Silver Bullet 8150

iTrader: (1)

Yeah i do have a steel stock driveshaft, so ur saying i have to get a aluminum DS?

2xLS1

iTrader: (25)

I'm pretty sure GM even put out a TSB on the steel D/Ss for that problem. I swapped out a steel one for an aluminum one on a 97 LT1 Aniversary Z that had that problem at 90 mph and it cured his problem. I put in an aluminum D/S out of a 01 T/A. If this is on the car in your sig, how did a 02 WS6 M6 come with a steel D/S? It should be aluminum.

Silver Bullet 8150

iTrader: (1)

ohh ur right it is aluminum, my fault, this is what happens when i post while half asleep

NOBR8KSS

iTrader: (12)

I have the exact same problem...only my car vibrates between 65 and 75 mph. I have changed everything I can think of with the exception of the torque arm (which I will have from LG if they will get off their *** and make them).
Rebalanced the wheels, rotated the wheels, made sure the rotor retainers were removed, installed a Denny's driveshaft, changed the shocks, changed the rear axle, removed / reinstalled the rear brakes...etc. Only thing I haven't done is replace is the torque arm.
The vibration is definitely coming from the rear axle...and it isn't continuous, it phases in and out between 65 and 75 mph. It has remained the same through all of the changes that I made...although it did improve very slightly with the new driveshaft. If the LG torque arm doesn't fix it, I will seriously consider selling my car.
I would suggest you check your pinion angle. I haven't checked mine, but I imagine with as shitty as the stock torque arm is, there could easily be a problem.

Slowhawk

iTrader: (12)

Here is a list of problems I found before on different cars other than DS.

Wrong pinion angle
off balance brake rotors
wheel balance
bent axle's
loose preload on posi unit.

Could be any of these.

Silver Bullet 8150

iTrader: (1)

how do i check the pinion angle, balance the rotors, loose preload on posi unit. is this stuff that i can do, or do i have to bring it to a shop?

samz28

warped rotors = take them off and have them turned for $5 each at some brake-o store. likely if you had an A4 and did brake stand burnouts, but you don't.

those aluminum drive shafts do bend/rip you know? my bro has a bent one. Why i stuck with the steelie. I think it took him a season of track' to bend his. if yours is bent check out a chromoly or carbon fibre (yah right$$) setup.

the rest i think you need a smart mechanic to do, have you hit anything lately? or been dragging and this just came on?

Time2Kill

iTrader: (49)

I have a bad vibration from 85 to about 100.
I've been playing around with my pinion angle and it changes the speed that it happens at. I'd check ur pinion angle.

JRcamaroZ28

iTrader: (41)

I was having vibrations from 75-80+ played w/ the pinion angle and it would just move it around. last night i took off the stock wheels and put on my freshly balanced Drag Radials and 80% of the vibration has gone away. When i get them back later today i'm going to test them out and see if it was a rebalance that was needed. i'm going to play a little more w/ the Pinion angle and i will soon be getting a new CM driveshaft anyways.

JR

samz28

you know what after i took the tire off my car (nail in nitto). well it didn't even penetrate the tire, so we put it back on, and mysteriously it balanced out without a single weight (previously had one small one).

i guess the tires wore into their round-ness with the burnouts lol

so many times people think that its impossible for a BRAND NEW (and especially old) tire to be the culprit when in fact it is. I almost changed out the wheel bearings on my vw. But we went to the used tire store, spent $30 on two new fronts, wasn't the bearings was a tire with a deformed wire or something.

sometimes we take the most obvious in your face things and overlook them. Worth swapping tires with a buddy to check never the less. It's not like that takes too long if you got some stands.

Tom L. Busby

1) Does the steering wheel shake? or, 2) Do you see the side view mirror-image shake?
Just a suggestion to try to narrow it down to front or rear problems.

02 WS6 Silver Bird

EVERYTHING SHAKES, THE WHOLE ENTIRE CAR.