2000NemeSS

iTrader: (2)

Ok, kinda lost. Never had a vibration issue I couldnt resolve. LS1 car with a 6 speed. Car has 98k on the odometer. I didnt notice like a certain day or anything it started happening, but it did seem to happen on my first set of wheels with drag radials. I had some c6 wheels with drag radials, driving them home the first day I remember they drove great, then one day I noticed it really had a bad vibration above 55mph that shakes the seats and floor, so i figured it was in the rear somewhere, rebalanced the tires, no difference. Ive been through 3 different sets of wheels and tires. Now I have racestars with drag radials and still have the vibration. Narrowing it down, not the wheels or tires due to same vibration on all sets used. not in the front end because steering wheel doesnt vibrate. Could it be the driveshaft? the car does have superior axles so bending one doesnt seem real likely. Its not RPM related, only speed related... could someone give me some ideas of what it could be other then driveshaft? btw u-joints checked out ok... only notice is the backlash in the pinion is quite a bit, but its always been that way, feels just like an out of balance tire... please help

blade2222

your driveshaft might be out of balance.

fasteddy

Vibrations suck!

WHen you say its not RPM related do you mean its not dependent on the powertrain?

I always try to separate first ..... powertrain or chassis.

If you're going 55 (your speed) and put it in neutral and coast do you still have the vibration?

If so....then it likely wheels, rotors or bearings. If its these then its usually easier to find and cheaper to fix.

If its powertrain.....could be lots of things.....but its good to eliminate the powertrain first.

ra3psd

I have been chasing a vibration for a year, had u-joints changed and driveshaft balanced twice. Found out that the main shaft on the transmission was bent. Apparently this is not that uncommon. Had the shaft checked while the tranny was undergoing rebuild due to 2nd gear synchro going out. Mine didn't start until about 70-75mph. Hope this helps.

LS6427

iTrader: (2)

Hey man, I have a vibration issue too.

If I also have a bent main shaft on my tranny......and that's causing the vibration.....will putting it in neutral while doing 50-60mph make the vibration go away. Then putting it back into DRIVE will make it vibrate again....?

.

ra3psd

Mine did not go away whether the clutch was in or out. The vibration was always there. My mechanic put the shaft on a V block and found it was 3-4 thousands out. Doesn't take much to cause the vibration.

2000NemeSS

iTrader: (2)

My vibration is still there whether its in neutral or in gear

2000NemeSS

iTrader: (2)

Also, talkin to some other guys, one thing I noticed, when i bought the car, it had a leaking wheel seal when I bought the car, replaced it about a year ago, well its leaking again... good indication I have an axle issue on the right rear...

fasteddy

I'm not a rear end expert (if its not a girl) but I've seen if the axles wear down they can leak right through a good seal......and create noise and vibration.

Easy enough to inspect......good luck.