Vibration at 80mph
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Instructor
Joined: Oct 2011
Posts: 211
Likes: 5
Vibration at 80mph
09 Base MN6 LS3. I've got a recurring vibration that happens when approaching 80 mph. Happens around 78-80. Around 85 it's shaking so bad that both front fenders are visibly moving/shaking. I've had both front's road force balanced. Jacked up both sides and spun the rims. Visibly inspected, do not detect any symptoms of out of round tire or bent rim. Also had it aligned at the same time the fronts were balanced. Not sure where do go next? Thoughts/ideas? Thank you.
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
09 Base MN6 LS3. I've got a recurring vibration that happens when approaching 80 mph. Happens around 78-80. Around 85 it's shaking so bad that both front fenders are visibly moving/shaking. I've had both front's road force balanced. Jacked up both sides and spun the rims. Visibly inspected, do not detect any symptoms of out of round tire or bent rim. Also had it aligned at the same time the fronts were balanced. Not sure where do go next? Thoughts/ideas? Thank you.
There was a poster that had the same problems and had the tire rebalanced with the road force machine with very low numbers.
He wound up trying a simpler spin type balancing job and cured him of all vibrations.
Worth a try....
Safety Car
Joined: Nov 2007
Posts: 4,433
Likes: 873
From: Bay Area CA
Wheel bearing? Bad Rotor?
Also, did you encounter the vibration after the wheel balance? Spinning tires on the car will not detect a slightly bent rim, it needs to go on a machine.
I bent a rim, but visually was fine. Threw it on a balancer and it was off.
I had a vibration/humming noise at 80 mph from a bent rim.
Also, did you encounter the vibration after the wheel balance? Spinning tires on the car will not detect a slightly bent rim, it needs to go on a machine.
I bent a rim, but visually was fine. Threw it on a balancer and it was off.
I had a vibration/humming noise at 80 mph from a bent rim.
Last edited by Mike's LS3; Jul 28, 2016 at 11:38 AM.
Intermediate
Joined: Feb 2015
Posts: 37
Likes: 3
From: Oregon
09 Base MN6 LS3. I've got a recurring vibration that happens when approaching 80 mph. Happens around 78-80. Around 85 it's shaking so bad that both front fenders are visibly moving/shaking. I've had both front's road force balanced. Jacked up both sides and spun the rims. Visibly inspected, do not detect any symptoms of out of round tire or bent rim. Also had it aligned at the same time the fronts were balanced. Not sure where do go next? Thoughts/ideas? Thank you.
Drifting
Joined: Feb 2014
Posts: 1,418
Likes: 267
From: Pontiac Quebec
-a brake rotor will cause a vibration only when braking not normal driving unless cracked or something.
-in 15yrs working as a tech I have yet to solve a vibration with a wheel bearing (unless it was falling off)
-I would say either bad balance or bad tires. Also make sure the tpms isn't broken and flapping around inside the tire.
-in 15yrs working as a tech I have yet to solve a vibration with a wheel bearing (unless it was falling off)
-I would say either bad balance or bad tires. Also make sure the tpms isn't broken and flapping around inside the tire.
