AZvetteman

I have been getting a pulsating (occurs at a frequency of like once per second) like vibration that is only felt in the seat (dont feel it on the steering wheel)... feels like the movement is more up and down rather than side to side. This is only felt at speeds of about 60 to 80 MPH. I have the Z06 Motorsport replica wheels 18in front and 19in rear. Here is the timeline of this:

- Bought car used with stock wheels and stock run flat tires ... didnt notice this vibration but I only had the stock stuff on a couple of weeks and I may have been too giddy about owning my first vette anyways for me to notice it
- Bought the taller Z06 wheels and obviously the tires thus have less sidewall. First drive with new wheels had alot of wheel shake, etc. Had the road force balancing done the second time and the tech told me he could see some imperfections in the wheels but they balanced fine and he said this is somewhat normal and "within specs". The car drove much better with the second balance and any remaining minor vibrations, etc. I just decided to live with as I assumed it was partially due to lack large of sidewall/roads.
- I was doing about 90% city driving on far from perfect roads for over a year. I did notice this vibration on the occasional highway drives.
- Now I have moved and do about 75% highway driving and they have gone and put rubbarized asphalt on on the concrete highways and this vibration has been driving me crazy since overall the roads are so smooth now and its not hidden at all within all the road vibrations.
- I needed new tires on the rear and due to the lack of selection in 19in I stepped down from 295/35 to 285 /35 and thus even a little smaller sidewall. I specifically asked them to check for any flat spots or anything out of whack and again they balanced fine and this time they said they didnt see any issues. The vibrations are now worse with these tires.

So, in my mind here are the possible scenarios:

- Vibration was there when I bought it but didnt notice it due to the narrower and taller sidewall on the stock wheels.
- Perhaps these wheels were defective as the balancing tech seemed to have suggested and I should have sent them back even though they did balance ok.
- I have hit an occassional road hazard but nothing big at all in my opinion ... maybe I did tweak a rim

An interesting side note is the dealer said my rear rotors are "welded" on the hub and asked if this car was previously up North ... its always been in Arizona. But then again, they thought they found flat spots in one of my tires but that was probably incorrect as the vibration still occurs with new tires.

Could anything else be causing this pulsating like vibration. Maybe drive shaft not balanced ??? Maybe rotors are way unbalanced due to the "welding" ??? Any other ideas ???

It seams its still most likely just the wheels based on the timeline but I am afraid if I go buy new wheels I mights still have this issue. What would you do since apparently this is going to be hard to troubleshoot ???

FYI ... I am also thinking of steppind down to 18in in the rear again anyways as I want a little more sidewall again since its unfortunetly primarily a commuter car at this point.

Thanks in advance ...

JoshVette

Mine was doing the same a while back after I french kissed a curb......

It was the wheel bearing. Mine was making a surging noise, sounds like what you described though and was more noticeable at higher speeds.

vett_girl

Sit back and enjoy it

z06cab

Vettgrl..I thought you were going to ask if Midamerica sells that option!!LOL

BAMF AE

Vette Girl.....um......Eventhough you already have a vette, would you like to go for a ride in mine

JoshVette

vett_girl

Red Gump

wheels may be out of round. did you buy them used? if your car was tracked in the past, one of your hubs may need to be replaced but you shouldn't notice that going straight unless it's reeeeally shot.

JoshVette

Mine was really bad,.......dang and I just got it fixed too......

JoshVette

My wheel was out of round and it hopped/bounced something awful....

Sounds like the wheels bearings. Got mine fixed and it hasn't done it since.

AZvetteman

Bought the wheels new from WCC and I have been in contact with them but understandably they cant do much a year and half later. They are willing to sell me replacements a bit cheaper than normal but again am worried there is a chance it wont be the fix.

I am not hearing any noise ... just feeling the vibration ... huuummm

TOOGECKO

Just had that conversation with a female coworker at lunch about my Blackberry. It's the life-lemonade, silver-lining view on things !!!

Armadillo

Suggest you (or a mechanic) use a dial gauge to check the wheels before you do anything. This should tell you if they're out of round. If not, it could also be a bad shock or tread separation. Check the tires by running your hand around the flat part of the tread. You should be able to feel a slight "lump" if there's a tread separation. Check shocks for signs of any leaking fluid. Since you feel it in the seat of your pants, it's most likely in the rear.

0EG@EnglandGreen

Ummm.... BOB???

99quicksilver

It could be the bushings on either end of your torque tube.

Llamar Walden Automotive in Atlanta has a great aftermarket set.

Send Rob Walden an e-mail....

mailto:lwa409@bellsouth.net

Flying Ace

I have a similar problem.

After the new tires were put on, I had the alignment done. The tech said almost all of my adjusting nuts were loose!! Also both of my fronts were off in camber/toe-in.

He made it right.

Now I have a pulsing/droning sound like you describe at highway speeds of 70mph+. Especially in sweeping turns!!

I wonder if my wheel bearings are going as well after running the way it did without the fronts being adjusted properly??

mrgil

AZ Go back to the balancing shop and get the Hunter tech guy to check for runout... Specs say .032max but thats Mine ran out .014 and it sook like H**l finally had them match high spot tire to low spot rim and rebalanced down to 11 lbs road forceand it is 80% better
all my other wheels run at 4lbs or less.
Some of these guys justdon't know how to use the equipment.
mrgil