'94 Z28 vibration/wobble (Page 1/1)
n7vrz AUG 20, 10:27 AM
I have a front end vibration that turns into a wobble at 45-60 mph. After 60 it is a vibration again.
I have jacked up the front and tried grabbing the tires to check for movement and I didn't get any that I could feel. While I had it up in the air, I rotated the tires to see if I could hear unusual noises from the bearings. Used my stethoscope and had none that I could hear.
Had the tires rebalanced with no change in front end vibration.
Rotated tires and still have the front end vibration.
Went to different shop and had both done again. Still no change.
Bought new tires. No change.
I was there when the new tires were installed on the rims and at the balancing machine. They are not out of round. The rims are not bent. The tire tread is straight so there is no squirming.
The brakes don't pulsate so the rotors aren't warped.
A while back I needed a seal changed and while my mech had the car in the air I inspected all the rubber suspension components I could find. They all seemed to be good. I know they can look good and still be bad but I'd rather exhaust everything else before I start changing the suspension rubber.
No leaks or even evidence of past leaks on the shocks. Shocks seem good. Pushed down heavy at all four corners and they didn't bounce. Acted normally. Came up. Settled. Done.
Pulled the drive shaft to check for bad u-joints and that the balance weight was still there. They are both fine. No looseness, 'notchy' feel, etc. Nice, smooth movement. The balance weight was still attached and no obvious place where another could have been but wasn't.
I seriously doubt that the tires have cord separation or overlapping. As the vibration is the same with two different sets of tires. Happens at the same speeds, etc. It is always felt in the steering wheel and seat. That doesn't change if the tires are rotated front to back.
So, anyone with suggestions on the vibration cause?
carnut122 AUG 21, 08:17 PM
Inner tie rods?
n7vrz AUG 21, 09:55 PM

quote
Originally posted by carnut122:

Inner tie rods?


Steering is nice and tight. I'll check this out anyway.
BrittB AUG 24, 09:02 AM
Engine mounts?
n7vrz AUG 24, 12:11 PM

quote
Originally posted by BrittB:

Engine mounts?



I have a friend that has a lift in his garage. Tuesday we are putting the car in the air so we can check mounts and suspension components and have room to work.
n7vrz SEP 15, 05:14 PM
Okay, it took a while because of other things that cropped up, but it went on the lift finally.
We couldn't find any mounts, rubber bushings, etc. that were bad or going bad. Yes, a lot of them had some cracking due to age. But we were under it with pry bars trying to get things to move more than normal and couldn't find anything wrong.
I can't just keep throwing money at it replacing stuff that 'might' fix it. Although that is more than likely what will happen anyway.
I've already done this:
rebalanced the tires
rotated the tires
replaced the tires
checked the tires for out of round and squirming
checked for bent rims
checked driveshaft u-joints
checked driveshaft for balance weight (it was there)
jacked up rear end and ran drivetrain to check for bent axle (they're both good)
jacked up front end and tried to move tires for bearing check (good there also)
inner tie rods were previously suggested and they also checked out good
tesmith66 SEP 16, 06:31 AM
Check the lower ball joints (if you haven't already).
n7vrz SEP 16, 06:24 PM
swapped hubs side to side and no change.
n7vrz SEP 20, 01:22 PM
Put in new hubs. 'Wobble' is gone. A very slight vibration is still there but noting nearly as bad as what it was. I can easily live with that little vibration.
avengador1 SEP 24, 03:08 PM
"The brakes don't pulsate so the rotors aren't warped."

But did you measure the lateral runout of your rotors? this is actually how you will know if the rotors are warped.

Read near the bottom of this article.
http://collision.alldata.co...be_safely_turned.htm

[This message has been edited by avengador1 (edited 09-24-2014).]