Vibration at 70 (not tire balance issue)
03-05-2010, 06:32 PM
#1
Launching!
Thread Starter
iTrader: (5)
Join Date: May 2005
Location: Denton, TX
Posts: 233
Likes: 0
Received 0 Likes
on
0 Posts
Vibration at 70 (not tire balance issue) When I go 70 down the highway (any highway) my car does this weird vibration thing. It's not really bad, like the car's falling apart, but it's noticable. The car didn't always do this.
A while back, I swerved around a car that pulled out in front of me and ended up on the median (bending a couple rims and blowing out a tire). I started noticing it after that. I thought at first that it was the bends in the rims and/or balance issues. But about 2 weeks ago I sold those rims and bought new rims that are in nearly new condition and the car still vibrates.
Also, it's not constant vibration, it comes and goes for about 2 seconds. As in, vibration for 2 seconds, no vibration for 2 seconds. It's bugging the crap out of me. I do alignments at the shop I work at and have a damn good eye for bad alignments and mine doesn't really look like it's messed up (altho I haven't put it on a lift). I'm wondering if it's something else like a ball joint or bushing or something.
And the vibration isn't in the steering wheel, but in the seats. So it leads me to believe it's in the rear suspension. Any ideas?
A while back, I swerved around a car that pulled out in front of me and ended up on the median (bending a couple rims and blowing out a tire). I started noticing it after that. I thought at first that it was the bends in the rims and/or balance issues. But about 2 weeks ago I sold those rims and bought new rims that are in nearly new condition and the car still vibrates.
Also, it's not constant vibration, it comes and goes for about 2 seconds. As in, vibration for 2 seconds, no vibration for 2 seconds. It's bugging the crap out of me. I do alignments at the shop I work at and have a damn good eye for bad alignments and mine doesn't really look like it's messed up (altho I haven't put it on a lift). I'm wondering if it's something else like a ball joint or bushing or something.
And the vibration isn't in the steering wheel, but in the seats. So it leads me to believe it's in the rear suspension. Any ideas?
03-05-2010, 08:11 PM
#3
On The Tree
iTrader: (16)
Join Date: Mar 2009
Location: St. Louis, MO
Posts: 153
Likes: 0
Received 0 Likes
on
0 Posts
you are correct. vib in the seats = rear
check the u-joints for play. they will cause a vibration at a specific speed most of the time. in your case about 70 how many miles on them?
the drive shaft could also be out of phase. has it ever been out of the car?
check the u-joints for play. they will cause a vibration at a specific speed most of the time. in your case about 70 how many miles on them?
the drive shaft could also be out of phase. has it ever been out of the car?
03-06-2010, 11:14 AM
#4
(You have to keep in mind that when these cars were designed, the national speed limit was 55 mph - so it wasn't such a common annoyance at that time!)
03-06-2010, 12:25 PM
#5
TECH Senior Member
If the vibration goes away if you increase/decrease the speed, this is it. You've just hit the natural frequency of the car. All cars do this. The difference is that different cars resonate at different frequencies and higher end cars have suspensions that do a better job of masking it. Unfortunately, our cars do it at around 65-70 mph.
(You have to keep in mind that when these cars were designed, the national speed limit was 55 mph - so it wasn't such a common annoyance at that time!)
(You have to keep in mind that when these cars were designed, the national speed limit was 55 mph - so it wasn't such a common annoyance at that time!)
03-06-2010, 12:47 PM
#6
Welcome to the club. Mine does that too. Not all the time, but usually. Passenger seat shakes violently, like yours. Shocks are new as of this past summer, no change. The rear end was swapped with a lower ratio (from 3.08 to 3.42) in November but it still vibrates at the same speed, so I would think it rules out the driveshaft too.
I'd love to figure out what it is, so if someone finally tracks it down that would be awesome.
I'd love to figure out what it is, so if someone finally tracks it down that would be awesome.
03-06-2010, 05:10 PM
#7
Launching!
Thread Starter
iTrader: (5)
Join Date: May 2005
Location: Denton, TX
Posts: 233
Likes: 0
Received 0 Likes
on
0 Posts
The car has 108K on it and the u-joints are original. They seemed good when I took the driveshaft out last. It has been out of the car on a number of times for doing the clutch.
Trending Topics
03-06-2010, 05:13 PM
#8
Launching!
Thread Starter
iTrader: (5)
Join Date: May 2005
Location: Denton, TX
Posts: 233
Likes: 0
Received 0 Likes
on
0 Posts
I just drove the car a minute ago and noticed that it would do it up to like 75 but I didn't go over that speed. But it does seem to do it harder when you are holding the gas to maintain speed. Like when you're going up a slight incline
03-06-2010, 05:32 PM
#9
Sorry but that's just simply not true. My car, or all the other Fbodies I've been in or driven (10+) do not vibrate at 65-70mph. If your car is vibrating then it has an issue whether its something as simple as wheels being off balance, or warped rotors, or something else.
03-25-2010, 05:21 PM
#10
Launching!
iTrader: (6)
Join Date: Sep 2006
Location: Southeast, Michigan
Posts: 274
Likes: 0
Received 0 Likes
on
0 Posts
Engine mounts and trans mount!
I've been researching this vibration for a while now.
I have a prolly trans mount, so that will be swapped out first for a stock mount.
If that doesnt help, new stock engine mounts will be swapped in.
I've been researching this vibration for a while now.
I have a prolly trans mount, so that will be swapped out first for a stock mount.
If that doesnt help, new stock engine mounts will be swapped in.
03-25-2010, 09:05 PM
#13
On The Tree
iTrader: (7)
Join Date: Sep 2004
Location: Fulton IL
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
Mine does this same thing.. NONE of the other 3 FBodies I have owned have done this. It started doing it (at least noticably) after I put my new wheels/tires/brakes on. They are 19's with a 30 aspect ratio so every little thing is magnified. I do also notice my steering wheel vibrating slightly...not as much as the seats.
I DO have a poly trans mount .... It seems to have a different feel to it than any of my other Fbody M6's. Not sure how to explain that. Seems like the trans is bolted directly to my ***. Im starting to think this is part of the cause of the vibration.
I posted another thread about ( "control arm problem" ) where I notice the rear end acting .... strange. Maybe a bad bushing or something? May be the cause to the vibration.
03-26-2010, 02:17 PM
#14
I have the exact same issue. I am wondering if it IS the poly trans mount. Now that I just spent money on poly engine mounts and a poly torque arm mount. Will that effect anything? Anyone have any issues with the poly engine mounts giving off a vibration?
03-27-2010, 11:33 AM
#15
On The Tree
iTrader: (7)
Join Date: Sep 2004
Location: Fulton IL
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
I noticed a squeak taking off from a stop sign yesterday. Sounded like it was coming from the rear center of the car. Im going to have to check the U-Joints on the driveshaft. Would that cause vibration?
03-27-2010, 12:45 PM
#16
It depends. If your vibration is at one specific speed and goes away when you go faster or slower, the fix is probably to be found in the suspension. If your problem hits at a certain speed and stays with you as you increase speed, then it could be in your drive train.
03-29-2010, 10:55 PM
#19
My friends C5 does this also....
Also dont forget to torque your lugnuts...or at least torque them all around the same torque. If one is tighter than another it puts more pressure on the rotor making it act like the feeling of warped rotors....
It might not do this while driving and only when applying brakes idk but most people dont think about it so just throwing it out there.
Also dont forget to torque your lugnuts...or at least torque them all around the same torque. If one is tighter than another it puts more pressure on the rotor making it act like the feeling of warped rotors....
It might not do this while driving and only when applying brakes idk but most people dont think about it so just throwing it out there.
