Vibration Problem - Unresolved.
Thread Starter
Instructor
Joined: Feb 2006
Posts: 144
Likes: 0
From: Woodlands TX
Vibration Problem - Unresolved.
The Patient: 96 C4 with less than 100,000 miles.
Symptoms:
1. Slight "jerking" while stopping.
2. Vibration and road noise that gets worse as speed increases (and not consistent - more pronounced at times).
3. Hot Wheels (no pun intended). Driver's side hotter than passenger and significantly hotter than the rears.
4. Caliper(s) appeared to move freely.
5. Front suspension appears to be tight without any slack.
6. Tire balance and warped rims have been eliminated - slight scalloping evident on the inside edge of both front tires. Note: Vehicle was aligned within the last year and there has been no trauma (curbs/pot holes) to the vehicle.
Diagnosis: Possible warped rotor
Treatment:
1. Replaced both front rotors.
2. Installed new pads.
Result:
1. Vibration disappeared for a couple of days.
2. Braking felt normal (improved).
3. Road noise persisted but was attributed to the scalloping on the tires.
4. Vibration has returned.
Any suggestions? At this point I am presuming that one of the calipers is binding or I got a bad tire. I did not lube any of the caliper hardware because it appeared to move properly and would just result in a bunch of gunk building up on the hardware from the brake dust
Symptoms:
1. Slight "jerking" while stopping.
2. Vibration and road noise that gets worse as speed increases (and not consistent - more pronounced at times).
3. Hot Wheels (no pun intended). Driver's side hotter than passenger and significantly hotter than the rears.
4. Caliper(s) appeared to move freely.
5. Front suspension appears to be tight without any slack.
6. Tire balance and warped rims have been eliminated - slight scalloping evident on the inside edge of both front tires. Note: Vehicle was aligned within the last year and there has been no trauma (curbs/pot holes) to the vehicle.
Diagnosis: Possible warped rotor
Treatment:
1. Replaced both front rotors.
2. Installed new pads.
Result:
1. Vibration disappeared for a couple of days.
2. Braking felt normal (improved).
3. Road noise persisted but was attributed to the scalloping on the tires.
4. Vibration has returned.
Any suggestions? At this point I am presuming that one of the calipers is binding or I got a bad tire. I did not lube any of the caliper hardware because it appeared to move properly and would just result in a bunch of gunk building up on the hardware from the brake dust
Instructor
Joined: Mar 2009
Posts: 126
Likes: 1
From: Newington CT
Since the vibration returned shortly after you replaced your rotors, I have to ask.
Did you overtighten your lug nuts?
They need to be torqued to 100 ft. lbs. no more, no less.
Overtightened lug nuts warps brake rotors, it's very common.
Did you overtighten your lug nuts?
They need to be torqued to 100 ft. lbs. no more, no less.
Overtightened lug nuts warps brake rotors, it's very common.
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
The Patient: 96 C4 with less than 100,000 miles.
Any suggestions? At this point I am presuming that one of the calipers is binding or I got a bad tire. I did not lube any of the caliper hardware because it appeared to move properly and would just result in a bunch of gunk building up on the hardware from the brake dust
Any suggestions? At this point I am presuming that one of the calipers is binding or I got a bad tire. I did not lube any of the caliper hardware because it appeared to move properly and would just result in a bunch of gunk building up on the hardware from the brake dust
Pro
Joined: Nov 2005
Posts: 602
Likes: 0
From: North Bay Ontario
Try swapping your tires and see if the problem 'moves'. Another warped rotor is possible, from improper torquing as suggested or, if you have a seized caliper piston(s) the intense heat could have caused a premature warping situation. Another possibility is that there is dirt or corrosion between the back of the rim and where the rim seats on the rotor. It's gotta be a tire or a seized piston(s).
Le Mans Master
Joined: Mar 2001
Posts: 7,999
Likes: 14
From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
I think the key is the one side warmer than the other.
Get a pair of rebuilt front calipers, use a hi temp grease on the sliders.
Sounds like the caliper piston is binding or the caliper itself is binding.
Get a pair of rebuilt front calipers, use a hi temp grease on the sliders.
Sounds like the caliper piston is binding or the caliper itself is binding.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
hman1987,
It does sound brake related (presume "hot wheels" mean the mag wheel/rim not the the tire).
Have you tried bleeding the brakes and the ABS unit and using the correct brake fluid (should be DOT-3, not DOT-3/4) and the sequence of bleeding each wheel should be strictly adhered to as per the FSM.
Remember DOT 4 fluid can be thicker and cause pistons (in the calipers or ABS unit) to move more slowly or maybe even hang up).
Also, what tire pressure are you using (suggest 33 psi cold which works great on our 94 with OEM Goodear runflat tires). Sometimes underpressure can in it self create heat in the tire which can be transferred to the mag wheel and thereby the brake rotor.
Lastly, even though you had the alignment done, don't presume it was done correctly and get it re-checked somewhere else by someone else -- sometimes alignments are screwed-up due to equipment failure or the 'cocky factor' (THINK they know how to do it or take short-cuts because they 'know' better).
It does sound brake related (presume "hot wheels" mean the mag wheel/rim not the the tire).
Have you tried bleeding the brakes and the ABS unit and using the correct brake fluid (should be DOT-3, not DOT-3/4) and the sequence of bleeding each wheel should be strictly adhered to as per the FSM.
Remember DOT 4 fluid can be thicker and cause pistons (in the calipers or ABS unit) to move more slowly or maybe even hang up).
Also, what tire pressure are you using (suggest 33 psi cold which works great on our 94 with OEM Goodear runflat tires). Sometimes underpressure can in it self create heat in the tire which can be transferred to the mag wheel and thereby the brake rotor.
Lastly, even though you had the alignment done, don't presume it was done correctly and get it re-checked somewhere else by someone else -- sometimes alignments are screwed-up due to equipment failure or the 'cocky factor' (THINK they know how to do it or take short-cuts because they 'know' better).
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
I've had this issue with my '85 years back.
Turned out the tires were bad somehow. Swapped in a new set and the car became smooth.
If you've excluded the rims and suspension/brakes, can't be much else.
Turned out the tires were bad somehow. Swapped in a new set and the car became smooth.
If you've excluded the rims and suspension/brakes, can't be much else.
Pro
Joined: Oct 2003
Posts: 506
Likes: 12
From: Savannah GA
If you have only had your tires balanced and there is any chance they are part of the problem find a Hunter GSP 9700 road force balancer. Look at the page and you will see what it can do.
I can tell everyone from experience a GSP9700 is the final answer to the tire balancing question.
http://www.gsp9700.com/index.cfm
Vibrations are usually tire related.
Tierods and bearings can cause vibrations to.
A co-workers pickup truck had a brake shudder that a shop finally gave up on. The next place cleaned all the rusty scale off the hub, rotor and wheel and cured the problem. It was the slight thickness variation of the rust. It would change when the wheels were taken off and on to.
JS
I can tell everyone from experience a GSP9700 is the final answer to the tire balancing question.
http://www.gsp9700.com/index.cfm
Vibrations are usually tire related.
Tierods and bearings can cause vibrations to.
A co-workers pickup truck had a brake shudder that a shop finally gave up on. The next place cleaned all the rusty scale off the hub, rotor and wheel and cured the problem. It was the slight thickness variation of the rust. It would change when the wheels were taken off and on to.
JS
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Thread Starter
Instructor
Joined: Feb 2006
Posts: 144
Likes: 0
From: Woodlands TX
The thing is that the problem is inconsistent. The vibration is more pronounced at times. Ir will range from being barely noticeable to being so bad that I am looking for the ejection handles getting ready to punch out. I can stop somewhere and it will switch back to the other end of the continuum. Everything is really clean and "tight". I had her checked out before I bought her and the mechanics at the shop advised me that everything looked great and appeared to have been well taken care of. They put her on the rack and checked the suspension, etc. Other than the usual leaks (which I have fixed and have the scars to prove it) they didn't find anything.
It has to be a tire or a caliper. I saw thread on rebuilding calipers and it looks pretty simple (and cheap). I'll try that first because I just bought rear sneakers and the other woman in my life...lol...might blow a gasket.
It has to be a tire or a caliper. I saw thread on rebuilding calipers and it looks pretty simple (and cheap). I'll try that first because I just bought rear sneakers and the other woman in my life...lol...might blow a gasket.
Last edited by hman1987; Apr 19, 2009 at 11:05 AM. Reason: spellilng
Racer
Joined: Apr 2005
Posts: 408
Likes: 0
If you have only had your tires balanced and there is any chance they are part of the problem find a Hunter GSP 9700 road force balancer. Look at the page and you will see what it can do.
I can tell everyone from experience a GSP9700 is the final answer to the tire balancing question.
http://www.gsp9700.com/index.cfm
Vibrations are usually tire related.
Tierods and bearings can cause vibrations to.
A co-workers pickup truck had a brake shudder that a shop finally gave up on. The next place cleaned all the rusty scale off the hub, rotor and wheel and cured the problem. It was the slight thickness variation of the rust. It would change when the wheels were taken off and on to.
JS
I can tell everyone from experience a GSP9700 is the final answer to the tire balancing question.
http://www.gsp9700.com/index.cfm
Vibrations are usually tire related.
Tierods and bearings can cause vibrations to.
A co-workers pickup truck had a brake shudder that a shop finally gave up on. The next place cleaned all the rusty scale off the hub, rotor and wheel and cured the problem. It was the slight thickness variation of the rust. It would change when the wheels were taken off and on to.
JS
Heel & Toe
Joined: Apr 2009
Posts: 16
Likes: 0
need more input
These can be a real pain. So, it only does this when braking???? I have seen some strange stuff. Check out your rear brakes too. when i bought my vette it had 64K had the same thing going on. put new tire on it was good for about 4 days. Come to find out I started poking around And found just a little play in the steering rack. Not the inner tie rods either. just enough that the rack made a slight knock when i pulled up and down at the inner tierod boot on the drivers side. new rack No shake. hope it's not this. Rack is pretty cheap labor isnt.
Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
At this point, i'm betting its a tire problem. Could be a problem with the steel belt etc. Enternal problem that can't be inspected from the outside but the tire holds the balance. I'd change a tire or two.
Thread Starter
Instructor
Joined: Feb 2006
Posts: 144
Likes: 0
From: Woodlands TX
I haven't done much with this. I am gonna wait and replace the front tires. It has to be bad tire acting up under certain conditions as the severity of the shake varies and is very inconsistent.
To answer a couple of questions.....the problem is most evident at cruising speed....a pretty good shake at times, not bad at others. You can feel it a little at braking but not as bad as you would expect. There is no pull to either side going down the road. The steering feels really tight and I can not find any play in the front end.
To answer a couple of questions.....the problem is most evident at cruising speed....a pretty good shake at times, not bad at others. You can feel it a little at braking but not as bad as you would expect. There is no pull to either side going down the road. The steering feels really tight and I can not find any play in the front end.
Last edited by hman1987; Apr 21, 2009 at 01:48 PM. Reason: grammer
Thread Starter
Instructor
Joined: Feb 2006
Posts: 144
Likes: 0
From: Woodlands TX
Ok, I think I found it. It was not apparent with the engine running but with the engine off, if you move the steering wheel back and forth it will make a "clunk" noise in the rack in pinion area. I presume that one or more the bushings have gone bad (and hopefully not the rack itself). Does anyone know if the bushings require a press to replace? Also, has anyone here been able to get away with replacing the bushing without taking the unit completely out?
Last edited by hman1987; Apr 27, 2009 at 05:06 PM. Reason: More info
