posted
I recently bought two new Goodyear Eagle F1 GS tires, the stock tires on the 03 SS. Now that I drive it around, the rear end is real loose on turns and the car feels very unstable and out of control at highway speeds, greater than 70mph. I was just wondering if anyone else had this problem when running two brand new tires on the back while having two tires with about 20% tread on the fronts. Thanks for your help.
posted
This does not sound normal to me. Have you checked the tire pressures and that the lug nuts are all tight (to 100 lb-ft)?
Posts: 383 | From: Oakville, Ontario Canada | Registered: Jan 2003
| IP: Logged
posted
yes, I'm running the recommended 30psi in all tires and all lug nuts are torqued to 100 ft-lb. I drove over a really bumpy road the night I got my flat tire...which in turn is the same day I got two new tires for replacements. Have you heard of anyone driving over a rough surface and damaging their suspension? I was only going 20mph max on the smooth parts. Thanks for your reply.
FireChicken
11 Secret Herbs & Spices
Member # 2067
posted
Are the wheels balanced properly? As for driving over bumpy roads and suspension, I know if you go very fast (25+) over dirt roads, over time it will wear out your shocks faster than normal use, however, it should not be an immediate thing. Maybe your differential is having issues?
Posts: 686 | From: Texas: Hullabaloo, Caneck! Caneck! | Registered: Aug 2003
| IP: Logged
posted
Put a couple hundred miles on them. Should go away. Most likey just new tires. Maybe Ken could chime in but I find new street tire to lack grip for a few miles.
Posts: 113 | Registered: Nov 2002
| IP: Logged
posted
All of the wheels were balanced when I got the new tires, even the wheels with the used tires got balanced.
I've put a lot of miles on the tires but they were highway miles. It does seem like the rear end gets way loose when I turn sharply. I guess I might drop it off at the dealer. Thanks for the help.
posted
Try rotating the tires to see if the problem moves to the front. If so, request that whoever installed the tires perform a road force balance. It is MUCH more sophisticated way of balancing, which involves checking the trueness of the wheel itself, and also the tire. Request a printout of your road force results.
Sounds like you might have a bad tire (ie. slipped belt, improperly stored, etc).
posted
It also could be simple as condensation inside teh tire, leaked in from the air compressor. I have found up to a cup of water in my tires after a tire change, depending on the shop. Have the balance rechecked, it should reveal any major problems like that, and check to make sure all of your lugnuts are still at 100 ft-lbs of torque.
-------------------- 1999 Trans Am - Pewter, A4, 3.23's
Stock for now Posts: 471 | From: Justin, in the Great State, Texas | Registered: Sep 2000
| IP: Logged
posted
Sorry for not replying further since my initial reply. I have not been on the board since before Christmas.
Happy New Year, and I hope everyone had an enjoyable holiday.
Here are some further thoughts. You mentioned that this all started after going over some rather nasty bumpy roads.
This can put a lot of stress on the shock absorbers and if one or both of them bottomed out, it can potentially ruin them (especially if you have played around with the bump stops or they are missing). This will result in the car shifting weight too fast going into a corner making it feel unstable. The car will alos bounce and move around on the end with the bad shock absorber(s). You can check this by pushing down on the rear bumper. If the car bounces, the shock(s) are toast. I would suggest that you DO NOT push doen on the rear fenders as you can dent them.
Another thing to check is the drag links for the rear anti-roll bar (part that attaches the bar to the body in the wheel wheel). If one or both of them is/are broken, the car will feel rather loose in a corner. It will feel like you can not hold a line through a corner (ask me how I know this!!).
One other thing to look at is the panhard bar. If it is loose or bent the car will be very loose going around a corner. I highly doubt this is the case though as it would be accompanied by tires/wheels rubbing the body work and there would be a fair bit of banging and rattling at other times.
The other thing to look at is the lower control arm(s) to see if they are bent. This would casue the axle to develop a thrust angle making it unstable in a straight line and make it loose in a corner in one direction and turn in rather aggressively in the other direction due to excessive slip angle at the rear wheels.
Hope this helps. Good luck.
Posts: 383 | From: Oakville, Ontario Canada | Registered: Jan 2003
| IP: Logged
posted
Thanks for the help Bill. I took it to the dealership and had one of the mechanics ride out with me. He looked under the car and made sure the shocks weren't shot. He said nothing was bent or out of place. I had them force balance the tires and they rotated the worn tires to the back and the new tires to the front....The car drives like a dream now. I guess it was just the tires. I'm not all that knowledgeable about cars, so I guess the rule of thumb is to place the worn tires in back or just spend the $1,000 (which a college student like me doesn't have) to get all 4 replaced.
By the way, what is force balancing a tire entail? And how is it different than regular balancing it?
quote:Originally posted by DwarfDump: Thanks for the help Bill. I took it to the dealership and had one of the mechanics ride out with me. He looked under the car and made sure the shocks weren't shot. He said nothing was bent or out of place. I had them force balance the tires and they rotated the worn tires to the back and the new tires to the front....The car drives like a dream now. I guess it was just the tires. I'm not all that knowledgeable about cars, so I guess the rule of thumb is to place the worn tires in back or just spend the $1,000 (which a college student like me doesn't have) to get all 4 replaced.
By the way, what is force balancing a tire entail? And how is it different than regular balancing it?
Thanks for the help.
If you think it was the tires,are the new tires directional? If so were they on the correct side so the rotation is correct? Posts: 5682 | From: Dearborn,Mi. | Registered: Feb 2002
| IP: Logged
posted
Yes, I run the stock Goodyear Eagle F1 GS tires which are directional. That is infact the first thing I checked when the car seemed unstable. All the tires were rotating in their correct directions. Thanks for the help.
posted
Another quick thought - in my package with the BFG KDs they said that the lubricant used in manufacturing takes several hundred miles to dissipate so don't push the tires until they are broken in.
-------------------- 2000 SS Convertible, M6, Onyx Ebony leather, Hurst, Monsoon, 12 CD SLP Options: Syntech, Mats, Fobs, Plaque, Cover. SLP add ons:SS Grille, SLP Lid & K&N, smooth bellows, SLP CAI.... Other Add Ons: TTS LT headers Y Pipe and Cats, TR 220, LS6 Intake, GMMG, ASP underdrive pulley, Hypertech 180 stat, Granatelli MAF, Rapid Motor Sports custom tuning, BMR STB, LCAs, Relocation brackets, Adj. Panhard, Don Goetz bolt on SFCs, Hotchkis springs, Hurst Billet Plus shifter Appearance: FRCs with afterthoughts SS overlays, Mark's Caliper decals on black painted calipers, AR TTIIs (Gunmetal Spokes) with BFG Gforce T/A KDWs...
96 Impala SS Black Flowmasters SSOA, WCA, NAISSO Posts: 3403 | From: Woodcliff Lake, NJ, USA | Registered: Dec 2000
| IP: Logged
Printer-friendly view of this topic
![[Big Grin]](biggrin.gif)
![[Smile]](smile.gif)
