Mechanics

CHEVY

2008 Chevrolet Impala

Shakes or Wobbles problem
2008 Chevy Impala 6 cyl Front Wheel Drive Automatic 40000 miles

Very noticible vibration in car at speeds around 55-65 mph. Starts to fade after that. Sometimes accelerating will make it go away slowly but it always comes back at those speeds
Avatar
Philbo
July 31, 2010.




EI07266 - Vehicle/Tire Vibration, P275/55R20, LT245/75R16, P265/70R17, P245/70R17, P285/45R22, LT265/75R17- Diagnostic Information to Reduce Vibration Concerns
TECHNICAL SERVICE BULLETIN
Reference Number(s): 07-03-10-013D, Date of Issue: November 24, 2008
Affected Model(s): 2007-2009 GM Passenger Cars and Light Duty Trucks (including Saturn); 2007-2009 HUMMER H2, H3; 2007-2009 Saab 9-7X; with any of the following Tire RPOs; - QSS (P275/55R20); - QIZ (LT245/75R16); - QAS / QAN (P265/70R17); - QJM / QJP (P265/70R17); - QPR (P245/70R17); - QVL (P265/70R17); - QST (P285/45R22); - QXT (LT265/75R17)
Supercedes: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 07-03-10-013C (Section 03 - Suspension).

Related Ref Number(s): 07-03-10-013, 07-03-10-013A, 07-03-10-013B, 07-03-10-013C, 07-03-10-013D
ARTICLE BEGINNING
SERVICE INFORMATION
Some customers may comment on a vehicle/tire vibration.
Diagnostic Information
Based upon feedback from dealers, GM engineering has made the following recommendations: Before performing any repairs, duplicate the customer's concern AND test drive the vehicle for 16-24 km (10-15 mi) to properly warm up tires, and remove any temporary flat spots. Refer to Corporate Bulletin Number 03-03-10-007E.
Prior to taking any Road Force Variation (RFV) measurements, it is important to clean the inner wheel surface and remove any large stones from the tire tread. If the tire and wheel assembly is 1-10 lbs greater than GM guidelines for RFV, tire-to-wheel match mounting per Document ID # 1579478 should be attempted. Tire and Wheel Balancing Guidelines-Off Vehicle, refer to Document ID # 1579474, for on-vehicle balancing, refer to Document ID # 1579476.
Road Force Variation (RFV) guidelines can be found in SI. Refer to Information on Tire Radial Force Variation (RFV), Bulletin Number 00-03-10-006E.
If all assemblies can be balanced and RFV readings are within GM Guidelines, runout measurements should be taken to further assist in diagnosis.
If the tire is condemned, all findings (including Position on vehicle, out of balance, RFV and Runout) must be documented on the R.O. And Global Tire Warranty Return form (except Saab).
After installing a new tire, perform a Road Force Variation (RFV) test again to make sure the new tire assembly is within guidelines.
Remember that heavy-duty pickup trucks may vibrate when not under a load.
Refer to Corporate Bulletin Number 08-03-10-004A for GM guidelines on balancing weights. There is a maximum limit of 5 oz per flange.
Take measures to avoid flat-spotting by occasionally moving the vehicle while in storage, prior to delivery.

Dave H
Jul 31, 2010.


AD