GROUP: Wheels & Tires
DATE: April 23, 1999
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 22-02-94 REV. A, DATED OCT. 21, 1994, WHICH SHOULD BE REMOVED FROM YOUR FILES AND NOTED IN THE 1994 SERVICE BULLETIN MANUAL (PUBLICATION NO.81-699-95054). THIS IS A COMPLETE REVISION AND NO **ASTERISKS** ARE USED TO HIGHLIGHT THE CHANGES.
This bulletin involves diagnosis and correction information for vehicles with a smooth road high-speed vibration or shake condition.
POLICY: Information Only
Visual Inspection of the vehicle is recommended prior to the initial test drive. Put the vehicle on a hoist and inspect the following items:
Test Drive the vehicle, in the as received condition, at the complaint speed on a smooth road surface with all accessories turned off. Correct any obvious safety related items identified during the Visual Inspection prior to the Test Drive. It is essential to the diagnosis that the repair facility has identified a smooth road and uses it for the entire diagnosis. A smooth surface will reduce the vehicle response to road inputs and allow the diagnosis to concentrate on the rotating components. If the vibration condition has been corrected due to replacement of component(s) return the vehicle to the customer. If the vibration problem is still present make the following checks:
ON CAR TIRE/WHEEL ASSEMBLY RUNOUT
After your initial Test Drive, correct any deficiencies that the initial Visual Inspection identified. Test Drive the vehicle, if the vibration condition has been corrected due to replacement of component(s) return the vehicle to the customer. If the vibration is still present and it was determined that the vibration is not driveline related proceed to the On Car Tire/Wheel Assembly Runout procedure.
Tire/Wheel Match Mounting is a technique used to reduce radial runout of the tire and wheel assemblies. Excessive runout is a source of ride complaints and Match Mounting is a method of reducing runout.
TIRE/WHEEL MATCH MOUNTING
WHEEL BORE PILOT DIAMETERS
HUB WHEEL PILOT DIAMETER
HUB WHEEL PILOT RUNOUT
WHEEL MOUNTING SURFACE LATERAL RUNOUT