Road Test Procedure
1. Check tire pressures and inflate all four tires to 26 psi.2. Road test the vehicle under the following conditions:
On a smooth road between speeds of 60 and 70MPH for 10 to 20 miles. Occasionally make turns to check for low-level vibration in the steering and/or body.
NOTE:
You must perform the tests under the above noted conditions to "exercise" the tires and eliminate "cold" flat spotting that occurs due to short-period vehicle storage or parking (see Short-Period/Cold Flat Spotting below for detail).
Performing the road tests as specified will also allow you to get an accurate Wheel/Tire Assembly Radial Force Variation (RFV) Measurement.
Tire Flat Spotting Information:
If vibration occurs in a vehicle's steering/floor/seat at highway speeds, the cause may be tire flat spotting. Two types of tire flat spotting may occur; long-period/storage flat spotting and short-period/cold flat spotting. The following are descriptions of both types:
Short-Period/Cold Flat Spotting:
Short-period/cold flat spotting may occur when a vehicle is parked or stored for short periods of time (i.e. overnight parking or airport parking, etc., for up to 3 weeks).
Tires usually recover from "cold" flat spots. Depending on the storage/parking period, tires may require 10-20 miles of driving to recover from a "cold" flat spot. Tires recover faster when the vehicle is driven at highway speeds (60-70 mph).
Long-Period/storage Flat Spotting:
Long-period/storage flat spotting may occur when a vehicle is parked or stored in one location for a long period of time (more than 2 months).
Long-period flat spotting may also be eliminated by driving 100+ miles at highway speeds (60-70 mph).
3. After the road test is complete, determine if the steering and/or body vibration still exists:
A. If the vibration no longer exists, the procedure is complete.
B. If the vibration still exists, balance the front and rear wheels/tires using the appropriate wheel balance adapter kit and procedures (see Wheel Balance Adapter Kit information).