Initial Inspection and Diagnostic Overview

Wheels And Tires

Inspection and Verification

WARNING: A vehicle equipped with a Traction-Lok differential will always have both wheels driving. If, while the vehicle is being serviced, only one wheel is raised off the ground and the rear axle is driven by the engine, the wheel on the ground could drive the vehicle off the stand or jack. Be sure both rear wheels are off the ground.

WARNING: Do not balance the wheels and tires while they are mounted on the vehicle. Possible tire disintegration or differential failure could result, causing personal injury and extensive component damage. Use off-vehicle wheel and tire balancer only.

Be sure to follow the warnings when carrying out the inspection and verification.

Road Test
Verify the customer concern by carrying out a road test on a smooth road. If any vibrations are apparent, go to Noise, Vibration and Harshness Diagnosis.
To maximize tire performance, inspect for signs of incorrect inflation and uneven wear, which may indicate a need for balancing, rotation, or front suspension alignment.
Correct tire pressure and driving techniques have an important influence on tire life. Heavy cornering, excessively rapid acceleration and unnecessary sharp braking increases tire wear.

Tire Pressure Monitoring System (TPMS)
The optional tire pressure monitoring system (TPMS) has the ability to monitor the air pressure of all five tires. The tire-mounted pressure sensors transmit signals to the TPMS module by using the valve stem as an antenna. These transmissions are sent approximately every 30 seconds when the vehicle speed exceeds 32 km/h (20 mph). The TPMS module compares each tire pressure sensor transmission against two pressure limits-low and high. If the TPMS module determines that the tire pressure has exceeded the low or high limit, the TPMS module communicates on the SCP network to the vehicle message center, which then displays a warning message.
Replacement tires must follow the recommended:
- tire sizes.
- speed rating.
- load range.
- tire construction type.
Use of any other tire size or type can seriously affect:
- ride.
- handling.
- speedometer/odometer calibration.
- vehicle ground clearance.
- tire clearance between the body and chassis.
- wheel bearing life.
- brake cooling.
New wheels need to be installed when vehicle's wheels:
- are bent.
- are cracked.
- are dented.
- are heavily corroded.
- are leaking.
- have elongated wheel hub bolt holes.
- have excessive lateral or radial runout.
It is mandatory to use only the tire sizes recommended on the tire chart attached to the vehicle. Larger or smaller tires can damage the vehicle, affect durability, and require changing the speedometer calibration. Make sure wheel size and offsets match those recommended for the tire in use.
1. Inspect for signs of uneven wear that may indicate a need for balancing, rotation or front suspension alignment, a damaged tie-rod, or damaged steering components.
2. Check tires for:
- cuts.
- stone bruises.
- abrasions
- blisters.
- embedded objects.
3. Tread wear indicators are molded into the bottom of the tread grooves. Install a new tire when the indicator bands become visible.