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 .

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.

Replacement tires must follow the recommended:

• tire sizes.
• speed rating.
• load range.
• radial 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:

• bent.
• cracked.
• dented.
• heavily rusted.
• leaking.
• wheels having elongated wheel hub bolt holes.
• wheels having excessive lateral or radial runout.

Wheel and tire assemblies are attached by 8 (F250/350) or 10 (F450/550) intergral two-piece swiveling wheel nuts.

If corrosion exists, or the integral two-piece swiveling wheel nut does not rotate freely, install new swiveling wheel nuts as necessary.

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, front suspension alignment, damaged tie-rod or 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.