Tire and Wheel Inspection. GMC Truck GMC C Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC C Pickup - 2WD 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Tire and Wheel Inspection

The tires on all new GM models have a tire performance criteria (TPC) rating number molded on the sidewall. The TPC rating will appear as a 4-digit number preceded by the letters TPC SPEC on the tire wall near the tire size. A replacement tire should have the same TPC rating.


(1)	Hard Cornering, Under Inflation
(2)	Excessive Toe on Non-Drive Axle
(3)	Heavy Acceleration on Drive Axle, Excessive Toe on Drive Axle, Over Inflation

Inspect the tire and wheel assemblies for the following conditions:

•	Unusual wear such as cupping, flat spots, and heel-and-toe wear

(These conditions can cause tire growl, howl, slapping noises, and vibrations throughout the vehicle.)

•	Proper inflation

•	Bulges in the sidewalls

(Do not confuse bulges with normal ply splices, commonly seen as indentations in the sidewall.)

•	Bent rim flanges

By inspecting these characteristics of the tire and wheel assemblies, you may discover the cause of the vibration. The inspection will also provide assurance that the vehicle is safe for road testing.