REMOVAL & INSTALLATION
- If equipped, remove the hub cap/wheel cover.
- Many GM W-Body vehicles use styled wheels with cosmetic covers over the wheel retaining nuts (also called lug nuts). Some models may use bright-finished metal caps, others may use a black plastic cap. Use a deep socket to unscrew these cosmetic covers.
- With the vehicle still on the ground, use a deep socket and a suitable breaker bar or ratchet to break loose, but do not unscrew the lug nuts.
- Raise and safely support the vehicle.
- Remove the wheel lug nuts.
- Since the tire and wheel assemblies were originally balanced as an assembly on the vehicle and since many professional tire shops may spin balance a tire and wheel assembly while mounted on the vehicle (so the brake rotor and hub are also included in the balance computation), a tire and wheel assembly should always be installed in the same location as removed. Mark the location of the tire and wheel to the hub. Many technicians will chalk the end of the topmost wheel stud and place a another chalk mark on the corresponding wheel opening. In this way, the tire and wheel assembly can be installed in the same relationship as when removed.
- Remove the tire and wheel assembly.
- Clean the wheel nuts, studs and the wheel and rotor mounting surfaces.
- Install the tire and wheel assembly aligning the locating marks made at removal.
- Tighten the wheel lug nuts by hand until they are snug. Then tighten the nuts in a 'star-shape' sequence, as shown in the accompanying figure, and torque to specification. Improperly tightened wheel lug nuts could eventually allow the wheel to come off while the vehicle is moving, possibly causing loss of control, personal injury and property damage.
- Tighten the lug nuts finger-tight. Then tighten in sequence to 100 ft. lbs. (140 Nm). Use of a torque wrench is important. Aluminum wheels will distort under uneven wheel lug nut pressure. Unequal torque can also distort brake rotors, causing uneven brake wear and pulsations in the brake pedal.
- Install the hub cap, if equipped. Install the lug nut cosmetic covers, if equipped.
- Lower the vehicle. With the vehicle on the ground, recheck the wheel lug nut torque.
General Motors says that penetrating oil has not been found to effective in removing tight wheels. However, if it is to be used, it should be applied sparingly to the hub surface only.
Excessive force such as hammering the wheel or tire can also cause damage. Use a rubber mallet to lightly tap the tire's sidewall. Sometimes wheels can be difficult to remove from the vehicle due to foreign material or a tight fit between the wheel center hole and the hub or rotor. These wheels can be removed without damage as follows:
- Tighten all wheel nuts on the affected wheel, then loosen each wheel nut two turns.
- Lower the vehicle to the floor.
- Rock the vehicle from side to side as hard as possible using one or more person's body weight to loosen the wheel, and/or rock the vehicle from DRIVE to REVERSE, allowing it to move several feet in each direction. Apply quick, hard jabs on the brake pedal to loosen the wheel.
Inspect the tread for abnormal wear, check for nails or other foreign material embedded into the tire. To check for leaks, submerse the wheel assembly into a tub of water and watch for air bubbles.
Wheels must be replaced if they are bent, dented, leak air through welds, have elongated bolt holes, if wheel nuts won't stay tight, or if the wheels are heavily rusted. Replacement wheels must be equivalent to the original equipment wheels in load capacity, diameter, rim width, offset, and mounting configuration.
A wheel of improper size may affect wheel bearing life, brake cooling, speedometer/odometer calibration, vehicle ground clearance and tire clearance to the body and/or chassis.
Check runout in all directions (up and down, in and out) using a dial indicator. For aluminum wheels, maximum runout is 0.030 in. (0.762mm) For steel wheels, the specification is 0.045 in. (1.143mm). If the wheel causes a vibration and tire balance does not solve the problem, replace the wheel.