Wheels & Tires, Chassis Groundout & Exhaust System
Wheels and Tires1. Make sure the front wheels are centered on the rotor hub pilot and the rear wheels are centered on the rear drum pilot by using the Rotunda Runout Gauge, 007-00014 to check wheel and tire assembly runout.
NOTE: Special attention should be given to vehicles equipped with aftermarket aluminum wheels.
2. If incorrect wheel and tire assembly runout is found, loosen the lug nuts, rotate the wheel and tire assembly and carefully retighten the lug nuts finger tight.
3. Recheck the wheel and tire assembly runout while rotating the wheel and tire assembly. If the runout is okay, torque the lug nuts to 100 ft.lbs. (136 N-m). If runout is still incorrect, service as required.
Body to Chassis Groundout
1. Raise the vehicle on a hoist and make sure the mounting bolts from aftermarket seats and safety belt anchors are not grounded to the frame, service as required.
2. Check to make sure the running boards are not grounded to the frame, service as required.
3. Make sure the exhaust system is not grounded to the frame, service as required.
Exhaust System
1. Check to make sure an exhaust bind-up condition is not present by using the following steps:
a. Road test the vehicle to determine if a "drone" noise is present each time the transmission shifts from one gear to the next between 0 and 65 MPH (0 and 105 km/h).
b. If "drone" noise is present, apply the parking brake, depress the brake pedal and brake torque engine to simulate condition. The "drone" should appear around 1800 to 2000 RPM.
c. Remove the exhaust system hanger in front and behind the muffler.
d. Repeat Step b. If "drone" is gone, loosen the "Y" pipe at the exhaust manifold and the muffler.
e. Reposition the exhaust system upward to eliminate stress on the two (2) hangers. Retighten the "Y" pipe to specification.
NOTE: On 1987 vehicles, remove the front hanger bracket from the cross member. Knock out the existing retainer bolts from the hanger. Reinstall the bracket with longer bolts and add 1/4" to 1/2" stack of washers to each bolt between the bracket and cross member. This will make sure the rubber isolator is in a neutral position.