Diagnostic Procedure
1. Interview the Customera. Understand the customer's description of the noise and of the conditions under which it is heard.
b. Road test the vehicle with the customer to fully understand where, how, and when the noise occurs.
2. Duplicate the Noise Concern
a. Drive the vehicle around for at least 15 minutes to warm-up and exercise the frame joints so that any frame noise is more likely to be repeatable in the garage or on the road.
b. Identify the conditions in which the noise is repeatable. Does the noise occur:
^ While parked and turning the wheels lock-to-lock?
^ Only when driving?
^ While going straight over bumps?
^ While on a lift with the suspension unloaded?
^ Only when the brakes are applied?
c. Identify the general location of the noise. Can you "feel" the noise in the floorboard or the steering wheel? Refer to Figure 9 for likely locations for the noise.
NOTE:
USE CHASSIS EARS AND/OR A STETHOSCOPE TO DETERMINE THE LOUDEST POINT OF THE NOISE. IF THE NOISE IS REPRODUCIBLE WHEN STATIONARY, PUT THE VEHICLE ON A DRIVE-ON LIFT AND "FEEL" FOR ANY MOVEMENT OR VIBRATION AT THE JOINTS.
3. Inspect Frame Bolts For Proper Installation Torque
Inspect and tighten all front end components which bolt to the frame to confirm that they are at the proper torque (refer to the Repair Procedure section of this article for proper torque requirements). This includes, but is not limited to:
^ radius arm bracket bolts
^ axle pivot bracket bolts
^ transmission crossmember bolts
^ spring tower bolts
4. Inspect the Frame Rivets
Inspect all riveted frame and suspension components in the general area of the noise for loose or improperly seated rivets.
NOTE:
TAP THE RIVETS WITH A SMALL HAMMER. WHEN A RIVET IS NOT INSTALLED PROPERLY IT WILL MAKE A DIFFERENT SOUND THAN A "SNUG" RIVET.
^ Service identified rivets according to the procedure listed in the Repair Procedure section.
5. Test Drive the Vehicle
Road test the vehicle again to duplicate the concern. If the noise is still present. proceed to the next Step.
6. Test Joints to Locate Noise
^ Use a small pry bar as a "wedge" between components suspected of causing the noise. By pounding the wedge into a joint or behind a bracket the noise should change or be eliminated if the noise is coming from that location.
NOTE:
USING A STETHOSCOPE, OR CHASSIS EARS, WILL HELP TO IDENTIFY ANY NOISE CHANGE.
^ If the source of the noise is identified, proceed to the Repair Procedure section.
^ If the source of the noise has not been identified by this Step, investigate other non-frame or suspension sources and/or proceed to the next Step.
7. Service the Vehicle
a. If the noise has been identified, proceed to the specific component section in the Repair Procedure.
b. If the noise source has not been identified, refer to Figure 9 for general noise locations, operating conditions and number of occurrences. Proceed with repairing the identified components.