Upper Arm

Upper Arm





Removal and Installation

CAUTION: Suspension fasteners are critical parts because they affect performance of vital components and systems and their failure can result in major service expense. New fasteners with the same part number or an equivalent part must be installed if installation is necessary. Do not use a replacement part of lesser quality or substitute design. Torque values must be used as specified during reassembly to make sure of correct retention of these parts. Orientation of the fasteners is also important on all rear suspension arms. Make sure the fasteners are installed in the same direction as they were in when removed.

1. WARNING: The electrical power to the air suspension system must be turned off prior to hoisting, jacking or towing an air suspension vehicle. Failure to do so can result in unexpected inflation or deflation of the air springs, which can result in shifting of the vehicle during these operations. Failure to follow these instructions may result in personal injury.

If equipped, turn the air suspension service switch to the OFF position.





2. For reference during the installation procedure, measure the distance from the lip of the fender to the center of the wheel hub with the vehicle in a static level ground position.

3. WARNING: If equipped with fire suppression system, depower the system. For important safety warnings and procedures, refer to Fire Suppression System.

With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Maintenance/Service and Repair.
4. Remove the wheel and tire assembly.

5. CAUTION: Do not use excessive force when removing the pivot bolt and flag nut on the right upper suspension arm-to-axle bracket. Damage to the brake line can occur.

Remove the upper arm-to-axle bolt and flag nut.
^ Discard the flag nut and bolt.
^ To install, tighten to 90 Nm (66 ft. lbs.).

6. Remove the upper arm-to-frame bolt and the upper arm.
^ Discard the nut and bolt.
^ To install, tighten to 150 Nm (111 ft. lbs.).

7. WARNING: If equipped with fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System.

NOTE: The rear suspension upper arms are interchangeable from side-to-side with "FRONT" and "OUTBOARD" stamped on the side of the arms for positioning during installation.

NOTE: Before tightening the fasteners, use a suitable jack or jack stands to raise the suspension until the distance between the lip of the fender and the center of the wheel hub is equal to the measurement taken in the removal procedure.

To install, reverse the removal procedure. If equipped with fire suppression system, re-power the system.