Main Support Beam Replacement

Main Support Beam Replacement

Removal Procedure

1. Block the wheels of the axle.
2. Support the axle using jack stands.
3. Drain the air pressure from the air springs.
4. Remove the height control valve link from the valve.




5. Remove the following components from the spring hanger:

* The rebound bolt (4)
* The locknut (1)
* The washers
* The spacer tube (2)
* The rebound roller (3)

6. Raise the rear of the frame far enough in order to remove the load from the main support beam.




7. Remove the U-bolt locknuts (3) and the washers.
8. Remove the following components:

* The U-bolts (1)
* The bottom pads (4)
* The top pad (2)




9. Remove the locknuts (4) and the washers that connect the cross channel (1) to both of the main support beams (3).
10. Lift the cross channel off of the main support beam using jacks.
11. Remove the main support beam assembly.

Installation Procedure

Important: The Delrin liner must be positioned on the top side of the main support beam.


1. Position the main support beam on the axle seat with the main support beam center dowel pin. Pilot the main support beam into the hole of the axle seat or the spacer plate.





Important: Do not tighten the U-bolts at this time. Position the torque rod mounting bolts of the spring seats toward the front of the vehicle.


2. Install the following components:

* The top pad (2)
* The U-bolts (1)
* The bottom cap (4)
* The washers
* The locknuts (3)




3. Lower the air spring and the cross channel mounting bolts into the main support beams (3).

Notice: Refer to Fastener Notice .

4. Install the washers and the locknuts (4) that connect the cross channel (1) to the main support beam (3).

Tighten the locknuts in 37 Nm (50 lb ft) increments to 330 Nm (243 lb ft).

5. Lower the frame in order to ensure that the spring hangers engage the main support beam.
6. Refill air into the system.
7. Center the tip of the main support beam between the spring hanger legs.

Important: Do not exceed the specified torque on the U-bolt locknuts.





8. Tighten the U-bolt nuts.

Tighten the nuts in 37 Nm (50 lb ft) increments to 394 Nm (291 lb ft).

9. Hit the top of the U-bolts using a hammer. Retighten the U-bolt nuts.

Tighten the U-bolt nuts in 37 Nm (50 lb ft) increments to 394 Nm (291 lb ft).




10. Install the following components in the hangers:

* The rebound bolt (4)
* The spacer tube (2)
* The rebound roller (3)
* The washers
* The locknuts (1)

Tighten the rebound bolt locknut to 82 Nm (61 lb ft).

11. Unblock the wheels.
12. Inspect the alignment after installing the new main support beams.