For 1990-2009 cars

### Single Speed

The single speed rear axles are made up of the following two main components:

• | The rear axle housing

• | The differential carrier assembly

| The banjo-type rear axle housing carries the weight of the vehicle. The rear axle housing provides a machined spindle surface for the rear wheel bearings. The rear wheel hubs rotate on the rear wheel bearings, allowing the rear axle shafts to float within the rear axle housing.

| The differential carrier assembly performs the following functions:

• | To change the driving force 90 degrees from the propeller shaft.

• | To allow the rear wheels to turn at different speeds.

The differential carrier assembly consists of the following components:

• | The drive pinion

• | The input yoke

• | The ring gear

• | The differential carrier

• | The differential case

• | The side gears

• | The differential gears

• | All related bearings

The complete carrier assembly may be removed from the vehicle without removing the axle housing assembly.

### Two Speed

The two speed rear axle contains two different gear ratios or ranges. The two speed rear axles operate in the same way as the single speed rear axles. The driver selects the range using a control switch on the instrument panel. A shift motor assembly mounted on the rear carrier engages a shift fork which selects the range chosen by the driver. The shift motor assembly is electrically operated. The shift fork will perform the following functions:

• | Slide a collar onto the sun gear of a planetary gear set.

• | Slide the entire sun gear assembly in or out of the gear set.

Two possible gear ratios may come from the same gear axle.

### Tandem

A tandem rear axle increases the amount of payload a vehicle may carry. The tandem rear axle increases the traction factor when both rear axles are locked together. A tandem rear axle consists of the following components:

• | A rear axle front unit

• | A rear axle rear unit

• | The rear axle front unit has a power divider with an inter-axle differential, which sends power to the individual axle differentials. The power divider allows for inter-axle differential action between the two rear axles.

• | The tandem rear axles have the ability to be locked together, providing power to both the rear axles without the inter-axle differential action. The electric or air operated inter-axle differential lock system is controlled by an air cylinder/differential lock assembly. The air cylinder/differential lock assembly is part of the power divider that is mounted to the rear axle front unit differential carrier. The drive controls the electric/air operated inter-axle differential lock system using a differential lock switch located in the instrument panel.

• | All the rear axles have a removable differential carrier. The tandem rear axle operates in the same way as a single speed type of a rear axle.

### Overhaul Dana/Spicer

For overhaul information of the Dana/Spicer® differential carrier assembly, contact the Spicer® Support Line at 1-800-666-8688 or go to http:// www.roadranger.com.

### Overhaul Eaton

For overhaul information of the Eaton® differential carrier assembly or the power divider, contact Eaton® Roadranger® Service at 1-800-826-HELP (1-800-826-4357) or go to http:// www.roadranger.com.

### Rear Axle Identification

For complete rear axle identification information, refer to Rear Axle Identification .

• | For unit repair information of the Dana/Spicer® differential carrier assembly, contact the Spicer® Support Line at 1-800-666-8688 or go to http://www.roadranger.com.

• | For unit repair information of the Eaton® differential carrier assembly or the power divider, contact Eaton® Roadranger® Service at 1-800-826-HELP (1-800-826-4357) or go to http:// www.roadranger.com.

• | For unit repair information of the Rockwell differential carrier assembly, contact the Rockwell Field Support Center at 1-800-535-5560 or go to http:// www.roadranger.com.