Mechanics

Differential Replacement

How to Remove a Rear Axle Differential Assembly

The rear differential axle assembly on your vehicle is a device that employees gears which transmit torque and rotation to the rear wheels of the vehicle. Power from the engine passes through the transmission which is attached to a driveshaft. The driveshaft then turns the gears in the differential which drives the rear wheels and makes the vehicle move. Although it doesn’t happen often, the rear differential can go bad requiring replacement. Most commonly, the differential will make a grinding noise from bad bearings, or if there is a bad or damaged gear, there can be a grinding noise.

Regardless, if it needs replacement, the job can be done at home with common tools. Please note that if the vehicle is a 4wd, the axle ratio must be the same as the front differential. Otherwise, one axle will spin faster than the other causing a binding and other problems. Additionally, vehicle speed sensors located on the transfer case will think the vehicle is skidding or spinning and cause the ABS to actuate, or on vehicles with automatic 4wd, the computer will engage the system.

Before we begin start with the car on level ground with the emergency brake on and the engine off. Always lift the car by the manufactures recommended instructions and secure the car with jack stands. Be sure to have plenty of clearance to work under the vehicle. Also, we will be dealing with transmission fluid, gear oil, and brake fluid so be sure to wear protective clothing, eyewear and gloves. Disconnect the negative battery cable before you start to avoid electrical system damage.
 

Tools Needed to Complete this Job

1. Hydraulic floor jack

2. Jack stands

3. Ratchet and sockets

4. Wrench set

5. Pry bar

6. Electrical tape

7. Line wrench set

8. Gear oil

9. Brake fluid

10. Shop towels
 

Instructions

Step 1 - Park the vehicle on a flat, firm surface.

Step 2 - Disconnect the negative terminal of the battery.

Step 3 - Block the front tires so the vehicle can’t move.

Step 4 - Using a hydraulic jack, lift the vehicle on its frame or where the manufacturer’s recommended location and secure the vehicle with quality jack stands. Do not lift it from the axle.

Step 5 - Place quality jack stands under the axle to hold the axle’s weight when removing it.

Step 6 - Remove the tires to eliminate weight.

Step 7 - Next, remove the drive shaft from the differential. It is held in place with U or mounting bolts that hold a universal joint to the differential. Remove the nuts-bolts from the u-bolts and carefully pry the u-joint away from the differential.

Step 8 - Take electrical tape and wrap it around the universal joint so the end caps don’t come off, and slid the drive shaft from the transmission and place it out of the way.

Step 9 - Next, you will need to detach the brake line that is attached to the axle housing. Usually, it is held in place by a steel tab. Use a line wrench to prevent damage to the fitting.

Step 10 - Once the brake lines are disconnected, you must stop the brake fluid from draining out of the system. A rubber cap or plug works well for this.

Step 11 - Check the differential housing for any wiring. Many vehicles have speed sensors that are attached to the housing. Disconnect the wiring and remove the sensor if you plan to reuse it.

Step 12 - Remove the shocks from the axle.

Step 13 - Detach the emergency brake cables from the union at the cable junction, or remove the brake drums and disconnect the cable and housing from the backing plate.

Step 14 - Now that everything is detached, locate the large u-bolts that attach the leaf springs to the axle assembly. The u-bolts will wrap around the axle and push through a mounting plate. Using a ½ in drive ratchet, loosen and remove all the nuts on both sides of the axle so you can remove the u-bolts. (Note: Remember, the axle assembly is very heavy. Make sure you have it properly supported.)

Step 15 - At this point, the axle is loose from the vehicle. However, to remove it, you might need to lower the leaf springs. The leaf springs are mounted to the vehicle’s frame. Select which is easier for you to access, front or rear leaf spring retaining nuts from the mount.

Step 16 - Once the nuts are removed, the bolt that holds the leaf mounting bracket, the shackle, need removed. Most times you will need a punch to tap them out due to corrosion. Be careful at this point because once the bolts are removed, the axle’s weight will drop to the jack stands you placed under the axle. Make sure they have little room to travel. Remove the bolts and allow the leaf springs to lay on the ground.

Step 17 - Once both sides are down, take a hydraulic jack, lift the axle so the jack stands can be removed and slowly lower it to the ground one side at a time. Once both sides are down, you can slid the axle from under the vehicle.

Step 18 - Replacement is the reverse of removal. (Note: Remember, your old brake shoes, hardware, and wheel cylinders are still attached to the old axle. You may want to save them or reuse them with the replacement axle).

If further assistance is needed, our certified car repair technicians are ready to answer your car questions. Also, gain manufacturer specific instructions and information by clicking - Auto Repair Manual

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AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-08-16)