Differential Service

Drain and refill the rear differential with fresh synthetic gear oil, replacing the drain plug washer to maintain proper lubrication and extend differential life.

Warnings

Tools required

Parts

• Drain plug crush washer × 1 — Use OEM specification

Fluids

• 75W-140 synthetic GL-5 gear oil — 2.75 qt

Preparation

1. Park vehicle on level ground and engage parking brake.
2. Place wheel chocks in front of the front wheels.
3. Ensure differential housing is cool to the touch.
4. Gather all tools, fluids, and the new drain plug washer before beginning.

Procedure

1. 1

   Raise and support vehicle
   Lift the rear of the vehicle using a floor jack at the rear differential housing or designated rear lift point. Support the vehicle securely on jack stands placed under the rear subframe or axle housing. Ensure the vehicle is stable and level before proceeding underneath.
2. 2

   Locate differential plugs
   Position yourself under the rear of the vehicle and locate the differential housing. Identify the fill plug on the front or side face of the differential housing and the drain plug on the bottom of the housing. Clean the area around both plugs with a wire brush and shop rag to prevent contamination during service.
3. 3

   Remove fill plug first
   Using the appropriate metric socket, loosen and remove the fill plug from the differential housing. Set the plug and its sealing surface aside in a clean location. This step confirms you will be able to refill the differential after draining.
4. 4

   Drain differential fluid
   Position the drain pan directly beneath the drain plug. Using the appropriate metric socket, slowly loosen the drain plug. Once loose, carefully unscrew it by hand for the last few threads and pull it away quickly to avoid the stream of draining oil. Allow the differential to drain completely until the flow stops, which typically takes 5-10 minutes. Inspect the drained fluid for metal particles or unusual debris.
   ⚠Gear oil will flow quickly once the drain plug is removed. Keep hands and arms clear of the drain stream.
5. 5

   Install drain plug with new washer
   Remove the old crush washer from the drain plug and discard it. Install the new crush washer onto the drain plug. Clean the drain plug threads and the threaded hole in the differential housing with a shop rag. Thread the drain plug by hand into the housing until snug, then torque to specification using a torque wrench.
   Torque spec

   Drain Plug41 Nm (30 lb-ft)
6. 6

   Refill differential with gear oil
   Using a fluid pump or transfer pump, insert the pump nozzle into the fill plug hole. Slowly pump 75W-140 synthetic GL-5 gear oil into the differential (approximately 2.4 quarts; verify exact capacity against Chrysler service documentation). If the differential is a limited-slip (Trac-Lok) unit, add the OEM-specified friction modifier additive. The housing is full when oil is level with the bottom edge of the fill hole (begins to weep or drip). Fill to this level regardless of the approximate quantity used. Allow any excess to drain back out, then wipe the fill hole area clean.
7. 7

   Reinstall fill plug
   Clean the fill plug threads and inspect the sealing surface. Thread the fill plug by hand into the housing until snug, then torque to specification using a torque wrench.
   Torque spec

   Fill Plug41 Nm (30 lb-ft)
8. 8

   Lower vehicle and verify
   Remove the jack stands and carefully lower the vehicle to the ground. Inspect the area around both the drain plug and fill plug for any signs of leakage. Wipe the differential housing clean for easier leak detection during the test drive.

Reassembly

1. Ensure both drain and fill plugs are torqued to specification before operating the vehicle.
2. Dispose of used gear oil properly at a recycling center or automotive service facility.

Verification

• Start the vehicle and allow it to idle for 1-2 minutes, then inspect under the vehicle for any fluid leaks around the differential plugs.
• Test drive the vehicle for 10-15 minutes, including turns and moderate acceleration to circulate the new gear oil.
• After the test drive, re-inspect the differential housing for leaks while the vehicle is on level ground.
• Check that no unusual noises or vibrations are present from the rear differential during operation.

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