Rear Diff fluid

[AnthonyJMacc]

I'm going to change my rear diff fluid. On Alldata it shows two different fluids, gear oil and rear differential clutch fluid. Do these fluids need to be mixed before filling the diff or is there another port for both fluids?

 

[94cruiser]

It is my understanding they go to two different ports.

Pro Tip:
Open the intake / pour in fluid port first. (you do not want to drain the fluid and then learn that you are having problems opening the top hole)

 

[a200qa]

Be careful changing the clutch fluid. According to the service manual, the clutches need to be cycled using the tech II as part of the service.

And as mentioned earlier, there are two completely different systems with different oil - the differential, and the slip control hydraulic clutch system. The latter is called "differential clutch oil"

Differential Clutch Oil Replacement

• Removal Procedure
  • Raise and support the vehicle. Lifting and Jacking the Vehicle
  • Clean the area around the rear axle fill plug.
  • Place a drain pan under the vehicle.
  • Differential Clutch Cover Plug(1)В»Remove
  • Rear Axle Housing Filler Plug Gasket(2)В»Remove
  • Allow the oil to drain completely.
• Installation Procedure
  • Clean and inspect the drain plug gasket (2)and replace if necessary.
  • Rear Axle Housing Filler Plug Gasket(2)В»Install
  • Refer to Component Fastener Tightening Caution.
  • Differential Clutch Cover Plug(1)В»Install and tighten25 N·m (18 lb ft)
  • Differential Clutch Cover Plug(1)В»Remove
  • Rear Axle Housing Filler Plug Gasket(2)В»Remove
  • Check the fluid level. If necessary, fill the differential to the bottom of the fill plug hole with the recommended fluid. Adhesives, Fluids, Lubricants, and Sealers Approximate Fluid Capacities
  • Clean and inspect the filler plug gasket (2)and replace if necessary.
  • Rear Axle Housing Filler Plug Gasket(2)В»Install
  • Differential Clutch Cover Plug(1)В»Install and tighten25 N·m (18 lb ft)
  • Perform the clutch system bleed procedure. Rear Differential Hydraulic System Service Fill/Bleed
  • Lower the vehicle.

Rear Differential Hydraulic System Service Fill/Bleed Procedure​

The rear differential hydraulic system service bleed is used to remove air from the system, check for proper system and solenoid function, and determine if full pressure can be achieved at the apply piston. Any time a rear differential hydraulic line is disconnected or any repairs are made, this procedure must be performed.

• Connect scan tool and check the rear differential clutch control module for any DTCs and perform repairs as necessary. The scan tool may not allow the hydraulic system service bleed if certain DTCs are present.
• Raise vehicle. Refer to Lifting and Jacking the Vehicle .
• Remove the fill plug. Fill the Rear Drive Clutch fill hole to the appropriate level with the appropriate fluid. Refer to Differential Clutch Oil Replacement, Approximate Fluid Capacities, and Adhesives, Fluids, Lubricants, and Sealers.
• Install fill plug. Lower vehicle.
• Ignition ON.
• From the scan tool menu, select Rear Differential Clutch Control Module, then select Control Functions, then Rear Differential Hydraulic System Service Bleed.
• NOTE
  Note
  The Rear Differential Clutch Control Module can run this procedure. If this step does not pass, repeat procedure from step 2.
  NOTE
  Note
  Status will change to “Complete” when done.