Owners of other Acura or Honda vehicles such as the RDX, ILX, TLX, RLX, TL, CL, RSX, RL, TSX, ZDX, NSX, Integra, Pilot, Accord, Civic, Fit, Clarity, CR-V, CR-Z, HR-V, Odyssey, Element  and Ridgeline may also find these DIY instructions to be helpful.

The only fluid that can be used is genuine Honda or Acura VTM-4 which is part number 08200-9003 or 08200-9003A.

The replacement crush washer (or "gasket") sizes and part numbers are as follows: Drain Plug 18mm 90471-PX4-000 and Fill Plug 20mm 94109-20000.

The tools needed to complete the procedure include a small plastic pry bar tool, a 3/8" drive ratchet, a rubber mallet, a new automotive fluid pump, a torque wrench and a used oil catch container.

Some of the symptoms that indicate the VTM-4 fluid should be changed include a judder, shudder, shake or vibration noises from the rear end of the SUV while turning. This is caused by the fluid being contaminated with worn away clutch material.

For the easiest access to the rear differential, I recommend lowering the spare tire.

Open the tailgate door for the cargo area.

Locate the small plastic access cover for the hoist mechanism that lowers and raises the spare spire.

Lift open the rear edge of the cover with a plastic pry bar tool or a flathead screwdriver.

Remove the lug nut wrench (or "tire iron") from the storage compartment on the left side of the plastic cargo area panel.

Place the socket on the lug nut wrench over the hoist shaft.

Rotate the tire iron in the counterclockwise direction to slowly lower the spare tire.

Slide the spare tire over out of the way where you won't trip on it.

Now would also be a good time to check the condition and air pressure of the spare tire. If necessary, inflate it to 60 PSI.

(I didn't want the spare tire cable and block in my way, so I raised it by turning the hoist shaft in the clockwise direction.)

The rear differential's total fluid capacity is 3.0 U.S. quarts. For a drain and fill, the differential requires 2.9 quarts.

So you'll only need one gallon bottle of Honda 08200-9003 VTM-4 fluid. After three rear diff fluid changes, you'll have enough left over fluid to complete the fourth one. Just be sure to keep the left over fluid in one bottle with the cap tightly sealed.

Slide under the rear of the SUV with the 3/8" ratchet, a rubber mallet, a fluid pump, the used oil catch basin and the gallon jug of VTM-4 fluid.

If you are unable to loosen the fill and/or drain plugs that have been over tightened in the past or have corroded from salt water exposure, you can use an electric impact wrench with a 1/2" to 3/8" drive socket adapter.

If you first remove the drain bolt and then are unable to remove the fill bolt, you won't be able to drive the SUV until the fill bolt can be removed to replace the VTM-4 fluid.

Both the fill and drain bolts have "square" holes which are to be loosened or tightened with a 3/8" drive ratchet.

Securely attach the 3/8" drive ratchet to the fill bolt. Loosen it in the counterclockwise direction.

If you are unable to loosen the bolt, carefully tap on the end of the ratchet with a rubber mallet while holding the top of the ratchet in place.

Set the filler bolt and washer aside in a safe place. We will be temporarily re-using the old washer in the future.

Loosen the drain bolt by turning it counterclockwise with the 3/8" drive ratchet.

Once it seems like the pressure has decreased, fully remove the drain bolt.

The part numbers are as follows: Drain Plug 18mm 90471-PX4-000 and Fill Plug 20mm 94109-20000.

Replace the 18mm washer on the drain bolt.

Inspect the magnetic shaft on the drain bolt for any metal shavings or other metal debris. It is normal to see a light coating of fine metal shavings on the magnet.

Clean the drain bolt with a paper towel.

Set your torque wrench to 35 lb-ft and tighten the drain bolt.

The VTM-4 rear differential is known to be sensitive to fluid contaminations. So avoid re-using an old fluid pump that has been used for the transfer case gear oil or the rear differential on a different vehicle.

Insert the hose into the filler hole at the top of the differential.

Continue pumping in the new fluid until you see it start dripping out of the filler hole.

Many DIY'ers choose to replace the fill bolt, drive the vehicle a very short distance and pump in some more fluid.

Temporarily replace the oil fill bolt with the old washer by turning it in the clockwise direction.

Move any tools, the used oil catch container and other items away from the underside of the SUV.

If you placed wheel chocks on the front tires, remove them and release the parking brake.

Take the SUV for a very short drive such as up and down your driveway or around the parking lot.

Remove the fill bolt by turning it in the counterclockwise direction.

Install a new 20mm washer over the fill plug.

You should be able to pump in another 8 to 10 pumps.

Tighten the fill bolt to 35 lb-ft of torque.

Double check that both the drain and fill bolts are tight before moving on to the next steps.

Slide the retaining block through the hole in the middle of the spare tire.

If it can be moved, slowly tighten the hoist shaft until the spare tire feels secure.

Swing the hoist shaft access panel closed and pop it back into place.

Be sure to record the rear differential fluid change in your SUV's service records.

Take the SUV for a short test drive with some slow speed turns. You shouldn't be hearing any strange sounds from the rear of the vehicle.

For more, please check out all of my 2001-2006 Acura MDX DIY Repair & Maintenance Guides.