DIY: Rear Differential Oil Change

spearfish25

Well, this is a pseudo-DIY. I didn't take pictures solely because it's entirely straight forward. Here are the steps and part numbers for the things you'll need.

Required items:
Jack and jack stands
Torque wrench
10mm Allen head ratchet attachment
Nissan metal gasket x 2 (38351B) WASHER - 370Z (Z34) 2009+ :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com
Siphon pump (available at Autozone for $10)
GL-5 gear oil, 2 quarts (I used Redline 75W90 synthetic)
Oil collection pan or container (Autozone $10)

Instructions:

1. Jack up the rear of the car and place it on jack stands. I just used the rails where the manual says to place the jack. The metal lip is strong enough to withstand a jack and jack stands that don't have the special grooved attachments.

2. Allow the car to cool so you don't burn yourself when you drain the oil. Place the oil collection pan under the rear differential and locate the drain screw that faces towards the back of the car at the base of the diff as well as the filler screw on the passenger side of the diff. (See Image 1 in the service manual clipping)

3. Using your torque wrench and 10mm Allen head ratchet attachment, loosen the filler bolt first. This will ensure that you can get this screw open to refill the differential BEFORE you empty out the oil (you don't want an empty diff and a stuck filler screw). Once you've ensured you can loosen the filler screw, go ahead and remove the drain screw. I found an articulating joint was helpful to make the ratchet wrench fit better. I broke it loose with the ratchet and then loosened it the rest of the way with the allen attachment by hand to make sure I didn't drop the screw into my oil collection drum.

4. Allow the gear oil to empty completely...give it 10 minutes or so. You'll see it's pretty darn nasty and black. The drain screw is magnetic and you'll likely find a bunch of sludge on it that you can clean off during this time. It's amazing what accumulated in just 3,700mi.

5. Once the oil is drained, place a new metal gasket on the drain screw and screw it back in place. The recommended torque is 25-26 ft-lbs (1 ft-lb makes no difference and is probably less than the precision of the average torque wrench).

6. Next remove the filler screw on the passenger side of the differential (you may have done this already in Step 3). This will give you access for the siphon pump hose. Insert the outlet end of the siphon pump into the differential a few inches so it stays in place.

7. Place the inlet hose of the siphon pump into your fresh container of oil. Start pumping...you'll notice it takes a bit of work to pump the viscous oil up into the differential. While the diff only takes 3 pints (1.5 qts), I pumped a full 2 quarts into the diff and just let the excess run back out and into the oil pan below the car. This ensures that you have the diff filled and accounts for the oil that remains in the pump and tubing.

8. Once the diff is overflowing, you're all set. Remove the siphon hose from the diff and place a new metal gasket on the filler screw. Replace the filler screw and torque it to 25-26 ft-lbs.

9. Clean up the mess and check for leaks.

You've just changed your rear differential oil! Feel free to give a rep point if you found this helpful

Transmission oil change DIY coming in the next week or two (process should be very similar)

Attached Images

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