Just hit 18,000 miles and took the day to flush both diffs.
- 10mm hex socket
- Torque wrench
- Transfer pump to pump fluid back in
- Breaker bar or something to break loose the plugs (they are on pretty tight)
- 2-3L of your favorite diff fluid (I used Nismo Motul 75w140)
- Front diff: torque 26 ft/lb fill/drain plugs, 0.65L fluid
- Rear diff: 25 ft/lb fill plug, 39.5 ft/lb drain plug, 1.35L fluid **note this changed from earlier years to later to avoid seal issues from too much pressure
Before I started, I wanted to pre-measure the amount of fluid I was going to need and I wanted to see how much would drain out. A quick makeshift measuring system for input and output fluids:
Start by getting the car lifted up:
Nismo Motul 75w140
After removing the front undertray, you should be exposed to this (where you normally would change your oil). Note the two plugs that take the 10mm hex, one on top (fill) and one on bottom (drain).
You have just enough clearance to get your 10mm hex socket in there with some extensions. Start by removing the fill plug first, then the drain plug. I put a funnel to catch the fluid and drain into our make shift measuring cup.
Ended up draining just a little bit higher than 0.65L:
Clean the drain plug well. The magnet does its job well!
This fluid is the smelliest thing ever.
Replace drain plug & torque to spec. Premeasure your fluid to go back in. I measured 0.65L again rather than let it drip out over the fill plug since my garage has a slight incline.
Use your favorite hand pump to get it back in.
Replace fill plug. Torque to spec. Replace front under tray.
Remove rear tray (the CF one under the transmission). It may be helpful to support with something to prevent it from falling down.
Here is a shot of the rear diff. The top fill plug has my socket inserted and the bottom drain plug is ready to be opened.
Same procedure as the front. Remove top fill plug first. Remove bottom drain plug and catch the fluid. The drain plug has a magnet as well and will be dirty (be sure to clean well).
After draining, I collected about 1.5L:
Note the color (fresh is clear):
Replace drain plug. Torque to spec. Fill using pump. Replace fill plug. Torque to spec. Replace rear under tray.