[Pete32500]

Differential fluid change is pretty easy. The ongoing debate is the service interval. I have been doing diff fluid change every 60,000 miles. Fluids look pretty good but there is a lot of metal shavings on the drain plug magnets. This is pretty normal but you want to do it at reasonable interval and clean the plugs to make room for more shavings. Interestingly Infiniti tells you to change fluid every 20,000 miles if you pull a trailer, drive in dusty conditions or drive with a top carrier. Pulling trailer makes sense to me. The other two…not so sure about that.



Fluids that Nissan/Infiniti requires:

Front: SAE 80W-90 GL-5 or API GL-5 differential oil, capacity 0.75 liter

Rear: SAE 75W-90 API GL-5, capacity 1.75 litter

Obviously, it calls for Nissan genuine or equivalent. Years ago I spent some time researching it and selected Mobil 1 75W-90 Synthetic Gear Oil (2 Quarts) and Valvoline High Performance 80W-90 Conventional Gear Oil (1 Quart) both from AutoZone and this is what I have been using since then.

You will also need a transfer pump that attach directly to the standard oil quart bottle. And 4 Nissan diff plugs gaskets. Now this is a confusing part… The part number I purchased from a local Infiniti dealership 5 years ago is 11026-4N200. On main Infiniti parts site it says this is the right part. However on all other dealers parts sites it says this is not the right part and there is no way to find the diff gasket. I used them and they fit perfectly so I just think this is a problem with the dealer websites. More interestingly the washer now costs $5 per piece. For a crush washer! This is just outrageous…Anyway, you will also need a breaker bar, torque wrench that you can set for 35Nm and a 10 mm hex bit socket.

Rear diff:

• Drive the car to warm up the differential fluids. They are very thick and drain much better when warm.
• Drop and remove the spare wheel/tire to get access. No car lifting is required once you do that. Make sure you are parked on level surface for proper fluid fill.
• Break loose fill plug first (good practice as you don’t want to drain fluid to realize you cannot open the fill port). Remove the plug (red circle on the picture below) and see how much fluid leaks out. Should be not much as this should be your proper level.
• Remove drain plug (blue circle on the pic below). Capture all fluid. Remove old crush washers from both plugs, clean plug from metal shavings the with steel wool 0000 grade to remove any caked dirt on the plug flange where the washer sits, clean the port in aluminum diff housing where washer sits. Install a new washers on both plugs.
• Once fluid stopped dripping, install the drain plug with new washer and torque to 35Nm.
• Measure how much fluid came out. The same amount should get in (assuming you had no leaks and whoever put fluid there before did it as required).
• Install transfer pump on the first bottle and start pumping. Once done open new bottle, and continue the process. I was able to put 1.65 liter before fluid comes out. The same amount drained out so I was happy with this.
• Insert fill plug with new washer and torque to 35Nm.

Front diff:

• Drive the car to warm up the differential fluids.
• This is much tougher access. Drain and fill plugs are on different sides of the front differential. You will find them as they are the only plugs for 10 mm hex bit. For easier access you will need to jack up the driver’s side. Put stands under the frame.
• Break and remove the fill plug first.
• Remove drain plug. Remove the stands and lower the vehicle. Let it drain. Capture all fluid. Remove old crush washer, clean plug from metal shavings the with steel wool 0000 grade to remove any caked dirt on the plug flange where the washer sits, clean the port in aluminum diff housing where washer sits. Install a new washer on the plug.
• Once fluid stopped dripping, Lift the vehicle up and put stands. Install the drain plug with new washer and torque to 35Nm.
• Measure how much fluid came out. The same amount should get in (assuming you had no leaks and whoever put fluid there before did it as required).
• Install transfer pump on the bottle and start pumping with the vehicle raised. Once you pumped about 0.7 liter you will have to lower the vehicle to get proper level. Remove stands, lower the vehicle. Pump remaining 0.1 Liter or so. It is tight but can be done. Good lights and a mirror helps out. I was able to put 0.85 liter and as much came out. Interestingly it is more that Infiniti says in the spec sheet. The same amount drained out so I was happy with this. Once fluid level is good insert the fill plug. You will need to jack up the vehicle one more time to put a proper torque on the fill plug.

Just few notes. Always put stands and choke wheels (kind of obvious). Double check you torqued all the plugs. Pay attention to these washers. There are often hard to see on the plugs. You need to remove the old one before you put a new one. Drive and look for leaks. All in all it took me 4 hours. Rear was super easy. Front was time consuming with jacking up and dropping the vehicle multiple times.