The differential is one of the more overlooked service items on a BMW. Most cars will go their entire lives without having their differential fluid changed. Let's face it - many only focus on what is under the hood, not buried in the rear of the vehicle.
Changing the fluid in the differential is, in some ways, just as important as changing the oil in the engine. The only difference, besides fluid type, is the interval at which you change the fluid. The differential fluid lubricates the ring and pinion gears that transfer power from the drive shaft to the axles, protecting metal to metal contact. But, in a differential there is no combustion occurring, so the fluid has the potential to last much longer than engine oil.
Changing the differential fluid on a regular maintenance schedule is easy enough and can save you a big headache down the road.
Parts
- (2) Quarts Redline Differential Fluid 75w-90
Tools
- 14mm Socket
- Drain Pan
- Fluid Transfer Pump
Getting Started:
- Jack up the rear of the vehicle evenly on each side and place on jack stands. Please refer to your owner's manual for proper jacking etiquette.
- Upon inspection of the differential you'll notice two hex head plugs. The top plug (1) is the fill hole, and the bottom plug (2) is the drain hole. (Refer to the picture)
- Before draining the fluid, loosen the fill plug on top first. Once the fill plug is loose then you can remove the drain plug. Be sure to have a drain pan underneath the differential before loosening the drain plug; fluid will start to drip as soon as it is loose.
- It will take a few minutes for the fluid to drain out. Once drained replace the drain plug and remove the fill plug.
- Grab the fluid transfer pump and diff fluid. Place the hose labeled OUT into the fill hole, and the hose labeled IN into the diff fluid bottle and pump the whole quart into the differential.
- Pump in around 3/4 of the second bottle or until fluid starts to barely drip out of the fill hole. Replace the fill hole plug.
Replacing differential fluid is a good habit to get into with all RWD/AWD vehicles as it helps prevent failure and keeps money in your pocket.
Capacities
E36 318 differential capacity: 1.2 quarts
E36 BMW 323, BMW 325, BMW 328, BMW M3 differential capacity: 1.8 quarts
