This is a DIY for a Differential Oil change for a 330i E46.
Time: approx 30 minutes.
Level: Easy
Tools required: Floor Jack, 4 jack stands, (2) can be used, 1/2 Drive Ratchet 14mm Hex
Socket, drip pan, rags, 2 bottles of Differential fluid and fluid pump (I used Redline 75w/90
Diff/transaxle fluid)
1. Jack rear end of car (safely) using jacking points and locate fill and drain plugs.
Drain plug will be the lower plug facing Right Rear Tire, The Fill plug is the slightly higher and facing the sway bar.
IMG_0687 by da94450, on Flickr
IMG_0689 by da94450, on Flickr
2. Loosen the Fill plug first, unsing you ratchet and 14mm hex socket, this will ensure that you will be able to fill after you drain the oil. (If you drain the oil first and your fill plug is stripped or stuck you will be SOL to refill oil and will not be able drive your vehicle)
IMG_0686 by da94450, on Flickr
IMG_0691 by da94450, on Flickr
3. Place oil drip pan under the drain plug and remove the drain plug, while oil is draining you may remove the fill plug, (please do not mix the plugs, even though they are same plug I always return the plug to the same port it was removed from.)
4. Lower car ensuring car is clear of tools and equipment are clear. Lowering will ensure all fluids are drained as car will be sitting at its natural stance. (Have a beer)
Note: if using 4 jacks and keeping car level you can skip this step since car will be level already.
5. Raise car and install drain plug and tighten 25Nm or 18 ft./lbs (if you don't have a torque wrench) tighten plug until you it is snug and add 1/4 turn (best estimate) Using a different drive will alter torque value (3/8 drive vs. 1/2 drive ex.) Torque =FxD, length of wrench will alter torque value.
6. Filling oil, open one bottle of Diff fluid and place pump on the bottle, place fill tube in the fill port and place drip pan under fill port, start pumping the oil into the differential. (if space permits I lower car slightly just to ensure the angle of car is close to its natural stance.) Keep pumping fluid until oil starts coming out of fill port.
IMG_0693 by da94450, on Flickr
IMG_0692 by da94450, on Flickr
7. Install Fill plug and torque to same specs as drain plug. wipe area clean and inspect.
IMG_0689 by da94450, on Flickr
8. Lower car (safely)
ZHP and X5 IROTS by da94450, on Flickr
9. Have another beer, you're done take her for a spin and one more inspection upon return (check for leaks)