Parts and tools:
- Mighty Vac oil extractor (or any plunger/syringe ect to draw out the fluid)
- 14mm hex socket
- Various clear flexible vinyl hose (to extract)
- 2L of 75w-90 GL-5 spec (i used Liqui Moly 75W-90)
- Oil drain pan
- Floor jack
- Torque Wrench
- New rubber O-ring for the plug
1. Make sure your car is level ground, place an oil drain pan below the diff, then get your 14mm hex bit and remove the fill plug, replace the rubber-O-ring on it.
2. Insert your oil extract hose into the fill port hole of the differential there is no drain plug on the E70’s so your going to have to use some sort of oil extractor or syringe.Pro-Tip: to extract the most oil out of your diff, use the floor jack and lift the front of the car this will allow all the fluid to pool at the back of the diff, and use an 90* Angle bend or a U shaped hose for easier extraction.
3. Start pumping the mighty vac or extract the fluid you should get ~1L out.
4. Fill the Differential till its begin to streams or leaks out of the hole it took about 1L + ~100ml. This particular brand (Liqui Moly) has a build in spout for easy fill i just stick it in there and fill it up.
You can bend the pipe and it will still fill up just fine with no leaks!
Tilt it up so you can get the most out of the bottle.
5. Then replace the cap and torque it down to 44 lb/ft torque or 60nm, as per BMW tightening bolt spec sheet. The AutoZone’s hex socket was a tooth too long for the click torque wrench to fit but it eventually with some fussing with it.
No changes in driveability, the fluid that came out was Golden honey brown, not bad assuming that was in there for 5 years and 68k miles. No metal shavings (had a NEO Denyum magnet around the mighty vac oil extraction line) observed.