Changing Differential Oil

[Learning]

How difficult is it to change differential oil on E30 M42?
A mechanic told me he would charge $85 to do it, but this includes the oil. The labor is $45. Does this price sound about right?

Also, what grade of differential oil do I need and how much?

[AndrewBird]

Seems reasonable, but it is very easy to do, so why not do it yourself?

If you do, make sure you remove the fill plug before you drain the oil. If you can't get the fill plug out and already drained the diff, you are screwed.

[Learning]

I don't have a lifter to lift up my car. Or can I use car racks/ramps?

Does Jiffy Lube or Good Year tire shops perform differential oil change?

[matthugie]

Jacks or ramps are fine. The only things you need are a 10mm allen head wrench or socket and a pump to put in the new fluid. You can do it in 10-15 minutes pretty easily.

[AndrewBird]

Yes, a floor jack and jack stands is all you need. DO NOT climb under the car unless it is supported by jack stands. Drive up ramps will also work, as long as your car has enough clearance.

[Learning]

My mechanic told me I would need a gallon of differential oil. Is this right? He says I need to change the gear oil also.
Is the gear oil the same as differential oil?

[Dj Buttchug]

My mechanic told me I would need a gallon of differential oil. Is this right? He says I need to change the gear oil also.
Is the gear oil the same as differential oil?

lol your mechanic is wrong. small case diffs hold about 1.5 qts

[roguetoaster]

How difficult is it to change differential oil on E30 M42?
A mechanic told me he would charge $85 to do it, but this includes the oil. The labor is $45. Does this price sound about right?

Also, what grade of differential oil do I need and how much?

$75 is more fair considering the crap oil they may put in there.

I have used 75w-90 gear/diff oil for quite some time now in my DD. 1.3 qts seems to be closer to what I end up using for a diff change.

Be aware that you need a near to level surface to refill the oil "correctly." Overfilling won't hurt it, but it will dump that extra oil out of the overflow/breather. As to draining, lift the rear, support on stands, break the fill plug loose, then the drain plug. To drain it more or less completely either use a suction device or lower the car back down when the plug is off and elevate the front of the car.

[brads2002]

Also make sure you have a fluid pump or hose and funnel with a 90 degree elbow at the end. You can't tip the bottle enough to pour it in there. If you have a limited slip make sure you use diff oil that is for a limited slip. redline is good stuff.

[Nick_S]

It takes around 30min total to do. Even with the most basic knowledge you can do it. All it takes is unscrewing two plugs and putting fluid back in.

I used Mobile1 75w-90 with LS additive.