Warning for front differential oil level after oil change!!
 

Warning for those who have changed their front differential oil and have filled it up to the neck of filler hole.If you are filling up to the neck then you are over filling it.It takes exactly 600 Ml.

I just did mine today at 95000 kms and found that only around 550~600 came out. But when i filled it,it took around 800~850 ml up to the neck of the filler hole.I didn't see any leak and was little confused.Then i checked in ISTA and it clearly stated that correct amount is 600Ml.Then i had to drain around 200 ml.Its not that dangerous but better to keep in the spec.

My rear differential oil had a very little change in color and front differential oil was little darker than rear.Transfer case oil was quite dark.Then i performed the oil change adaptation reset in ISTA.

Thanks for that! I changed my front diff last year and put a Motul synthetic 75W90. Of course I filled it up to the filler hole. I was a bit frustrated to find out that a 35k miles diff has a leak from the driver side axle seal. Now i know the problem is probably not there, but I will have to find a way to measure the quantity left inside.

Agree...

Not to mention filling to the plug level was in original BMW repair manual

Is there any replacement interval? I can see replacing the transmission filter and fluid it gets dirty with the band's wearing. Wouldn't the transfer case just have gears?

Automatic transmissions, as our ZF's, are operated and lubricated by a specialized hydraulic fluid. Automatic transmissions have largely advanced beyond shifting bands, using sprag clutches in their stead.

The xDrive transfer case does not have a differential between front and rear drive, but a servo operated multiplate wet clutch. Perhaps all xDrive differentials between left and right wheels have servo operated multiplate wet clutches between the differential and the side, i.e. two per 'axle'. That allows the computers to minutely vary the power to each wheel (power being the product of torque and angle rate).

Lubricants wear and so do their additive packages become exhausted. A good model for a lubricant molecule is a molecule-sized roller-bearing. The atomic bonds within the long chain molecule fatigue and break.

Beyond that, lubrication is a specialized technology. In a luxury car, why quibble over the cost of a fluid replacement?

Is this for the diesel only? Or is it for all x5? What about the rear differential, does it only take 600ml of fluid also? Thanks, Sam

Bump

Rear differential takes upto the filler neck.not sure about if it's same for all E70's or not?