Vapiano

I decided to swap out the differential fluid this afternoon while doing an oil change. I was very surprised to find the differential oil was still in excellent condition after 66k original miles. There was no difference in color between the old and new fluids.

Anyone else have this same experience?

BimmerFan52

I changed at 82K miles.
Saw a difference in color but the oil fluid didn't look terrible.
I didn't expect it to look too bad as it is a sealed system. Primary effect on the fluid is heat.

Vapiano

My old fluid looked like the sample on the left, the original owner was a stay at home mom; I seriously doubt the car was ever driven hard or in inclement weather. I am amazed at how clean the undercarriage still looks.

ETNav382

I'm at 101k and did mine last weekend. I replaced it with redline fluid and the old fluid was slightly darker than the new. I've had the car for 3.5 years and put on about 60k miles,

I've heard that the redline doesn't hold up as good as the OEM stuff, so I'll be doing another change at about 130k and see how it looks.

Margal

I noticed that Diff fluid won't change much in color as engine and trans do, but there might microscopic particals presented from metals. I changing mine every year because it is not that expensive and hard to do. Going to use a magmatic plug next time I open it.

atl530i

I changed my oem fluid yesterday @ 101k in a 2007 530i. Bought @ 80k. My fluid was very burnt and dark in color. I filled with redline 75w-90 and I have noticed my clunk from P -> D lessened. It was in dire need of changing. 30k from now on. Easy job to keep the car tip top.

paran

Best thing to do when changing diff fluids is to add a magnetic drain plug.

Cheap and they are very effective at removing metal contaminants which dominate the materials composition of the differential.

Vapiano

Definitely doing this next time around!

turboawd

mine had about 90k and looked like new fluid.