Just got done changing the fluid in my front differential. It came out an opaque, milky grey/green. Hard to say how many miles were on the fluid, as I've only had the truck a year and about 1500 miles.

P.O. had the rear end redone before I bought it. I figured he'd have changed the front and xfer case fluids, too. No joy. Xfer case looked OK, just brownish red, but the front diff? Green? What the heck????

Andy

 

Same here! 2000 4.6. I bought the truck with 89K and changed all fluids before the 100k mark. The stuff that drained out of my front diff was the same ugly color. I'm willing to bet that it was original and had 100,000 miles on it.

Must be something about that lube that it looks that way when it gets too old!

 

Follow-Up:

I dumped my pan this morning, and took a closer look at the fluid. It was still translucent, almost clear, on my fingers, and still felt very slick. Not watered down, either. Maybe someone put a friction-modifier in the fluid turning it this funky color?

Andy