My diff fluid is a dark brown color. It looks nasty and im sure its not supose to be like that. Any help is appreciated. Thanks

 

Yep, dark brown is about right for used gear oil. You should be ok, how many miles do you have on the truck?

 

with your truck being on '01, you should go ahead and change it....but to answer your question, gear oil is susposed to be dark brown and stink....

 

if its white that means water got in it. but ya, it smells pretty bad

 

Cool. Thanks for the help. It has 77,000 miles on it. I feel alot better knowing its ok. I will be changing it in the near future. I have to make a 3 hour trip tomorrow and just wanted to be sure. thank again for the help.

 

you should change it as soon as possible....it isn't critical, but 77,000 miles is a bit for diff fluid...

 

yeah i'll probably do it tonight just to be safe

 

Geez, I change mine every 30,000 miles

 

um yeah id say

 

my front has come out like, olive drab a few times...

 

has your tcase every been drained....mine has never been changed until last week at 72k....and all I can say...is YUCK.

 

I have 120k on my 98's stock fluid and it seems fine?

I can understand preventative maintnance But I dont think ford recomends that you change it to much i mean yeah 100k its time for some new fluid I dont know how many miles you think you should change it?

 

You are worried about a 3 hour trip? Ha...come to Texas where a 3 hour trip isn't bad. Make an 8-9 hour drive to the south part of Texas, and then we'll talk of being concerned.

No grinding, whining, metal/bit chunks, or watery dark dark brown oil? Your fine. Diffy 90 weight oil is pretty stout...