Differential Lubricant?

[Big Z]

I have a 2001 explorer sport 4wd. My repair manual says to use 80W/90 for standard axles and 75w/140 for traction-loc axles. How do I know which axle type I have?

 

[rileyrs]

look at the tag on your door and find out your axle code.
then compare it to this:
http://www.therangerstation.com/tech_library/Axles.html

 

[Big Z]

Thanks. It's a D4 (Limited Slip). I'm guessing I use the same in the front?

 

[my pos mounty]

same gear ratio, yes. Limited slip? no

 

[Big Z]

Okay, so ~75w/140 in the rear and ~80w/90 in the front?

 

[my pos mounty]

I believe that the rear calls for a synthetic 75W/140 manufactured by Motorcraft and also to add the friction modifier. You could run the same fluid in the front without adding the modifier, or any synthetic 75W/90. No modifiers are necessary since the front is not an LSD and does not have the clutches a LSD does.

 

[Big Z]

Thanks for the help...never done a diff. lube change.

 

[my pos mounty]

Thanks for the help...never done a diff. lube change.

You may want to get some sort of suction device to suck the diff fluid out of the front differential thru the fill hole. Unless you want to drop your entire front axle carrier. You can not remove the cover because of a crossmember, and there is no drain.

 

[rileyrs]

i used a little $4 siphon pump for my front diff.

 

[Big Z]

I hardly ever use 4wd--is it worth it to change the oil in the front diff?

 

[my pos mounty]

Yep, even if you do not use it, it still turns as you drive down the road, although not under any drivetrain pressure.

 

[jrowe6]

there's no reason i cant use some 75/90 in the rear of mine right, i have an open 3.73.

 

[rhauf]

after recommendation by a driveline shop, i use the thick stuff (80w140, or whatever) in everything.. it dissipates heat better and lubricates better at higher temperatures.

 

[Elessar65]

If you live where it gets really cold I would go with a lighter weight oil, at least in the winter time. I use full syn 75/90 in my front and rear, now that I don't have that silly limited grip anymore.

 

[barenfang]

Gear Lube

I am planning on changing the gear lube in my 2000 Explorer 4wd. I have a 3.73 open diff and would like to use Royal Purple 75w/90. I am wondering how many quarts do I need to do both front and rear differentials?