Rear Differential Fluid Change- 1st Generation Explorer

[Techniker]

I am planning on replacing the rear differential fluid for a 1993 Ford Explorer 4WD. Since it is RWD most of the time, I am changing the fluid for my friend. To my horror she has informed me that it has never been changed (and the vehicle is at 185,000+ miles). I looked at the Haynes manual and it makes the procedure look simple. I have changed differential fluid before.

However, it appears where my fill plug is located is blocked by the fuel tank with the drive shaft blocking the middle of the differential. I can't even see the fill plug but it was getting dark. It is supposed to be on the driver's side of the differential and on the front facing the drive shaft. This is correct, yes?

Even when I do manage to find it, how on earth do I get at it? There isn't enough clearance in there to do anything and if it is stuck, good luck getting a breaker bar in there.

-Techniker

 

[tgreene92]

i have a 2nd gen but if i recall thats where it was on my friends 1st gen. it should just be a 3/8s ratchet that screws it off, use a 3/8s extension to get to it if you don't have enough clearance as well as putting it up on jack stands if you have to. and the plug shouldn't be on there that tight my rear fluid wasnt changed til 120k miles and it still came right off, hit it with some pb blaster if you have too i doubt a breaker bar should be needed.

 

[Techniker]

i have a 2nd gen but if i recall thats where it was on my friends 1st gen. it should just be a 3/8s ratchet that screws it off, use a 3/8s extension to get to it if you don't have enough clearance as well as putting it up on jack stands if you have to. and the plug shouldn't be on there that tight my rear fluid wasnt changed til 120k miles and it still came right off, hit it with some pb blaster if you have too i doubt a breaker bar should be needed.

Thanks for the response. Do you remember how the rear differential fluid looked at 120,000 miles?

-Techniker

 

[iLoveMyExploder]

I would like to know exactly what kind of fluid goes into the differential... I searched it on autozone website, and it took me to "gear oils".... if that's the right stuff, how much does it hold, and whats the proper weight to put in it? ....my ABS light comes on and I read somewhere that if the differential fluid is low, that could be a possible cause of it....

 

[RangerX]

Standard 80/90 gear oil for a 93, although you could go with a fancier newer 85/140 if you wanted.
Interesting about the abs light and low oil. Doesn't make sense, but I'm no expert. And my abs light has been coming on sporadically and I haven't checked my diff oil level in ages...

Do you know how to check for the proper level?

 

[Maniak]

However, it appears where my fill plug is located is blocked by the fuel tank with the drive shaft blocking the middle of the differential. I can't even see the fill plug but it was getting dark. It is supposed to be on the driver's side of the differential and on the front facing the drive shaft. This is correct, yes?

You are in the correct location.. as [MENTION=116628]tgreene92[/MENTION] said, it is a 3/8 square socket. You just put an extension into that to take it out...

One important tip.. Make sure you can get the fill plug out BEFORE you take the cover off.. You not only fill the diff with that hole but that is how you know when it's full.

When our X was more stock it was lower and yes, that is a tight fit in there but we could just get a 1/2 ratchet with an 1/2 to 3/8 adapter and an extension in there. Nowadays I just use a 3/8 drive impact wrench to take it out.. I've gotten lazy (or better tools) over the years.

As for fluid, Personally I run the Mobile 1, synthetic 75/140 stuff. When I last had the cover off I could see some wear on the face of the gears and those gears have been in there well over 200k miles with a locker..

~Mark

EDIT: WOW, I just noticed this is a really old thread.... To the more recent question, I stand by what gear oil I use... AS for the ABS light.. on a 1993 there are ABS sensors by the front wheels and a single on in the rear diff. I've cleaned off the sensor on the rear diff's ABS sensor (easy to take out the top) which helped it. Since then I have fixed my ABS by pulling the fuse, and the bulb but I did that because the ABS wasn't happy with a Detroit locker in the rear and it didn't help on loose dirt.. so I just killed the ABS.