just changed rear diff fluid

[Rhett]

I put AMSOIL 75W-90 synthetic gear lube in there today, and some pointers if you're thinking about it:

1) I had to pull the diff cover to drain the old fluid. I did buy a suction gun, but it had too wide and stiff of a tube to reach down into the tiny fill hole--I couldn't use the suction gun to remove the old fluid.

2) The Haynes manual didn't mention a gasket, it said to just use RTV silicone. I went ahead and used a gasket + silicone, and cross-tightened the bolts.

3) I sanded and painted the diff cover (black, of course! No street queen green for me) while I was at it.

4) Once the cover was off, I cleaned up the gears with alcohol and solvent. They looked good at 102,000 miles; no scuffing, etc. And there was no apparent big pieces of crap in the old diff fluid either. But it was time to change it.

5) if you do this, you will spill some diff fluid, it's a messy job.

6) don't over-torque the diff cover bolts (they are 1/2" bolts). Torque to about 35 ft/lbs.

7) refilled the diff using the suction gun thru the fill hole.
Put in approx 2.65 quarts, which is the spec amount
for the 8.8" rear diff on a 94 Explorer. For some reason the Haynes said 95+ Ex's rear diffs hold a little more.

8) took about 4 hours but that includes watching football and messing around a lot.

I hope I get a little more mpg out of it.

 

[Hartman]

Thanks for those tips, I will benefit from them when I change my fluid in a few weeks. Where did you get your gasket from?

 

[huskyfan23]

Did it have to be changed or you just wanted to switch to synthetic? At how many miles should it be changed?

 

[Rhett]

I used a Felpro gasket, I got it at AutoZone for about 4 bucks,..personally I like OEM Ford gaskets better though.
It's a $4 piece of cardboard with bolt holes in it...

With dino gear lube, generally after 100,000 miles it wouldn't hurt to crack a diff and change the fluid--unless it's synth fluid (as with V8 Explorers) in which case Ford says it's "lifetime". Even with synth I would change it after that time, but that's just me. I did it to change to synth--and it was raining and cool today so...

If you frequently get the rear end in water, fairly deep water from creek crossings and the like, then it is always a good idea to change it then.

BTW, the rear diff fill plug is strange...it is a square fitting requiring a 3/8" socket extension to open it...it's located on the front of the rear diff facing the front of the truck. Difficult to get to because of the fuel tank and driveshaft, but it can be done.

 

[Hartman]

Also, how much fluid is neccessary to fill it back up?

 

[88vert]

Do you have a suspension lift?

 

[Chew_12]

Also, how much fluid is neccessary to fill it back up?

Put in approx 2.65 quarts, which is the spec amount

 

[DeRocha]

I fill the diffs until the fluid reached the fill hole.

 

[LOGJOCKY]

If I dont have a suction gun where can I get one and how much$$? Also is there any other way to do it without a suction gun. I can empty it ok but getting the fluid back in will be a b*tch

 

[Opera House]

Refilling is the worst part of the job

Did my 97 a couple months back. Just used a thin silicone film on the cover with no leaks so far. Old fluid was nasty at 130K and there was metal on the magnet but the gears looked fine. Didn't have a pump. Used a long tube attached to the bottle inverted like a funnel with the bottom cut out. Tied it with string to the rack. This is a SLOW process but cheap.

 

[DeRocha]

I can empty it ok but getting the fluid back in will be a b*tch

Get some clear tubing at the hardware store. Connect it to the gear oil bottle and squeze it in..

 

[LOGJOCKY]

Never thought of that..thanks!

 

[LOGJOCKY]

One more thing, how do I get the fluid out of my front diff???

 

[DeRocha]

You can remove the fluid with a hand pump, or make one youself. I made one and it works like the suction thing at a dentist office.

 

[LOGJOCKY]

How would I go about making one of those hand pumps?

 

[Rhett]

Originally posted by DEROCHA
I fill the diffs until the fluid reached the fill hole.

Which works out to be 2.65 quarts on the 8.8 rear diff.

 

[Rhett]

A suction gun is only $10 and it worked fine for refilling.
I spilled a little but to me it seems like it would be a real b*tch trying to fit a bottle of lube with a tube on it in there, unless you've got a body lift...

 

[stubborn1]

One thing I did to help fill the rear diff on my 98 was to remove the sensor on top. There was one screw to remove and the entire unit pulled out.

I then added new fluid until it ran out of the fill hole. The top hole seemed much easier to access than trying to fill thru the regular hole.

 

[Rhett]

One thing I have noticed is that my ABS light has not come on since I changed the rear diff fluid. Previously I cleaned the ABS rear sensor, but still got the light. Now, after changing the fluid, it hasn't come on yet...
I wonder what this means?

 

[Hartman]

There's probably a problem with the censor, it just happned to occur after you changed the fluid.