1996 XLT Rear Diff - Best Fluid

[nitro71]

Mix away.. You can mix motor oils at will. Can't see that gear lube is any different.

 

[SCB2525]

If the differential cover listed by Advance Auto comes with a gasket (which it seems to looking at the picture of the same exact part on Rock Auto), I think I'm gonna get one. It's only $19 and the gasket is $5 anyway. I'll hit it with a couple coats of black high-temp.

If I do that, I might as well go all the way and get new bolts too (I've inspected mine, they're not in good shape). Does anyone know what size they are?

I know I keep coming back to this with new questions and I don't mean to pester but I just want to prepare as much as possible and do this right and once (that is until the fluid needs changing via mileage).

 

[SCB2525]

So I changed the fluid with the aforementioned Redline/M-1 mix, used a gasket without RTV and slapped the old cover on after cleaning it inside and out (it wasn't that bad after all when cleaned). Then I painted the cover with some high-heat textured Rustoleum. The old fluid wasn't as bad as I thought it would be; someone must have changed it at some point. It was still definitely at the point of needing changing, it just wasn't "oh my god this is so deteriorated its sad" bad. I didn't know old gear oil stank so much.

No leaks in the last few days I've checked so everything worked out. A new tank of gas will tell whether I gained any fuel economy as a result.

Thanks a lot all!

 

[techieman33]

So I changed the fluid with the aforementioned Redline/M-1 mix, used a gasket without RTV and slapped the old cover on after cleaning it inside and out (it wasn't that bad after all when cleaned). Then I painted the cover with some high-heat textured Rustoleum. The old fluid wasn't as bad as I thought it would be; someone must have changed it at some point. It was still definitely at the point of needing changing, it just wasn't "oh my god this is so deteriorated its sad" bad. I didn't know old gear oil stank so much.

No leaks in the last few days I've checked so everything worked out. A new tank of gas will tell whether I gained any fuel economy as a result.

Thanks a lot all!

My amsoil was nasty after maybe 10k miles, we're pretty sure it's from tearing up the L/S clutches, now how would that happen:scratch:





























Oh wait I know:smoke:

 

[SCB2525]

According to the last 2 fillups, I've gained a solid 2-3 MPG.

 

[Chrisman889]

Where would I locate these codes? I have a 93 Explorer 4x4 and just replaced my differential fluid with Coastal 80w90, will this be ok? or do I need synthetic 75w140 as recommended by the Haynes manual?

 

[RobertFord]

The 1st gen manual says 75w90 for an open and 75w140 for a limited slip differential. You can find the axle code on your door sticker.

I'm curious to hear if it would be beneficial to use 75w140 on an open differential, anyone?