Fordfan2006

So I'm going to be changing the front and rear differential fluids in my 1995 F150 4x4 I've already picked up a bottle of Ford friction modifier ( limited slip ) how much fluid does the 8.8 take and the front axle? Also the transfer case ( floor shift if that matters ) and what fluid weights do they take? ( I know to get transfer case fluid for the transfer case )

Phil48315

On the 98 8.8 rear diff cover there is a tab that says 75/140 syn.......check on yours
The local auto parts store confirmed this also...call them with your info
the owners manual might give some info also...
you can google it .... Good luck

BLDTruth

80w90 for the rear plus the additive
75w90 for the front
Dex/Merc ATF for the transfer case

Fordfan2006

Synthetic? They don't make any or sell it at advance anyway.. for the rear.

BLDTruth

I think that all 75w90 is synthetic - 80w90 can be either. TBH when I did my front end I just used the 80w90 I had leftover. For as often as I use 4WD it won't make a difference. And unless you are towing/hauling heavy loads, I would just get cheap stuff. I don't subscribe to the logic that people use to justify spending $20 a quart on royal purple for their differential. It's oil.

Fordfan2006

Well I'd be using 4x4 often and I plan on towing quite often with it ( riding mower and push mower on a utility trailer )

Martian

Oil is oil (so long as it's accredited). Royal Purple is marketing hype. End'o'story.

Fordfan2006

So I changed it and found this in the bottom of the differential. What is this? All the gears looked great and the spring wasn't broken or anything for the clutches.

David Young

Looks like a belt buckle for a Leprechaun .

Just a guess, sometimes during assembly of certain parts, they might have knockout protectors that are to keep dirt out of the part. For faster assembly of the truck, they just leave it in the differential. Like I said just a guess

Fordfan2006

Thanks haha I just took it out and left it out.