afg

so my truck is 7 years old and i have never changed the fluids except for transmission when it was rebuilt under a year ago

so i need to change power steering, coolant/radiator, brake, diff and a couple more.

so my question is what kind of fluid should i replace it with? should i just go to autozone and get some from there or should i get something from ford.

thanks for any advice

firehose777

Rear diff is " lifetime fluid " so you shouldn't need to change it unless you are really hard on it. Brake and power steering is a definite. I use premium fluids but everyone is gonna have a different budget and recommendation. I don't buy stealership fluids simply because you can get pretty good stuff at your local parts store quite a bit cheaper. I'm a Valvoline and Royal Purple guy, but that's just my preference. If you do end up changing the rear diff fluid, you have to use a vacuum evacuator or better yet, pop the diff cover off to drain it. Our rear ends don't have a drain plug. Don't forget that its a full synthetic fluid with a friction modifier in or added to it. You can buy it with or without it already in it. I've run Valvoline fluids in every vehicle I've owned since I was 16 and had really good luck with it. Good luck with your project.

afg

thanks. i guess ill go with autozone becauuse im on a tight budjet.

also the reason i wanna change the diff fluid is because i drive almost always on pavement and do some reckless things once in a while so i rather be on the safeside. ill take it to my mechanic and ask him to do the diff fluid change.

thanks again for ur input

firehose777

Doing the rear diff is actually really easy...now I don't know your mechanical ability, but It's just a matter of takin the bolts off the cover, lettin the fluid drain out, and puttin the cover back on. You can buy a gasket for it, but some high temp RTV from Autowrong or O'Reilly Auto works just as good or better. Then refill it with the full synthetic gear oil which is I believe 75w140 if I'm not mistaken. Don't forget it takes either buying the oil with the friction modifier additive in it, or adding it yourself. It's really not a difficult task if you have a drain pan and basic hand tools. I did mine in the drive way in about 30min.

Tradesman

You will need friction modifier for the rear differential only if you have a limited slip differential. Stuff smells like death from what I heard. Front differential doesn't require friction modifier as it's an open differential. The transfer case has a drain and refill plug. Do these procedures after you've driven for a while to make the fluid hot and easier to evacuate. Just out you don't burn yourself.

Use a Motive brake bleeder and replace with a higher temperature rated brake fluid but with the same DOT.

Coolant should be compatible with Motorcraft.

rmilam

FYI, I had my local shop change my rear diff fluid and they used Amsoil with friction modifier already added to the gear lube. Total waste of money as I had to replace it and add the ford friction modifier as the rear end would vibrate and groan every time I made a turn. The friction ford friction modifier was about 7 dollars for the bottle and once I changed it out, the groaning and vibration went away in about 2 miles of normal driving with turns. Supposedly ford gears are very finicky as of what type of friction modifier the clutch packs like. HTH

RON

techrep

iTrader: (1)

Where does it state that the Front and rear Diff's are lifetime ???

bobkyle2

It don't list a time to change the fluid. Unless its a Dana Axle. I just looked(Unless i missed it)...

I thought it said every 100k, But i can't find anything stating that. I change mine every 25k,

I just don't know

The diff fluid is a lifetime because its full synthetic that being said. You should change it if the axle is ever submerged in water. Or usually around 100 k I believe the clutch packs needs to be serviced on the t lock if you have one so at that point you would Change the fluid.

Tradesman

I don't believe in any lifetime non-service recommendation. Although it comes straight from the manufacturer, I find it hard to believe. All fluids break down. I wish I took pics of my rear differential fluid when I had my rear pinion seal and axle seals replaced. At 180,000km it was as dark as Wesley Snipes. Considering how much work I put my truck through, I don't imagine Ford would tell me it is okay to leave the fluid forever. I work my truck as if it's an F-350!