7.3 Maintenance

[Mack450]

I have had my PS for a little while and I was wondering what kinda maintenance does this require? I changed the oil on it immediately when I got it as well as the fuel filter. How often does the fuel filter need to be replaced and how long for the oil? Is there anything else I should be doing for regular maintenance?

[MKeeney]

How often you change the oil depends on what type of oil you put in in the first place. If it was regular car oil you need to change it right now. Diesel oil is different than gasoline engine oil. Synthetic oil will go farther than dino oil. Quality diesel synthetic oil such as Amsoil, Lucas or Royal Purple will go even further. How far you go is directly relative to how much you spent on the front end, except when it comes to Royal Purple. RP costs a lot more and doesn't get you any farther down the road than Amsoil or the others in that group. Beyond that you should change your oil at the recommended intervals listed on the oil itself and adjust for the type of load you put on it. Heavy towing=more frequent oil changes, etc.

Tranny oil is every 30k miles.

I do the fuel filter every other oil change.

I also put an additive in the fuel tank every time I fill up. I use Lucas Injector cleaner but there are a lot of others on the market. All are better than nothing.

[usnavyad]

ok my truck im and very ocd
I always run diesel clean grey then white then grey again lmao
rotella 15w-40 every 5k with motorcraft filter due to our heui injection system oil is critical
fuel filter every other oil change
havent done trans service yet bout to though

[rufushusky]

Originally Posted by Mack450

I have had my PS for a little while and I was wondering what kinda maintenance does this require? I changed the oil on it immediately when I got it as well as the fuel filter. How often does the fuel filter need to be replaced and how long for the oil? Is there anything else I should be doing for regular maintenance?

Per the OEM, the fuel filter needs to be replaced every 15k and don't cheap out on fuel filters. Motorcraft, Donaldson, Baldwin and Fleetguard all make good fuel filters for the 7.3, water separation is key on a diesel and not all filters are created equal.

If you have an auto, you need to flush it every 30k.

With respect to the oil, the factory recommends 3000-5000 miles OCIs depending on operating conditions. International recommends 8-10k OCIs on the same engine. So there is some wiggle room IMHO. 5-7.5k seems reasonable to me and it is what I shoot for. If you live in a location where it gets cooler to cold, under 20*F, then a diesel (CJ or CI rated oil) 10w-30 or 5w-40 will help cold starts.

[rufushusky]

One other thing to consider is coolant. If you keep the green flush it every 15-30k...keep/go gold every 5 years or 75-150k or ELC change it every 6-8 years.

[Skew12]

Some great info here.

[JEL]

All great info so far. I'd also like to add, don't forget about the differentials, transfer case (if 4x4), brake fluid, and even power steering fluid. You should flush your brakes with a good dot 3/4 synthetic every 2 years at most, I like to flush my power steering with Mobil 1 synthetic ATF every couple of years as well becuase if you lose a pump you can lose your brakes (ask me how I know).

Here's my routine:

Oil: every 3-4k with Rotella or Delo and a Motorcraft or Donaldson oil filter

Fuel: Every 10k wtih a Motorcraft, I also run grey Diesel Kleen every so often

Air: I keep a close eye on my AIS, change as necessary

Diffs: Rear Mobil 1 synthetic 75w-140 and Front: synthetic 75w-90 every 40k

Transfer case: Ford XL-12 "Transfer Case FLuid" every 25k or so

Brakes: Castrol or Valvoline synthetic dot 3/4 every year or two-at most. I plan on doin ATE Super Blue next time around

Coolant: E99 so no ELC, but I use Fleet Charge and flush yearly (check SCA levels each oil change)

Power Steering: Every two years or so with some synthetic ATF

Manual Trans: Every 40k with synthetic, when I do my diffs

Grease: I grease with some marine grease every oil change, ever other at the latest

[ttyR2]

The info I have said that Dexron/Dexron 5 ATF is used in the transfer case, but I've seen one or two comments about the Ford XL-12 fluid instead. The Ford owners manual says to use ATF. So....which is it? (I just changed mine out and used Mobile synthetic ATF)

Do you run the friction modifier with that Mobile 1 synthetic gear oil in the rear end, or do you not have the limit-slip diff?

[rufushusky]

Originally Posted by ttyR2

The info I have said that Dexron/Dexron 5 ATF is used in the transfer case, but I've seen one or two comments about the Ford XL-12 fluid instead. The Ford owners manual says to use ATF. So....which is it? (I just changed mine out and used Mobile synthetic ATF)

Do you run the friction modifier with that Mobile 1 synthetic gear oil in the rear end, or do you not have the limit-slip diff?

XL-12 is a lower friction modified ATF (similar to Dex/Merc), Mobil 1 synthetic ATF will work JUST fine.

Most people who have used high end gear oils like mobil one don't need the friction modifier for it. Throw it in there, take it for a spin and see if you need it. If you do swing by Napa and buck some up while you are test driving. I didn't need to add any to my Red Line gear oil when I swapped out mine.

[JEL]

From what I understand of the XL-12 thing, Ford recommends not using a Mercon V in the transfer case, and XL-12 is just overpriced Mercon 1 that Ford originally designed the transfer case for. I'm not sure what the reasoning behind this is, it's a pretty simple system, but for some reason they don't want Mercon V in our older cases so I just buy the XL-12. AFAIK the Mobil 1 synthetic univeral ATF is ok to use, I use it in my ZF-6 and I remember reading on the label that it is certified for Mercon as well as the newer Mercon V.


As for the diffs. I do have limited slip but I've never needed to add any modifier with the Mobil 1, whcih is why I keep using their stuff, makes it a little easier and it comes out looking really good at 40k so it would seem to be good quality (albeit somewhat pricey).