This question is asked about once a week. Here's the latest/greatest answer:
15w-40 is the oil you should use year round where you live. If you lived where it really gets cold in the winter you would want to switch to a lighter weight fluid, at least in Winter.
As for coolant, you truck should have come with the new, at the time, Gold coolant, not green. It looks more brown than gold though. Also just to clear this up, if you are running traditional green coolant, you don't have to use a coolant filter, this isn't what a filter is for. The proper way to monitor SCA levels in the coolant is to test it every 6 months and add the proper additive as it is needed. The pre charged filters are useless, you may be over loading the system with sca additives. It doesn't test the coolant so it knows just how much to release, wouldn't that be cool, lol!!!! Instead it is like one of the blue things that you use to stick in the toilet to keep it clean. It slowly breaks down as the water flows over it. That is where pre-charged filters belong, in the commode.
Now running a coolant filter is a good thing to do. The reason for this is because the cast blocks are constantly leaching sand from the casting process. This sand doesn't play well with water pumps and you can guess who wins. Use a non charged filter to remove the sand from the coolant system and this will prolong the life of your water pump. I couldn't believe how much sand came out of mine and the truck only had 21K on it when I added the filter. This is also a good time to switch the upper rad hose to one that is used on a dual alternator set up, this will route the hose around the fan belt and not through it, another brilliant Ford idea!! If you are changing the coolant it is a good time to switch to a true ELC coolant like the Fleetrite, and you don't have to worry about checking SCA's for 300K and out to 600K if you use the extender at 300K. I myself will never leave any fluid in the truck that long, but it is good that I could.
One of the most neglected fluids is brake fluid. Brake fluid attracts water/moisture. Ever notice when you bleed to brakes the first fluid that comes out is jet black, that is the water in the system. I change mine every 2 years, if I tow heavy I will do it more often. Last time I flushed I used the Super Blue brake fluid and I have been very happy with it. It doesn't attract water, and it has a higher boiling point, this means it can stay in longer, but I will still flush it at the 3 to 4 year mark.
Speaking of brakes, Ford used the cheapest rotors they could on these trucks. Turning them will help until you heat the rotor up again. You can't turn a hard spot out of a rotor. I replaced mine in 2005 with Powerslot/Hawks cyro'd rotors and Hawks LTS pads and couldn't be happier. I also changed the front brake lines to SS which helped firm the pedal up. If you know Fancy Gap mountain on hwy 77, I came down that mountain towing a friends 20K trailer and 1/4 of the way down lost trailer brakes, a true butt puckering moment!!!!! The brake upgrades proved themselves to me, I sure wouldn't of wanted to come down that mountain with that load with a stock brake system.
Replace trans every 30-35K, or 20-25K if you tow a lot. Only use Mercon III fluid, if you have a stock trans, if your trans has been rebuilt in the last few years it is okay to use Mercon V. Please, nobody reply with "Mercon V" is now approved for the 4R100". I have proved it many times on this forum. Your owners manual says NOT TO USE MERCON V in the 4R100. Then all of a sudden in 2007 Ford came out and announced that Mercon V was now approved. But they never said why, what changed. I went as far to contact the refineries that make this fluid and asked if it had been reformulated in any way the way so many claimed. False, no change was ever made. Mercon V won't kill the trans in 20 miles, more like 20-30K, it takes time to destroy the materials in the trans. Ford knew darn well that by the time it caused any issues they would be long out of warranty and they stood a chance of selling the owner a new trans. If you think Ford wouldn't do that you are mistaken. They did the same thing when they switched to the gold coolant in 2005 (IIRC) they claimed it was maintenance Free free for 100K, that was until some of us started to test it. Right out of the jug is failed miserably at meeting min levels of sca. But do you have any idea how much money they saved by using one fluid for all their cars and trucks? It was multiple millions of dollars.
Transfer case, use a good synthetic fluid, which is ATF. Mercon V can be used in the Transfer case with no issues.
Flush power steering fluid with a quality synthetic ATF fluid and it will help in cold weather and turning when truck is just at a idle.
Ball Joints don't last on the 7.3 because of the weight of the motor and Ford didn't use serviceable ball joints. Replace when needed with nothing but Moog Ball Joints with zerk fittings and you won't have to worry about ball joints for a long time.
Calipers should be taken apart and the slide pins lubed properly with the correct grease, otherwise you will end up with a frozen caliper pins and a strong pull to one side.
If it were me I would change all radiator and heater hose lines, as well as a new fan belt as it is a good number to remember ( call it 100K ). I keep a log book of what I did and when so I can tell when something needs to be done.
I highly recommend sending a oil sample to Blackstone Labs. You wouldn't believe how much information you can gain from a scan of your oil. I send in every third oil change. They can alert you of a possible problem long before it becomes a failure.
I didn't get into any serious mods, because you didn't ask about that. But another item I recommend is a full set of gauges, trans, pyro, and boost. Even if you keep her stock, these gauges can be a huge help in diagnosing issues you might have. I always recommend these first so you can get a good baseline feel for how the truck performs, so that way you can actually see how different mods really affect your powertrain or really don't. Lot's of internet hype out there!!!!
Most important thing to tell you is to buy a spare cps (cam position sensor) and carry it with you and the tools to change it on the side of the road. 10mm socket, short extension, ratchet, and a flat blade screwdriver. When the cps goes it is like someone shut the key off and you will be dead in the water. I changed mine out in the middle of a thunderstorm in 10 min with a state trooper standing by telling me the whole time that if I didn't have it moved in 5 min he was going to call a wrecker. I think he was shocked that I actually knew what I was doing, lol!!!! When I bought my truck they were $160, now they are under $30 at the dealer, so get one or two and the tools to change it.
If you have any questions on how to do any of the above just send me a PM and I will help you all I can.
Think too about creating a signature (see below at mine for a reference).
Congrats on your new truck
Pro Comp 6.5" Lift
Pro Comp 16x10 Alloys
35x12.5 Nitto Mud Grapplers
Sky Jacker Hydro 7000 Steering Stabilizers
K&N CAI JUNKED
For A 6637
Straight Piped Dual 4"
Jasper 4R100 (Rebuilt in '05)
Dieselsite Coolant/Trans Filters
ISSPRO EV2 (Boost, EGT, Trans)
'07 Headlight Conversion
Monitoring with Torque