New Gen 1 Owner

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.



Dec 8, 2022
Reaction score
All fluids age, regardless of use, and become increasingly acidic with time. So front and rear differentials, transfer case, transmission and filter, and power steering fluid. You might also consider a complete gravity bleed of the brake system, too.
- Transfer case; 50 ounces of Mercon LV
- Rear Differential: 75W-140
- Front Differential: 80W-90
- Transmission: Mercon LV
- Brake System: DOT3 (The system will gravity bleed just fine. It just takes time, patience, decent music, a couple beers, and some aquarium tubing.)
- Power Steering System: Mercon LV. Pull the reservoir's bottom hose with a catch can under it. It's simple. If you do this every other oil change you will never need to replace the PS pump.

You will find - if the previous owner did not make modifications - that neither differential has a drain. You can use a suction device and get as much as 95% of the old fluid out, or you can remove the differential covers. Be advised that Ford does not merely seal the covers, they bloody glue them down. Removal of the rear cover is challenging, and exceptionally challenging in the case of the front cover. because physical access is so limited. The transfer case DOES have a drain. Amazing.

The transmission deserves a thread of its own and there are several here. Suffice it to say that Ford opted to use a "diptoothpick" that is so close to the exhaust system that thousands of mechanics all over America must have burn scars on the backs of their hands. The fill procedure is a two-step method, with the final level made when the transmission is at full operating temperature. And that's where the burns come in. A glove with 4 or 5 layers of duct tape across the knuckles will help. You will probably still get burned, but not as severely and you'll heal faster. Read up on the two-step fill procedure and crawl under the truck and familiarize yourself with what it'll take to do this successfully before you decide to do it yourself. Lots of us do, but I promise it fails the fun test.

Check the air filter and replace as needed.
Check the cooling system, drain and replace coolant if it's dark in color: Motorcraft Orange prediluted, PN VC-3DIL-B.

Changing the spark plugs can also be challenging. A good selection of extensions, wobble extensions, a u-joint, and a real good quality spark plug boot tool is necessary. The combination of extensions is different for each plug, so some good 3D problem solving is the order of the day. The top 8 are easy as long as the coils are okay. The bottom 8 plugs must be accessed through the wheel wells. The front right plug is right in line with the shock tower and is the most difficult to get to.
Thanks for the detailed write up Ruger

All seems easy enough aside from the transmission fluid, servicing autos make me nervous. May be a stealership service if they're willing to touch it with the mileage it has.

Great advice on the power steering fluid, my plan to make it last was to not go full lock and full throttle at the same time.

The rear diff cover has definitely been off at some point. Does anyone make good covers with drain plugs? Toyota diffs are just to easy, my old truck got fresh gear oil every 3rd oil change. Maybe excessive but most of my desert driving is done with the rear locked in 2wd high speed sliding, occasional air time. Truck is used 70/30 on road off road.

Truck also has airraid hot air intake, sounds pretty sweet. Will find a pre filter sock to go around the dry filter. Would throw a stock airbox back in if one came up.

Very familiar with the gravity bleed although these days the beers are subbed out with la Croix.


FRF Addict
May 16, 2011
Reaction score
Northern Nevada
@DMDRaptor , I can give a first-hand endorsement to Mag Hytec's rear differential cover. I put one on my 2011 SuperCab in 2014, and I can attest to its quality and ease of use. PN Ford 12-9.75. See here:

aFe also makes differential covers, but I bought their transmission pan and the mounting holes didn't line up very well. I tried and tried to get them to respond to communication and so did the firm that sold me the pan, but aFe never responded to either of us. The retail firm that sold me the pan expressed astonishment at that. "Let the buyer beware."

I also have the Airaid intake. I bought the pre-filter sock directly from them. Ask them for more of the rubber gasket that goes around the top edge of their airbox extension so that you get less hot air from under the hood. Hint on the factory airbox: The intake through the inner fender is full of protrusions and obstructions to smooth airflow. I took mine out and rounded and smoothed the protrusions. Once you get it in your hands and examine it, I think you will agree that some Dremel work followed by fine wet/dry sandpaper polishing makes good sense.
Last edited: