'99 passed down from the mom-in-law.

[ExplorerTom]

The A4WD seems to fail in the "always engaged" position. If you turn tight as you can on pavement and the driveline seems to bind up, then it is engaged. If you pull fuse 104 in the underhood fuse box and the binding goes away, then the Brown Wire Mod is an easy solution to the problem. It allows you to disable the a4wd function and drive around in RWD.

I too installed a switch to keep the a4wd but in all actuality, I never use it. It's RWD or in 4wd. If the roads are slippery enough to need extra traction, I'll engage the 4wd and leave it there. Or I'll keep it in RWD and have some fun.

 

[101Expedition]

So just pulling the fuse is not the answer, you actually have to cut the wire??
Also, what engine oil do you use?

 

[ExplorerTom]

If you pull the fuse, it does the same thing. Sorta. But if you pull the fuse, you've got RWD 100% of the time.

If you cut the wire, you still have the 4wd selections via the switch.

 

[404NltFound]

As for power, as 55moose stated, these are fat girls. Don't get me wrong, BBWs are fun, but can't expect them to outrun Usain Bolt. However...
Procharger. But, if you don't want to drop $5.5K on the truck, I'll tell you what I'm doing to start. My first truck was an extended cab, 02 Fx4. Still not a light vehicle by any stretch of the imagination. I put Flowmaster 44s in true dual on it, a K&N CAI, and a superchips tuner. The truck for its size and weight, was unnaturally quick. No Lightning obviously, but in high school racing the only trucks that were faster were single cab, 2wd trucks with built motors while mine was relatively stock.

So for now, my expedition in getting an aFe CAI with the dry filter, it has a Magnaflow exhaust, and I'll be getting a tuner from 5 Star Tuning with custom tunes. Some people will argue the effectiveness of a CAI but I put one on my 05 4 Runner and it really did seem to make it run better.

I'd change the spark plus too. I used to run iridium in my F150 but I was running 91 octane because "racecar". But with age and miles, horsepower does dip so anything you can do to help the motor breathe and that the fluids are fresh will help a lot. Mine is waiting to be picked up from the shop today as I just had all the fluids replaced. In your case i'd focus on oil, trans fluid, and coolant. Just my opinion.

Also, I don't know what gears you are running, and it's obviously not cheap, but going to 3:73s or 4:10s would make it feel more powerful, especially on the hills.

 

[101Expedition]

Okay... Rear end shudder was kinda noticeable at first. Now that i have about 4,000 smile miles on her, mostly to the Sierras and Nevada mountains (ish). She's been loaded down with all kinds of gear.
I did the brown wire mod and noticed an increase in mpg's and power i guess.
After several moderate technical trails over the past couple months, i'm noticing the rear end shudder is getting worse off the line while turning. Found out it's possibly the clutch pack for the limited slip. Wearing out or sticking together.
There are a lot of threads on here and i'm sure it's been covered but after searching for a bit with no luck, i'm just going to ask..
Any tips or tricks? Or just replace the pack?
Also, where does everybody get their parts from? Favorite online store?

 

[1955moose]

Why not try replacing the fluid with the Ford fluid and Ford friction modifier. If it don't work, your only out the price of fluids, and a half hour or so of your time.

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[Trainmaster]

That's what I'd do. The things are very partial to Ford fluid and modifier. It worked for me on a 2000.

 

[101Expedition]

Fluid it is then. Thanks. If it persists or comes back in a short time, i'll rebuild or replace.

 

[and0r]

listen to me carefully, you need to replace the throttle position sensor. its easy to do if you take off the trottle body, which is also easy.. but trust me on replacing that sensor. they are very weak and crumble internally due to heat and age. they also make up a large portion of how your transmissions brain works

 

[1955moose]

Wait a minute, your saying that a bad TPS sensor can cause a rear differential shudder? Like Jed Clampett used to say wee doggies! How, oh how can an acting up tps make the rear end go wonky? I guess anything's possible. We got Donald into 1600 Pennsylvania Ave, so I'm listening! Your turn.

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