Potential Explorer Build

[Wes B.]

Hey, guys! I have an '04 Explorer that I have had since new, and I'd really like to build it up. My goals behind this build are to create an Explorer that drives like new, is far more capable than when it came from the factory, and is still highway friendly. I know this platform isn't the easiest to work with, but I hope you guys can critique my build plan and help me modify it if necessary.

Engine: I am planning on doing away with the tired, anemic SOHC 4.0l V6 and replacing it with a more modern, efficient Duratec 37 from a 2011+ F-150 or Mustang. My biggest question with this swap: is it possible to make all of the electrical stuff work with this engine and it's respective ECU?

Transmission: The 5R55E is not the friendliest of transmissions, and I am thinking about replacing it with a manual: NV3500 from an S10 ZR2.

Transfer-case: The OEM transfer-case will almost certainly not bolt up to the NV3500 (I could be wrong, so does anyone know for sure?), and I am planning on swapping in an NP231.

Tires: Like I said previously, I would like this build to be capable off the road and still remain friendly on the road. Therefore, I would like to slap on a set of 245/70R17 Hercules Terra Trac's. I am open to other tire suggestions though.

Front and Rear Differentials: We all know that the front (27-spline Dana 30) and rear (31-spline Ford 8.8) differentials probably aren't the most suited for off-road use, but I really don't want to do away with them. My plan is to keep the 3.55 ring and pinion gears, do a full rebuild on each, and install Powertrax Lock-Right Lockers in each. Is there any other way to make these stronger or more capable?

Suspension: I'm not big into huge amounts of lift, but I do want to make the Explorer look a little more mean. I was thinking of installing a 1"-2" body lift (any specific kits out there?) and replacing the OEM shocks with more meaty ones (Fox Racing Shox, Bilstein, Rancho, etc. -- any suggestions on which ones to use?). Also, with all of these additions, would I need to replace the springs?

This is mostly a work in progress, and I want to nail down a solid plan before blindly attempting anything. I know plenty of people here have successfully modified their Explorers, and I am kindly asking for a little insight. Also, if you have any other ideas for possible engine/transmission/transfer-case combinations, then I'm all ears. Thanks!

 

[JoshMcMadMac]

Have you ever tackled something like this before? That is countless hours of fabrication and parts gathering. Best of luck!

 

[Wes B.]

Have you ever tackled something like this before? That is countless hours of fabrication and parts gathering. Best of luck!

I've done various SFA swaps, engine swaps, and transmission/t-case swaps but nothing to this extent. Trust me, I know there are tons of hurdles that need to be jumped through to make this entire combination work, but I think the end result would be worth it.

 

[Flingueur]

Here's a link to a 1.5" body lift for under $50

http://www.explorerforum.com/forums/showthread.php?t=312012

 

[Wes B.]

Here's a link to a 1.5" body lift for under $50

http://www.explorerforum.com/forums/showthread.php?t=312012

Perfect! Thanks!

 

[Wes B.]

Update: The other drivetrain option that I am considering is a Ford 4.9l I6 mated to an M5OD-R2 transmission and NP208 transfercase.

Does anyone know if this would be any easier of a swap compared to my original idea?

 

[Ronin8002]

Why not go for a 3v 4.6 V8 swap with the 6r60 transmission? That way you could use the existing transfer case, and it might not be such a nightmare to install and wire.

 

[Wes B.]

Why not go for a 3v 4.6 V8 swap with the 6r60 transmission? That way you could use the existing transfer case, and it might not be such a nightmare to install and wire.

The existing transfer-case will bolt up to a 6R60? I didn't know that. Although, I'd rather go with a 3.5l or 3.7l V6 instead of the 4.6l V8.

 

[HiImBrian]

Although, I'd rather go with a 3.5l or 3.7l V6 instead of the 4.6l V8.

Why? Parts are more widely available for the modular 4.6 than either of those, and for an efficient off-road rig there will be times where you'll want the extra power. If you're concerned with gas prices and mileage then a lift and aggressive tires would hurt you WAY more...

 

[Wes B.]

Why? Parts are more widely available for the modular 4.6 than either of those, and for an efficient off-road rig there will be times where you'll want the extra power. If you're concerned with gas prices and mileage then a lift and aggressive tires would hurt you WAY more...

The power gains that the 4.6 would provide would be minimal when compared to the 3.7. Yes, I know that a 4.6 costs like half as much as a 3.7, but the 3.7 offers the perfect amount of power while still remaining to be very fuel efficient.

The lift isn't going to be huge (1"-2") and the tires that I plan on slapping on the OEM wheels really aren't that aggressive nor are they that much bigger than the stock sized tires.

 

[HiImBrian]

The power gains that the 4.6 would provide would be minimal when compared to the 3.7. Yes, I know that a 4.6 costs like half as much as a 3.7, but the 3.7 offers the perfect amount of power while still remaining to be very fuel efficient.

I don't know where you heard that... Sure the 2v leaves a lot to be desired however the 3v & 4v can produce loads on power with simple bolt-ons and a solid tune. Never mind what you could get out of a 5.4...

And with just a body lift and stock tires, you're about as capable off road as from the factory. Keeping the 3.55's doesn't help either.

For the kind of money you're talking about putting into this thing, it would be less expensive and more efficient to buy a fuel-efficient vehicle and keep your Explorer (or something else) as a dedicated off-road rig. Just my 2¢.

 

[Wes B.]

I don't know where you heard that... Sure the 2v leaves a lot to be desired however the 3v & 4v can produce loads on power with simple bolt-ons and a solid tune. Never mind what you could get out of a 5.4...

Aaaahhhh...I didn't factor into account aftermarket modifications.

 

[HiImBrian]

Aaaahhhh...I didn't factor into account aftermarket modifications.

Sorry, with everything else you want to try and do I just figured the entire build would be aftermarket. With the lower price of the 4.6 and the added power it already has over the 3.7, the money saved could easily be spent on aftermarket parts for both for the engine and suspension. But I'm just trying to think efficiently.

 

[Ronin8002]

Aaaahhhh...I didn't factor into account aftermarket modifications.

Agree with Brian here...work smarter not harder. If you feel the 4.0 is anemic, why not look into regearing the diffs to 4.10, or adding a supercharger. Either one will make a huge difference in the way the truck accelerates, and can help with fuel economy also when using larger tires. You could get both mods done for about 3k I would think. I suspect a 3.7 ecoboost swap would run triple that, if not more, when all is said and done.

The existing diffs seem to hold up fine for offroading. Weak point is probably the axles themselves but I never had an issue in my last truck (a 2004) with 32s and a rear locker. Don't bother with a lunchbox locker in the front of these trucks unless it is a selectable...that is, if you need a front locker at all (i didn't feel like it was needed in my last truck).

 

[Wes B.]

Sorry, with everything else you want to try and do I just figured the entire build would be aftermarket. With the lower price of the 4.6 and the added power it already has over the 3.7, the money saved could easily be spent on aftermarket parts for both for the engine and suspension. But I'm just trying to think efficiently.

I am realizing that, and thanks for the suggestion. Also, wiring won't be as much of a pain since the Explorers did come with a 4.6 as an engine option. How much power is the 3-valve 4.6 capable of with a few bolt-ons and a tune?

 

[Wes B.]

Agree with Brian here...work smarter not harder. If you feel the 4.0 is anemic, why not look into regearing the diffs to 4.10, or adding a supercharger. Either one will make a huge difference in the way the truck accelerates, and can help with fuel economy also when using larger tires. You could get both mods done for about 3k I would think. I suspect a 3.7 ecoboost swap would run triple that, if not more, when all is said and done.

The existing diffs seem to hold up fine for offroading. Weak point is probably the axles themselves but I never had an issue in my last truck (a 2004) with 32s and a rear locker. Don't bother with a lunchbox locker in the front of these trucks unless it is a selectable...that is, if you need a front locker at all (i didn't feel like it was needed in my last truck).

The gearing depends almost solely on the transmission being used. I'd keep the 3.55 with an NV3500 just because 1st gear is plenty low and the OD is slightly better than the one in the 5R55E. If I decide to go with a 6R60/80, then I'll probably regear the front and rear to 3.73 or 3.90.

I figured the weak point would be the axles. Do you know of any company that manufactures stronger aftermarket CV axles?

 

[Ronin8002]

The gearing depends almost solely on the transmission being used. I'd keep the 3.55 with an NV3500 just because 1st gear is plenty low and the OD is slightly better than the one in the 5R55E. If I decide to go with a 6R60/80, then I'll probably regear the front and rear to 3.73 or 3.90.

I figured the weak point would be the axles. Do you know of any company that manufactures stronger aftermarket CV axles?

True. If you went with the 3v 4.6 and the 6r60 you would be well served with 3.55 or 3.73...the first two gears are so low in that transmission that I hardly noticed a difference when I went to larger tires on my truck. You might have some luck going and finding some factory geared 3.73 diffs from the salvage yard and using those to save some money. But you could always just run it with the 3.55 at first and see how you like it, then decide.

There are companies that could make aftermarket CV axles but if it were my truck I would worry about putting my money towards the engine/transmission swap first. FWIW, I have only heard about 1 instance of a snapped CV axle with these trucks and it was on a sport trac adrenaline running the mustang 5.0 coyote motor, and even then, it happened at the track when he was hopping the wheels....so I would think you'd be fine with a mildly modified 4.6.

As for suspension, the only off the shelf, bolt in upgrades are the rancho quicklift assemblies. They come already assembled with application specific springs, so you could just throw away your stock strut assemblies or keep them as backups. The benefit of the quicklifts (besides the mild lift) are adjustable valving for fine tuning the ride characteristics. Also, the front struts have more travel than the OEM or OEM replacement types so they are a pretty good upgrade. You could also run aftermarket coilovers in the front like rangermidtn or I have done. But in the rear there isn't a whole lot of extra travel to be gained (the OEM type struts already travel nearly 6", any more than that and your axles will hit the edges of the frame hoops), so the only advantage to running aftermarket coilovers in the rear would be improved ride quality (basically what you would get from the rancho quicklifts).

 

[Wes B.]

Update: I found an Ecoboost 35/ 6R80 transmission/ Borg Warner 4419 transfer-case for $6,500 at a salvage yard near where I live. The entire set came from a 2011 F-150 with only 33k miles on the odometer. My questions: Is this a good price for this set? What potential hurdles would I need to jump through to make this work over a Modular 4.6/5.0/5.4 or a Windsor 302 swap?

 

[Wes B.]

Update: Outside of sourcing the engine/transmission/transfer-case necessary for this type of build (still not sure what combination I want to go with: pros and cons with each?), I've been tossing around the idea of swapping both solid front and rear axles. The reason being they are far simpler, can handle more power, and are easier to lift when compared to the independent suspension system. Any insight?

 

[HiImBrian]

Update: Outside of sourcing the engine/transmission/transfer-case necessary for this type of build (still not sure what combination I want to go with: pros and cons with each?), I've been tossing around the idea of swapping both solid front and rear axles. The reason being they are far simpler, can handle more power, and are easier to lift when compared to the independent suspension system. Any insight?

For the 11 years the 3rd gen has been out, I only know of 1 SAS'ed 3rd gen and the guy isn't even on here. One of the other guys on here found it for sale and took some pictures of it. The consensus here was the guy did it, but not very well.

1 swap in 11 years? Just forget about it man.