4.0 to 5.0...Problems?

Ford_Nova · January 25, 2009

Im going to attempt to switch my 97 XLT from a 4.0 to a 5.0 and was wondering if there would be any problems.

Ive got my old 97 Eddie that i have as a doner vehicle. The 5.0 is an AWD truck while the 4.0 is just 2WD. Ive talked to a few people asking about what it would take and if there would be any problems. Was told that the 4.0 tranny wont bolt up to the 5.0...and the 5.0 would be missing the tailshaft that i would be since it has a TC.

Had people tell me that itll drop right in, just need to take the computer out of the 5.0 and keep it with the motor. Some say that it wont, and cheesy said something about the rear end gears?

section525 · January 25, 2009

If you have the complete donor there then you're golden. But you will have to convert the whole thing to awd. Unless you want to find a 2wd transmission.

But having two '97s will make this project as smooth as possible.

What's cheesy?

Ford_Nova · January 25, 2009

So i cant use the one from the 4.0? or the tailshaft from the 4.0 to use on the 5.0?

and cheesy is "CHEESYPOOFS"

Mbrooks420 · January 25, 2009

The 4.0 trans won't work (you wouldn't want it anyways its a real POS) You'll need a 2wd 4r70w, or swap in the complete front axle, and the AWD trans and t case.

Cobraguy · January 25, 2009

No...you can't. Totally different drivetrains. If you are staying 2WD, then you will need to disassemble the 4WD trans and install a 2WD output shaft, speedo drive gear, etc. You will need to buy a tail housing and maybe a mount. I'm not sure about the cross member. It may work, or you may need to find a 2WD crossmember for a 5.0. And of course, you will need to buy a 2WD driveline...although it's possible the existing 2WD driveline will work with the proper slip yoke. Check for proper length.

Since the donor is a 4WD, I am trying to think if the PCM will have any problems going in a 2WD vehicle. I can't think of any right now. Worst case scenario is you would need a 2WD PCM anyway, and those are cheap enough. But I'm betting the one you have will work without problems.

BBQ Bandit · January 25, 2009

Depending on your state inspection/emissions requirements... can't change engine size in PA... Shops will refuse to inspect with different engines specifications (different engine block). Saw a few people turned away with a different motor then originally speced out.

CHEESYPOOFS · January 25, 2009

if im not mistaken since he has all the stuff from the awd he can just convert it all to awd taking the 5.0 the awd 4r70w the t case front and rear driveshafts and the rear end and just bolt em up correct? oh and 1 more question will he have to use the rear end from the 5.0 or can he use the one from the 4.0 2wd? and how do you find your gear ratio is there any way besides checking your differential cover? If the 4.0 gears are less than 3.73 wouldnt it just be smart to use the 5.0s rear end?

Mbrooks420 · January 25, 2009

He would also have to swap in the front diff, spindles, axle shafts and all of the other related things that are 2wd/4wd specific. You can check the gear ratio by looking at the door tag. The V8 will be a 3.73, I assume, I think they all are. D4 is the code for a 3.73 limited slip.

CHEESYPOOFS · January 25, 2009

yea the 5.0 is all 3.73 but the 4.0 came with a few different gear ratios

Mbrooks420 · January 25, 2009

BBQ Bandit said:
Depending on your state inspection/emissions requirements... can't change engine size in PA... Shops will refuse to inspect with different engines specifications (different engine block). Saw a few people turned away with a different motor then originally speced out.

I'm assuming TN has very relaxed inspection laws. Even so I could easily get a non factory motored vehicle inspected in PA with zero problems. And since it would technically look 100% stock, i wouldn't worry to much.

wyochimneysweep · January 25, 2009

why not leave the awd case on the trans and just not worry about hooking up a front driveshaft. if he has the complete donor i would think he could use the rear driveshaft off the donor. I would do this in a heartbeat if i had donor vechilce. get both of them to north dakota and i'll cut you a great deal on doing it. I'd even make your 2wd into awd if you wanted to go that way

Mbrooks420 · January 25, 2009

It would be less efficient since it would be trying to send power to a front diff that isn't there.

eXcali · January 25, 2009

Mbrooks420 said:
It would be less efficient since it would be trying to send power to a front diff that isn't there.

Does the 97 awd run on the traction management system. I know thats not the name but can't think of it. So it would detect your front wheels spinning and could cause some issues. Also the AWD uses 75% front 25% power rear, I think those are accurate numbers. So in theory it wouldn't work, I know it adjusts power to the wheels that grip, but I thought the max was 50/50 so you'd be losing 50% of your power.

wyochimneysweep · January 25, 2009

you dont lose anypower it doesn't slip it will send all the power to the rear wheels. the viscous clutch inside the transfer case locks up when axle speeds are different between the rear and front. but its not like your engine is going to have 25 percent faster to keep the same speed. and the parking not holding with the front shaft out is b.s. I've ran mine all summer with out it and parked on hills with a 5500 lb trailer hooked up overnight and it never creeped down the hill. your going to get alot of different opionions from here so good luck in your quest. It will be easy to do just time and money. but with a donor it should be more time then money

eXcali · January 25, 2009

wyochimneysweep said:
you dont lose anypower it doesn't slip it will send all the power to the rear wheels. the viscous clutch inside the transfer case locks up when axle speeds are different between the rear and front. but its not like your engine is going to have 25 percent faster to keep the same speed. and the parking not holding with the front shaft out is b.s. I've ran mine all summer with out it and parked on hills with a 5500 lb trailer hooked up overnight and it never creeped down the hill. your going to get alot of different opionions from here so good luck in your quest. It will be easy to do just time and money. but with a donor it should be more time then money

I thought the max an AWD clutch inside the transfer case would do is 50/50? Provided there would be no load on the front 50%, but you'd still be losing some power and effeciency (mpg) even if there isn't a front axle hooked up. I haven't tried it myself, just trying to wrap my mind around the idea of it and playing a little devil's advocate.

wyochimneysweep · January 25, 2009

with my front shaft out didn't lose any mileage at all just wsted rubber if you punched the gas and going sideways. lol

wyochimneysweep · January 25, 2009

people also say it will wreck the transfer which i cant see possible and have drove it during the summer the last three years with out the shaft installed and in the winter with the shaft installed.

Ford_Nova · January 25, 2009

well i dont really want to have to swap the whole front end off of the 5.0...not sure it will even work as my right tire is cambered out like only NASCAR should be. Id really like to have it 2wd unless i can get a selectable 4wd tc.

And emissions shouldn't be a problem. Im from IL where there are no emissions, so i should be good there.

Im going to try to get started on this tomorrow...depends on what Curtis says. Was told he should let me, but im not sure.

CDW6212R · January 25, 2009

You don't have to touch the GEM module, the AWD trucks have the identical GEM as a 2WD. To make it 2WD you would be best to find an output shaft and tail housing from a 2WD 4R70W. I'd avoid running the AWD without a shaft for 2WD, and those are expensive if you don't even want 4WD. You get some snow in Nashville, I'd keep the AWD if I had it.

Mbrooks420 · January 25, 2009

You can get a selectable bw 4406 from a Expedition F150. The AWD case is ALWAYS trying to send some power to the front. I'm not sold on it damaging the t case as I have driven several thousand miles without the front shaft., Oh and the truck will certainly creep without a front shaft.

4.0 to 5.0...Problems?

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