alright fellas, i have a technical question that i need no bull **** answers for. i need to swap a 5.4 from a 98 expedition with automatic tranny with push button 4wd into a 97 f150 with a 4.2 5 speed and 4wd on the floor. i understand i need the ECI and wiring harness out of the expedition, but i want to keep it manual tranny and keep the 4wd thats already there. i can i buy a bell housing kit for the tranny to go from the 6 cylinder to the big 8? will the 4wd in it now work with the the new computer that was set up for push button 4wd??? any help would be much appreciated

 

I don't know about a bell housing kit. the 5.4 will not bolt up to 4.2L tranny as is. the pcm would work but you would have to have the automatic shift point shut off via SCT. The engine mounts would have to be modified as well. the manual 4wd would work just fine with the pcm with electric 4x4 switch.

 

Find an MDOD-R2 from a 4.6 truck. That transmission will bolt up to the Navi motor. The Navi engine should have an 8 bolt crankshaft but count the bolts just to be sure. A flywheel from a 4.6 truck engine will be needed. Depending on the bolt pattern from the Navi engine you will need either a 6 or 8 bolt flywheel.
Your 4.2 PCM will not run the 5.4 engine so you will need a either a Navi PCM and have the transmission function turned off. A 4.6 PCM from a manual truck and have it adapted to run the Navi engine or a 5.4 PCM and have it adapted to run the Navi engine and have its transmission functions turned off. The simplest solution would be the Navi PCM. Your 4.2 exhaust will not bolt up to the Navi engine exhaust manifolds. Your truck is a 97 and you are using a 98 Navi engine so you should not need to worry about the PATS system. You should find the wiring schematics from both the PCM you use and your truck to be sure that the PCM will properly communicate with the transmission, instrument cluster and GEM.

Long term if you drive it hard the transmission will not last nor will the 8.8 differential.

 

i was told by a dealership that the 4.2 and 4.6 use the same manual gear box. but your saying its not. will the 4.6 tranny and flywheel bolt right in or will i need a different drive shaft? you also said that this combo wont last in the long run, why is this? should i use the rear end out of the expedition also?
how do i disable the tranny function on the computer? thanks so much for all your information.

 

OK,

The 4.2 and 4.6 both use a M5OD-2 manual transmission but with different bellhousings.. Because the transmission has an integral bellhousing the transmissions are different and will not cross over. I have broken 5 transmissions. Three of them were with a 4.6. I have also replaced three 8.8 differentials. I now have a 9.75. I am on my second transfer case. Your Navi engine is more powerful than a stock 4.6 so don't expect things to last if you push it. Why didn't Ford offer the M5OD behind a 5.4? Because it would not last. The Expi doesn't use leaf springs. Find an F-150 with a 5.4 engine, the diff should be a 9.75. If you use a manual M5OD tranny and your existing transfer case You would be able to reuse your existing drive shafts.

Regards

Jean Marc Chartier

 

i see. its a one piece transmission, i was led to believe it was a gear box with a seperate bolt on bell housing. i cant thank you enough for taking the time to answer what must seem like dumb questions with some worthy information instead of more conflicting crap that i have been getting. i have only done direct swaps in these late model vehicles, never anything of this magnitude and just want to be as prepared for what is instore as i can be.
having said that, you have raised another question... actually two questions. first off, what rear end is in the expedition? an 8.8 or 9.75, the reason i ask is because, although your right about the suspension, i have converted my 97 eddie bauer to leaf springs and shocks with a kit. while they work great the down side is that the front spring shackles hang down real low and hang up and drag when offroading, this can be some what remedied with taller tires and might be worth the trade off if it is the stiffer diff in the expedition. the second question is this: does ford make a stiffer manual tranny to mate with the 5.4l ( or an aftermarket tranny that will easliy bolt up)? if so why not go with that gear box instead of from a 4.6 like u suggest? please educate my ignorance so i dont have as many headaches in the long run. i want to go about this the right way.

 

Can't help you much. But they do offer a 6-speed manual with the 5.4 F250. Not sure if it will work on an F150 though.

 

There are three 4x4 capable transmissions. By that I mean ones that have the correct bellhousing bolt pattern and are adapted to bolt a transfer case on the other end. The three that are available are obviously offered on Fords. The M5OD-R2 that I mentioned, and two ZF transmissions. The 5 and 6 speeds offered on the SuperDuty. I cannot at this time say for sure that the ZF transmissions will fit in the f-150. I do know for sure that they will bolt up to the 5.4 engine as they already do so in the SuperDuty. I know that the NPG transfer case offered with the SuperDuty will also bolt up. That much is obvious. About 6 or 7 years ago I researched installing a ZF in my truck. I had sourced the measurements and came to the conclusion that the transmission would interfere with the transmission tunnel. I cannot find this research. Too many computer crashes and I lost the information. I now have a 3 inch body lift so that is no longer a factor. I can state with no fear of being wrong that a ZF transmission will fit with a body lift. I am in possession of a NPG transfer case and I will be taking measurements to see if it will fit on the M5OD transmission. Spline count and depth of inputshaft are of great importance. I know that the gasket that fits between the transmission and transfer case is the same so I am confident that it will line up. But the other two factors may negate the hole process. I will be able to tell this summer when the weather turns warmer and I am able to get outside and manhandle the t-cases. I wish I had a garage. My plan is to install a ZF 6 speed in my truck. If I use the NPG transfer case I will need a SuperDuty yoke as the NPG transfer case does not use a slip yoke. That will involve custom drive shafts. If I can use the BW 4406 transfer case on my F-150 I will have greatly reduced the cost of the swap.

You could always find a T-56 transmission like the ones used in the Mustang cobras. They are in effect a gear box with detachable bell housings. The unfortunate thing is that the extension housing houses the shift mechanism. You would either have to fabricate an extension housing with the proper adapter surface to mount a transfer case or divorce the transfer case. A divorced transfer case would require the fabrication of a crossmember to mount the transfer case along with a custom shortened drive shaft. I suspect that at the very least 1 foot of space between the two would be required to allow room for the universal joints and telescoping shaft to be able to install and remove the shaft for service. Divorcing the transfer case will require shortening the driveshaft by the amount you spread the transfer case away from the transmission. This will increase the driveshaft angle and add stress to the slip yoke and bushing. The shorter the wheelbase the greater the angle. One more thing about the T-56 transmission is the available gear ratios. There is no low gear.

Some Navigators with the 4.6 may have had the 8.8 differential. With a 5.4 you will run the risk of failure because of the torque. Specially off road where you may encounter situations where you are applying torque to wheels that are stuck fast. Ford never offered the 8.8 with the 5.4.

Regards

Jean Marc Chartier

 

again, i thank you for the info, at this time i think ill just go with the m5od like you originally recommended and see how long i can get it to last, but i am definetly interested in seeing how your transfer case project works out so keep us posted. i have been all over these ford and truck forums for a week straight and while everyone acts like master mechanics, none seem to know what they are talking about. thanks again JMC you can use my garage anytime.