Engine, differentials, and maybe tranny swap question - Diesel Forum

Tricks87 · 11-03-2009, 06:49 PM

I have a 1992 F-150 with a 5.0 gasser and e40d tranny. Im looking at a 1991 f250 thats a "parts" truck, i want to take the 7.3 idi engine and drop it in the 92 along with the front and rear diff, but the tranny is a manual so i don't know if i really want to do all that work of mounting a clutch pedal and pokin a hole in the floor for the shifter. How big of a swap is this? im a mechanic myself so i have the tools and all. But im just curious what im in for. the truck i have now is coil spring in the front and the other truck is leaf spring.

Thanks guys

rsr911 · 11-03-2009, 08:51 PM

I'd do a frame swap. More than likely you'll need the ECM (TECA) for a 92 diesel for the trans to work properly. There will be wiring issues etc. but things like clutch pedal and hole for the shifter should be easy. There should be a removable panel where the shifter goes and you should be able to swap the pedal assy from one truck to the other. This is assuming they are both the same bodystyle, I know the vans changed from 91 to 92 but I don't know about the trucks. Doing the frame swap will give you the heavier frame and should be easier than trying to swap engine, trans, axles, etc. Basically unhook and unbolt the bodies and swap from one to the other as well as the beds then you'll just have the chassis and body wiring to figure out.

I'm in the middle of a swapping the frame and interior from a 99 Explorer V8 to a 96 Explorer V6, there are a lot of minor wiring changes between those to years so I elected to swap all the harnesses as well.

Tricks87 · 11-03-2009, 11:03 PM

thanks for the advice, and yes they body style changed from 91 to 92 but i think the doin the frame swap though may be the better way to go, how are the 5 speeds for these trucks i thought they had clutch problems but wasn't sure. Also where can i find that ecm? if i decide to use the auto tranny?

rsr911 · 11-03-2009, 11:29 PM

Well that makes it a little more difficult. Your 91 diesel with manual trans had no ECM (actually it's the TECA for transmission electronic control assembly, or PCM for powertrain control module). You likely have the digital odometer in the 92 correct? If so it should get it's signal from the rear abs sensor and send it to the PSOM (programmable speedometer odometer module) attached to the rear of the speedo. If you stuck with the manual the swap would be easier as you would have an all mechanical motor and trans yet the speedo would run off the original electronics, you'd just have to splice in the chassis harness to the cab harness with the ABS wires. You could likely use the engine harness for the other stuff like fuel shut off solenoid, cold advance and cold idle as well as figure something out for the glowplugs. My guess is with a copy of both truck diagrams in hand and some time with the harnesses and you could get it to work easily. If you wanted to go with the E4OD you would need one from behind a diesel as your's will not bolt up. You'll also need the associated sensors like the FIPL on the injection pump, tach sensor, and barometric sensor and tie this into a diesel TECA, probably more work than it's worth. As far as I know the only issue with the diesel 5spd is the dual mass flywheel but there's a conversion kit for a single mass flywheel. I'd stay with the manual box if it were me as it would be loads easier. I'd take a look at the body and bed mounts, my bet is they line up but check to be sure. You'll need the pedal assembly from a manual 92 truck as I doubt the 91 will bolt in. You'll also need the floor plate with the shifter boot. It would be a cool truck in the end though, F150 badging with a heavy duty diesel driveline and axles.

Tricks87 · 11-04-2009, 08:27 PM

well sure sounds like you know your stuff lol, i like the idea of the frame swap would probly save a heck of alot of time, but the 91 is a extended cab long box i believe and the 92 is a regular cab long box, would i be able to cut the frame down? or is this just alot of work in general?

rsr911 · 11-04-2009, 08:52 PM

Quote:

Originally Posted by Tricks87

well sure sounds like you know your stuff lol, i like the idea of the frame swap would probly save a heck of alot of time, but the 91 is a extended cab long box i believe and the 92 is a regular cab long box, would i be able to cut the frame down? or is this just alot of work in general?

Cutting and sectioning a frame is not something I'd recommend to anyone who isn't an experienced welder. Why is the 91 a parts truck? bad title? major damage? What about just fixing it up and selling the 92? Even better if the body and bed are bad on the 91 find an extended cab 150-350 and swap that body and bed onto the 91, less headache and you can still sell your 92 to offset the cost.

To give you an idea on what can be done with time, creativity and a little money: my Porsche was originally a 1966 912 4cyl car. It now has been converted to a 911 with a 1983L 3.0 6cyl. I used carbs from a 2.2L 6cyl and put in larger venturis and jets. I used a 71 911 trans because it fit best. It has tie rod ends from a turbo, front and rear suspension from a 90's 911 Carrera, flairs from a early 80's SC and a 1974 IROC body kit. "S" brakes front and rear. It weighs 1850 empty, makes 200rwhp and goes like stink. I collected everything on ebay, enthusiast forums and swap meets.

If you have a car to drive during the process this could be a really fun project.

Tricks87 · 11-04-2009, 09:03 PM

yeah i thought about fixing it up, the guy wants 325 for it, it needs quite a bit of lovin, its missing the radiator and maybe some other little things, but its got potential, i'd really like to throw a solid front axle under it. Also like to turbo it, nothing really needs to be done to do that right? just bolt everything on right? here i'll PM you the craigslist.