School bus Cummins for my Ford

[wrenchtech]

I have recently acquired a 2000 model Ford F250 pick up truck. It has a V 10 gas engine. I think it would be a much better truck if it had a Cummins 5.9 diesel engine. There is nothing new about doing that swap, but I would also like to back it up with an Allison transmission. Some folks in the pick up truck world have been doing that swap. , But the expense that these folks are willing to endure is a nonstarter for me. I mean seriously, $10,000 for the engine part of the swap and another $10,000 for the transmission part.

The way it’s usually approached is to get an Allison transmission out of a GM pickup truck and then buy a bunch of expensive adapters to fit it up to the Cummins and the Ford transfer case. Along the way many guys are spending $5000 to get a high performance rebuild on the transmission (part of the 10,000 that I already mentioned).

I’m thinking I should be able to do the swap with parts from the medium duty truck world, including schoolbuses of course. In that world there are vehicles that come from the factory, like the Freightliner FS 65 School bus, with a Cummins 6B variant engine already mated to an Allison 2000 transmission , Which is almost identical to the transmission that GM uses in their pick up trucks

I am also thinking that I could do this for a fraction of the price. I have seen a number of used buses with the engine and transmission combination that I want for around $1000 . And of course I understand that I am going to have to find some solutions for engine accessory positioning and coolant hose adapters, and maybe replacing the exhaust manifold to reposition the turbo for better clearance, but that stuff is all chump change compared to taking the conventional route on the swap. I also will almost certainly have to spend some money on getting the transmission to run as a standalone in the new vehicle and for adapting it to my transfer case, But I still think that I can keep my budget way below what I’ve seen others spending.

By the way, it has become common wisdom to say that the Allison transmission needs an expensive rebuild before it can stand up to the low RPM torque of the Cummins Engine engine, but it may be the case that it is GM’s Allison transmission programming that is the problem. Apparently these transmissions do just fine in medium duty applications behind a Cummins engine because they are programmed by Allison and not by GM, who program their transmissions for smooth shifting with the Duramax engine which produces it’s peak torque farther up the RPM range. Some quite knowledgeable folks have lately been pointing out that all that is needed to make the stock Allison work behind the Cummins is to have the right programming in the transmission controller.

So I welcome any comments from folks who might have some worthwhile input.

[Truthseeker4449]

Do you follow Deboss Garage on YouTube? He's in the early process of swapping a Cat 3126 out of a bus (with some higher horsepower parts out of a bucket truck) into a F-350 and is using the transmission (though I'm pretty sure it's not the 2000) out of the bus. Still really early in the build, he just sent the engine out to be rebuilt.

I've wanted to do diesel swaps, but I just don't have the space for such work and now with the bus not the spare time and money.

[WIbluebird]

Lots of the school bus motors have larger intakes/manifolds/turbos that won't play nice in a crowded pickup engine bay.

Not only are you spending a small fortune on driveline adapters but you also have to buy all new turbos/other accessories just so it fits in there.

I don't think an Allison 2000 would fit in a pickup unless you raised the cab a bunch. Even then it might be too much weight. Never really thought about it so ymmv.

[EastCoastCB]

Originally Posted by WIbluebird

Lots of the school bus motors have larger intakes/manifolds/turbos that won't play nice in a crowded pickup engine bay.

Not only are you spending a small fortune on driveline adapters but you also have to buy all new turbos/other accessories just so it fits in there.

I don't think an Allison 2000 would fit in a pickup unless you raised the cab a bunch. Even then it might be too much weight. Never really thought about it so ymmv.

allison 1000's are in duramax pickups.

[Booyah45828]

Originally Posted by EastCoastCB

allison 1000's are in duramax pickups.

Not with the sae3 bellhousing, which I believe is larger then the duramax bellhousing.

Anything is possible. It all just depends on your level of fab skills and how deep your pockets are.

If it was me, I wouldn't do it, simply because most trucks around here that are 20 years old are rust buckets. Which makes the time put into a swap like this a waste because the truck will be scrapped in the next few years.

[WIbluebird]

Originally Posted by Booyah45828

Not with the sae3 bellhousing, which I believe is larger then the duramax bellhousing.

Anything is possible. It all just depends on your level of fab skills and how deep your pockets are.

If it was me, I wouldn't do it, simply because most trucks around here that are 20 years old are rust buckets. Which makes the time put into a swap like this a waste because the truck will be scrapped in the next few years.

If i spend that level of time and effort on a truck I'd get a rust free donor from down south or out west and then the entire rig would have to be parked in the winter after the swap was complete.

Pretty much the only way to keep stuff long term up here without spending thousands of dollars in bodywork every 3 years to keep it looking decent.

[wrenchtech]

Originally Posted by Truthseeker4449

Do you follow Deboss Garage on YouTube? He's in the early process of swapping a Cat 3126 out of a bus (with some higher horsepower parts out of a bucket truck) into a F-350 and is using the transmission (though I'm pretty sure it's not the 2000) out of the bus. Still really early in the build, he just sent the engine out to be rebuilt.

I've wanted to do diesel swaps, but I just don't have the space for such work and now with the bus not the spare time and money.

Yes I do follow the DeBoss Garage channel on YouTube. In fact I watched a couple episodes this last weekend. I don’t know how I missed the project that you are referring to, but I will soon fix that. Thanks for the tip.

[wrenchtech]

Originally Posted by WIbluebird

If i spend that level of time and effort on a truck I'd get a rust free donor from down south or out west and then the entire rig would have to be parked in the winter after the swap was complete.

Pretty much the only way to keep stuff long term up here without spending thousands of dollars in bodywork every 3 years to keep it looking decent.

I have already solved that problem.



I found this truck for sale just down the road from my house. It's from Montana and is, for all intents and purposes, rust free. When my neighbor saw the interior, he remarked that it looks like no one had ever sat in it. And it happens to have my favorite blue cloth interior that Ford offered at the time. It has a few hail dents, particularly on the hood, but no brand on the title. The price reflected that and it's something that I'll find easy to live with.

[wrenchtech]

So I have the truck, and with 164,000 miles on the odometer, the suspension is tight, it goes down the road straight, and the engine runs strong and smooth.

Now my mission is to figure out if I can do an ultra low budget swap using a Cummins engine and an Allison transmission from a medium duty application like a vocational truck or a school bus.

The reason I want to source for medium duty applications is that I can get a Cummins and Allison combination in one truck already working together, and I think I can get it for less money then try to find a dodge donor truck. Oh and I haven’t mentioned yet that I’m not looking for a 12 valve, mechanically injected, “P-pump” engine, I am specifically looking for a 2004 - 2005, common rail, electronically injected engine. Which is not to say that I couldn’t be convinced to use a later 5.9 engine or even a 6.7 if the right deal came around.

What I think I learned today, is that the medium duty Cummins engine is actually a better fit, electronically speaking, for pairing up with the Allison 1000/2000/2400 transmissions. Dodge never planned for their version of the Cummins to speak to the Allison transmission, but the medium duty Cummins applications have provisions in the wiring harness to send data to the Allison transmission control unit (TCU). Another tremendously important point is that there are transmission tuners that are experienced with tuning the whole range of the medium duty Allison transmission models.

As to the physical dimensions of the parts involved, there was some Internet chatter in the earliest days after the introduction of the Allison in the GM trucks, that it was too big to fit in the transmission tunnel of a Ford or a Dodge pick up. Or that the Allison 2000 had a bigger housing. I think that is all been pretty much disproved. The next thing for me to find out is if the SAE #3 bellhousing, that is used in the medium duty world to join the Cummins B6/B4 variant engines to the Allison transmissions, is the dealbreaker.

If this project starts looking like it’s going to be a black hole, I might just start looking for a G57 six speed manual transmission out of a 2007 - ? Dodge, a transmission that would meet my requirement of not forking out boatloads of cash for adapters.

[EastCoastCB]

PNW steve has a real nice Dodge diesel he was looking to sell. 5.9 with 6 speed manual. No swapping required.

[84chevyguyid]

One difference between the 1000 series and the 2000 series is the 2000 wont have a parking pawl setup in it as the vehicles those typically came in had air and or hydraulic brakes with their own parking brake system and didn't need the parking pawl.

[wrenchtech]

Originally Posted by 84chevyguyid

One difference between the 1000 series and the 2000 series is the 2000 wont have a parking pawl setup in it as the vehicles those typically came in had air and or hydraulic brakes with their own parking brake system and didn't need the parking pawl.

I was aware of that. And I can see where it could be a problem in states where you have regular safety inspections. Running an automatic without a parking pawl would be a good reason to keep your e-brake/parking brake in good working order. It’s also a good reason for me to investigate further to see if adding a parking pawl is possible. I have been in situations before where all four wheels, or at least wheels on both the front and rear axles were needed to hold a vehicle on an incline with low traction due to ice on the road.

Another thing that I’ve noticed is that the price of a used Allison 1000 transmission has come way down in the last few years. When they had only been on the market for a short time used transmissions were selling for as much as $4000. Now, thanks to the popularity and high sales numbers of this transmission the used market is flooded with units that need to be sold. Now it seems that it’s possible to find them for less than $1000.

[wrenchtech]

Originally Posted by EastCoastCB

PNW steve has a real nice Dodge diesel he was looking to sell. 5.9 with 6 speed manual. No swapping required.

Where would the fun be in that? The Ford trucks are good units and like a blank canvas. The stuff you can do them is pretty amazing. For example, the early super duty trucks (1999 - 2002) can except many of the parts from Ford trucks more than 10 years newer, body sheet metal, interiors, suspension, brakes.

Here is a picture of a 2002 Ford Excursion dressed up with a 2014 front end (love that paint scheme):

[EastCoastCB]

Originally Posted by wrenchtech

Where would the fun be in that? The Ford trucks are good units and like a blank canvas. The stuff you can do them is pretty amazing. For example, the early super duty trucks (1999 - 2002) can except many of the parts from Ford trucks more than 10 years newer, body sheet metal, interiors, suspension, brakes.

Here is a picture of a 2002 Ford Excursion dressed up with a 2014 front end (love that paint scheme):

Cummins with 6 speed > V8 with ford transmission. I'm pretty sure steve is asking about half what a conversion starts at.

[wrenchtech]

Originally Posted by EastCoastCB

Cummins with 6 speed > V8 with ford transmission. I'm pretty sure steve is asking about half what a conversion starts at.

You have piqued my curiosity. I will look into it.

[EastCoastCB]

I would, his stuff is NICE. I think he even has some real alcoas on the truck.

[slimbogatz]

Fummins,(ford w/cummins)check out Westin Champlin on ytube

[wrenchtech]

Originally Posted by slimbogatz

Fummins,(ford w/cummins)check out Westin Champlin on ytube

I’ve been watching him. He’s a hoot. I have to go back and look at his stuff again to glean some details.

I’ve got so much information coming at me and so much of it is incomplete or incorrect.

I found a truck salvage yard not to far away from me. They have a lot of schoolbuses in medium duty trucks. I’m sure they have whatever I need and they probably have the information I need to figure out what that is.

[Pullstart]

@wrenchtech have you made any progress or decisions in this project? I have a 2009 Blue Bird Vision with the 6.7/Allison combo and I’m feverishly trying to decide whether to pluck it and pop it into my rust free 2wd ‘01 Chevy 2500HD or to find a cool rwd car to stuff it into, or keep looking for another vehicle to put it in. I already have a 2wd diesel, so even though the allure of the swap is there, it wouldn’t really fit my needs or wants.