wrenchtech
Senior Member
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.
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.
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