Cummins swap a deuce

[M109A3HQ-6]

Looking for anyone who has Cummins swapped a deuce. We are picking up our M109A3 the 1st of February and starting to conversion to a RV. We are considering swapping to a mechanical Cummins with a two wheel drive manual trans. Really don’t need info on how to do it just looking for real world info on the results good, bad, indifferent. I am retired military and know a fair bit about these trucks as well as building jeeps and motor swaps I am a skilled fabricator and mechanic knowing the weight difference I know a clutch upgrade will definitely have to happen. But how does the transfer case like the added torque axles are well known to handle the power I.e, they have been in high hp offroad rigs for years, but not down the highway for long periods of time though the have been in dump trucks and road tractors for years. But I think its just The center section and not the specific axle housing’s. The deuce axle has 6.72 ratio and might not like long use.

Any guidance you all can give would be grateful to receive.

 

[cbrTodd]

Youtube user Tactical Repair (also a member here) did a 5.9 12 valve swap and documented the results in one of his videos after a pretty lengthy first trip. I think he has had a few minor-ish issues but you can watch and form your own opinion. He has lots of videos from during and after the upgrade.

 

[cbrTodd]

Since you brought up using a different transmission, just know that it seems to be one of the more aggravating parts of the swap. If you're planning on using the NV4500 from a dodge truck, I think they are rated a bit lower than the spicer 3053a that is in a stock m35a2 but they aren't much longer, allowing you to keep the flywheel close to its original location. And using the pickup engine mounts makes it really tight to run an air compressor, although I have seen it done at least once (not on a deuce). Anything else I have heard of that keeps an OD ratio close to the 0.78 of the 3053a is longer, making you move the engine forward and cutting out room for the intercooler. Tactical Repair has an 0.69 ratio gear set in his 3053a that is no longer made, so that's not something you are likely to find. You could push the transfer case farther back, but that's a bit of work too.

There are a handful of swap threads on here too that can show what others have done if you're interested.

 

[M109A3HQ-6]

Since you brought up using a different transmission, just know that it seems to be one of the more aggravating parts of the swap. If you're planning on using the NV4500 from a dodge truck, I think they are rated a bit lower than the spicer 3053a that is in a stock m35a2 but they aren't much longer, allowing you to keep the flywheel close to its original location. And using the pickup engine mounts makes it really tight to run an air compressor, although I have seen it done at least once (not on a deuce). Anything else I have heard of that keeps an OD ratio close to the 0.78 of the 3053a is longer, making you move the engine forward and cutting out room for the intercooler. Tactical Repair has an 0.69 ratio gear set in his 3053a that is no longer made, so that's not something you are likely to find. You could push the transfer case farther back, but that's a bit of work too.

There are a handful of swap threads on here too that can show what others have done if you're interested.

What’s the chances of someone on here being able to find a OD kit. The Cummins is almost 10” shorter than the multi fuel not to mention I’m not to bad a fabricator. Hanse the research before hand. Best to learn from others mistakes before making the same ones myself.

 

[cbrTodd]

Chances of finding one of the 0.69 ratio OD kits unused at this point are near zero. I think it was less than 100 kits made to begin with, by another member here, and the last time someone placed an ad asking for one it went unanswered. You could try though.

Yes the shorter length of the 5.9 compared to the multi fuel will help. I suspect the gap goes away quicker than anticipated though. From measurements planning for my own swap (had the engine on a stand for 5 years now after rebuilding it, just haven't started the process to put it in yet), once I added the clutch fan that came on the F800 with the engine and the intercooler in front of the radiator, along with the extra depth of the SAE 2 to SAE3 adapter on the #2 housing on my engine, most of it is gone.

 

[M109A3HQ-6]

Chances of finding one of the 0.69 ratio OD kits unused at this point are near zero. I think it was less than 100 kits made to begin with, by another member here, and the last time someone placed an ad asking for one it went unanswered. You could try though.

Yes the shorter length of the 5.9 compared to the multi fuel will help. I suspect the gap goes away quicker than anticipated though. From measurements planning for my own swap (had the engine on a stand for 5 years now after rebuilding it, just haven't started the process to put it in yet), once I added the clutch fan that came on the F800 with the engine and the intercooler in front of the radiator, along with the extra depth of the SAE 2 to SAE3 adapter on the #2 housing on my engine, most of it is gone.

Thank you for the video link the trucking company I drive for and will be returning to in order to drop the rig off is in Indianapolis. I will be there to drop of the rig when I retire around the 1st of February wouldn’t mind meeting you if given the chance. Let me know other wise thank you again for all the help.

 

[cbrTodd]

Thank you for the video link the trucking company I drive for and will be returning to in order to drop the rig off is in Indianapolis. I will be there to drop of the rig when I retire around the 1st of February wouldn’t mind meeting you if given the chance. Let me know other wise thank you again for all the help.

I sent you a PM with contact info. We'll see if we can make something work.

 

[HanksDeuce]

I'm not sure if you read my response to the conversation you started with me, so I'll post my reply here.

My 6BT came out of a Peterbuilt chassis that was under a Thomas built bus. It was engineered for 30,000 lb GVWR. Not sure on what clutch you would have to use as my Cummins is mated to an Allison AT545. I never broke the engine apart from the transmission when I re-powered my deuce with that combo.

I don't have any issues driving the weight of my deuce with this engine/transmission combo (13.5K lb). Top speed is gear limited to 55 mph because of the non-lockup torque converter and no overdrive. I haven't touched the fuel plate on my Cummins. She doesn't roll coal at all.

Let me know if you have any other questions. You can find a lot on my personal website, www.hanksdeuce.com.

 

[montaillou]

once I added the clutch fan that came on the F800 with the engine and the intercooler in front of the radiator, along with the extra depth of the SAE 2 to SAE3 adapter on the #2 housing on my engine, most of it is gone.

Easy to run out of room.