(Maybe) A 2006 3.7-5.7 Swap

[Fishstickz]

So I’ve had something placed in my lap the past few days. A wrecked 2008 1500 2wd with a hemi at a local salvage.

So I’m considering buying the whole truck and (possibly) going thru with an engine swap at some point. I know that based on the 2004 v6-hemi swap thread, the 3.7 and the 5.7 dont share many parts. Because of that I figured it would be best to buy the whole vehicle rather than just the motor. Plus, I’ll have access to other parts that I may feel like swapping over someday (power windows and locks anyone?)

This deal is nowhere near final, so this may or may not happen (and the opinions on this thread will likely help make part of the decision as well)

1) Is there anything really different with the 2006 and 2008 model years? Electronics and everything? I know 2006+ has CAN-bus but other than that I’m not sure of all the possible differences between the 2 years

2) If I was to go thru with this, would it be best to send my 2006 TCM to get reprogrammed for a hemi, or swap in the 2008 TCM?

3) I have a regular cab and the other truck is a quad cab. I don’t think it would cause problems in the engine compartment but I’d rather ask people who are more knowledgeable on the subject

4) Since I have a later model V6, it comes paired with a 4-speed 42RLE—basically a weak RFE. I’ll have to replace it with a 545RFE. Is there anything else in the drivetrain that would possibly need some attention? They’re both 2WD so I won’t have to mess with T-cases or diff gears.

Anyways, before anyone calls me crazy, my perfect world thinking is to buy the truck (providing it all checks out and they don’t highball me on a price) take the hemi out, inspect it, and replace what needs to be replaced and also maybe add a couple of performance goodies while I have it tore down. Then sometime down the road, bring the truck in when I have a week or so of free time to get it done, and get everything swapped.

I’d like to add my V6 is running great with 146k miles. My 3.7 is by no means on its last legs and I probably wouldn’t get around to the actual “swap” for at least another year or so. I’m definitely not wanting to rush into something like this cuz mistakes are made when you have to rush a lengthy project such as this. In other words, I’d like to take my time and ensure I did it right. So any opinions are appreciated



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[ST-8]

Buying the whole truck would be ideal so you can swap the computer stuff over, I’ve seen where 4.7 pcms will work on the hemi idk about 3.7. You have a 9.25 rear so your good there idk about your driveshaft working since it’s the 42.

Make sure you have another sense of transportation would be one of my suggestions

 

[HemiLonestar]

So I’ve had something placed in my lap the past few days. A wrecked 2008 1500 2wd with a hemi at a local salvage.

So I’m considering buying the whole truck and (possibly) going thru with an engine swap at some point. I know that based on the 2004 v6-hemi swap thread, the 3.7 and the 5.7 dont share many parts. Because of that I figured it would be best to buy the whole vehicle rather than just the motor. Plus, I’ll have access to other parts that I may feel like swapping over someday (power windows and locks anyone?)

This deal is nowhere near final, so this may or may not happen (and the opinions on this thread will likely help make part of the decision as well)

1) Is there anything really different with the 2006 and 2008 model years? Electronics and everything? I know 2006+ has CAN-bus but other than that I’m not sure of all the possible differences between the 2 years

2) If I was to go thru with this, would it be best to send my 2006 TCM to get reprogrammed for a hemi, or swap in the 2008 TCM?

3) I have a regular cab and the other truck is a quad cab. I don’t think it would cause problems in the engine compartment but I’d rather ask people who are more knowledgeable on the subject

4) Since I have a later model V6, it comes paired with a 4-speed 42RLE—basically a weak RFE. I’ll have to replace it with a 545RFE. Is there anything else in the drivetrain that would possibly need some attention? They’re both 2WD so I won’t have to mess with T-cases or diff gears.

Anyways, before anyone calls me crazy, my perfect world thinking is to buy the truck (providing it all checks out and they don’t highball me on a price) take the hemi out, inspect it, and replace what needs to be replaced and also maybe add a couple of performance goodies while I have it tore down. Then sometime down the road, bring the truck in when I have a week or so of free time to get it done, and get everything swapped.

I’d like to add my V6 is running great with 146k miles. My 3.7 is by no means on its last legs and I probably wouldn’t get around to the actual “swap” for at least another year or so. I’m definitely not wanting to rush into something like this cuz mistakes are made when you have to rush a lengthy project such as this. In other words, I’d like to take my time and ensure I did it right. So any opinions are appreciated

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1) In so far as the type of electronics, no. In so far as the elex that controls the engine and trans? Yes.
2) The 2008 doesn't have a TCM. The hemi uses a combined PCM that controls both. You can't use anything trans wise from your truck trying to put a hemi in it.
3) Won't matter other than driveshaft length.
4) 42RLE is a totally different transmission, not even remotely related to the RFE (who told you that?). 42RLE started life as a FWD transaxle and some idiot thought that it would be a good idea to make it a RWD/4WD transmission. As Liberty owners have found out (the hard way), you get it just a touch too warm and it dies, not to mention being inherently weak.

It is possible you can pull this off having the entire donor truck, but don't enter into this lightly. You are going to be pulling and transferring all kinds of harness and computers, not to mention engine, transmission, driveshaft, fly-by-wire (APPS) system for the hemi TB (yours is cable driven), exhaust system, etc etc. You will need detailed wiring diagrams for both years because there WILL be harness differences here and there. You'll need to either swap the steering column over or the SKIM if you don't want your new PCM to lock out. Unless you replace EVERY module in your truck with the donor, there's a better than even chance you will run into VIN mismatches, which at best cause errors and malfunctions and at worst cause non-function. You'll also have to match the cooling system to the new setup.

 

[Fishstickz]

1) In so far as the type of electronics, no. In so far as the elex that controls the engine and trans? Yes.
2) The 2008 doesn't have a TCM. The hemi uses a combined PCM that controls both. You can't use anything trans wise from your truck trying to put a hemi in it.
3) Won't matter other than driveshaft length.
4) 42RLE is a totally different transmission, not even remotely related to the RFE (who told you that?). 42RLE started life as a FWD transaxle and some idiot thought that it would be a good idea to make it a RWD/4WD transmission. As Liberty owners have found out (the hard way), you get it just a touch too warm and it dies, not to mention being inherently weak.

It is possible you can pull this off having the entire donor truck, but don't enter into this lightly. You are going to be pulling and transferring all kinds of harness and computers, not to mention engine, transmission, driveshaft, fly-by-wire (APPS) system for the hemi TB (yours is cable driven), exhaust system, etc etc. You will need detailed wiring diagrams for both years because there WILL be harness differences here and there. You'll need to either swap the steering column over or the SKIM if you don't want your new PCM to lock out. Unless you replace EVERY module in your truck with the donor, there's a better than even chance you will run into VIN mismatches, which at best cause errors and malfunctions and at worst cause non-function. You'll also have to match the cooling system to the new setup.

The pleasures of posting late at night is lots of typos lol, I apologize I meant the PCM. For some reason I was thinking TCM meant totally integrated power..or something like that idk

As for the transmissions, i knew they were completely different but I think my exhausted self worded it badly, so i apologize again lol

You do bring up some really good points I overlooked before that would seriously complicate any engine swapping. I’m sure it can be done with the right amount of tools, experience, and time but I’m severely lacking in all 3 right now so I figure this sort of project is better suited for down the road if at all lol

Anyways, thanks for the reply!


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[HemiLonestar]

No problem, most people don't realize how involved something like this can be, even if you have the entire donor vehicle. I've lost count of how many "I wanna do this" posts I've seen here and other forums (both cars & trucks) and very few if any get seen to the end. Like you said, anything is possible given the resources, but it's not like the old days. About the only real "easy" successful swaps are the ones where it's the same engine family.