Okay I am doing a engine swap next month over thanks giving and am replacing my 3.9 with a 5.2. I know that since my current tranny has 217k+ miles on it I will need to start looking at getting it rebuilt or replacing it. I went to rock auto just to see how much they could charge I got confused. On both the 3.9 and the 5.2 it list the 42re as rear wheel and the 44re as the 4x4. My truck is 4x4 and when I had sent my vin to find out what my truck came with from the factory it says that I have the 42re. They are the same price but my question is how hard would it be to jump up to the 44 since it says thats for 4x4 or would the 42re work just fine even though it just says rear wheel drive? Any help would be appreciative since I am new at the whole transmission replacing.

 

42 is for V6, 44 is for 5.2, 46 is for 5.9. The internals get bigger with each step. The 46's rotating assembly weighs significantly more than the 42's so that there is not as much power absorbed in trying to turn them. The less power it takes to turn the transmission, the more can get to the wheels. As far as I know, all the output shafts are the same, so the transfercase should be universal, just change the transmission. What does matter is that it's easier to just find a 4x4 44RE so that you aren't swapping tailshafts and tailhousings off a 2wd 44RE.

 

So if I go with the 44re would I have to change the TCM as well or will my current one work with it?

 

Magnum Pushrod motors dont have a TCM, only the PCM. The Hemi and OHC engines have a TCM. Electrical connections are the same for 42/44/46RE.

If you wanted to go beefy, you could put a 4x4 46RE in it and be done. I'd like to put a 46 in my 3.9 when I shell the 42, but I know I's probably lose 10-15 HP turning the bigger internals. Alot of racers run the Torqueflight 904 (hydraulic 42RE) instead of the 727 (hydraulic 44/46RE) for this reason, puts more power to the wheels in trade for servicing the transmission a little more often from burned out bands and clutches.

 

Just FYI, 96 Dak. 4wd 5.2 came with the 46RE. (At least mine did.) Your wiring & PCM should work just fine.

If you have the choice, get the 46. I wouldn't use the 42, I think it's inviting trouble.

 

a V8 will blow through the 42's bands and clutches in no time. The local guys that run 904's behind the big small block mopars and small big block mopars are changing clutches and bands about twice a season.

 

Okay, thanks for the info and advice. Since I'm swapping to a 5.2 I might look into the 46re. I'm just praying that I can baby the 42re so I can at least make it back from Utah to Colorado after my swap or at least long enough for me to get the money for a new tranny.

 

Another question, where would a good place be to get a new one? Shipping wouldn't be a problem since I have it delivered to my work.

 

depends on what you want to pay. You can get one from the junkyard and have a reputable shop go through it, or you can order one online from a transmission shop or racing shop.

 

I would like to get probably a reman one so I can just pull the old and put the new in. If I went with the 46re is there anything that I would have to change or would it just bolt right up?