I have found a few posts talking about motor and tranny swaps in trucks, but nothing that totally clears it up for me. Sorry if anybody gets upset about me asking this. I have a 99 ram 1500, 5.2l. Dropped the pan on the tranny today and found some stuff that def shouldnt be there. I am just curious if I found a 5.9l and tranny combo, could I drop that in my truck. What exactly would I need extra, or do for it to work?

 

I've never done this , but from lurking on here a lot, I believe you will need a pcm for year of donor motor and tranny, unless you can get that off the same truck. But still will have to be flashed to your vin. That's all I know. Some others will chime in tomorrow morning.

 

Transmission is plug and play. A transmission from a 5.9 work fine with your 5.2 and it's computer. If you switch to the 5.9 engine, yes you will need to swap computers with it and if you want it to be correct, have it flashed.

 

Swap the PCM as well, or, just get a tuner for the 5.9, and reflash your existing computer. Wiring harnesses are the same. It's a direct drop in.

 

what about transfer case?

 

Transfer case will work fine. You will only need the PCM or have yours flashed like others have said.

 

all you need to solve the pcm issues is a sct tuner from hemifever, and have him load tunes for a 5.9 instead of a 5.2

 

In theory wouldn't a tuning program for a 5.9 also work for a 5.2? They're basically the same motor with the only difference being displacement. Or am I off my rocker here?

 

Someone here put a 408 in with a stock PCM & got it running & driving on the stock tune. Of course they did get it flashed afterwords but the stock PCM will work fine for you as is. It is plug & play. You dont need to do anything with the original PCM as long as its all the correct yrs for interchanging.

 

Petea- you are right to a point.. The fueling is the issue there... it will run but it wont be perfect..

Astested- thats not the entire truth. If swapping the PCM with another it HAS to be flashed with the trucks vin or you will have constant codes coming up..