How difficult to convert 2wd to 4wd?

[Cummins4Life]

I was looking at a 3/4T Dodge Cummins crew cab... BUT it's a 2WD instead of a 4x4. 1st generation Cummins crew cabs are pretty rare so I am curious what is involved in making a 4x2 into a 4x4 since I have never done it before... so what all is involved? It has an auto transmission, which I might consider swapping for a NV4500 5spd. So I believe I'd be buying a new front axle($$?), transfer case($$?) and possibly a transmission... plus springs and???? I haven't done this kind of thing before but I think I am capable doing a lot of the work myself.

Any thoughts?

 

[Philip]

Best way it to buy a donor vehicle for all the parts you need. If you try to scrounge up every little part. It can run into more money than buying a donor to strip.



The basic frame is the same between the two. The holes are prepunched on the frame so a bare frame could be used for eather app. The hard part is the size of everything. You need a pretty good sized shop where you can park both side by side to make the change over easyer.

 

["Mad Max"]

2x4 - 4x4 swap

Zach -

I did this conversion to my dually (readers rigs). It is very doable, and Philip is right about the donor, or at least a good source of parts.

Essentially you cut off everything related to the front suspension and toss it - just don't harm the frame. Then you bolt up everything 4x4 related. The donor vehicle will have the brackets, bolt locations, etc.

One very critical piece of the engine crossmember. On my big block (gas engine) conversion the 2x4 and 4x4 don't share the same cross member. This piece has to be swapped, and if memory serves the bolt/stud holes aren't predrilled between 2x4 - 4x4 frames. 2x4 has holes for 2x4, and same for 4x4. This will require very precise measuring and careful templates - but it's just nuts and bolts after that. Not sure if a 4x4 Cummins X-member is different than a 2x4 one, but I bet the cost of an XH-35 that it is.

If you want to keep the 2x4 transmission you will need a divorced transfer case with an intermediate drive shaft in between, and I would recommend nothing less than a NP205 transfer to hold up to even a stock Cummins.

You will need custom length driveshafts, and you may need 3 of them, including a 2-piece rear with a carrier bearing. On my dually I used the t-case 'as' the carrier bearing - works fine, and moved the t-case about 2 feet rearward and made a longer front shaft. In retrospect I would have done a 2-piece rear shaft, left the t-case where it was, and kept the front shorter.

You will probably want to find a Dana 60 front, and I'd recommend finding one with an 8-bolt outer hub - this will allow you to swap out the outer hub and replace it with a lockout hub like a Superwinch or Warn hub - The NP205 t-case is not a shift-on-the-fly case, so you have to stop to put it in 4wd anyway. If you don't find an 8-bolt outer hub cover version you will end up with a full-time 4x4 front axle. Okay for back roads but not great for highway/pavement, unless you like buying lots of tires.

You can expect to spend about $1000-1300 for a good, fresh D60 front end, and the hubs are about $200. A good NP205 with a rebuild is about $500-750 if you can find one locally. The NV4500 5-speed conversion from Quad 4x4 is about $3000, not including the pedals, linkage, bellhousing, flywheel, etc - their kit assums you already have a Getrag to start with, but the 5-speed is fresh and upgraded. I'm putting one behind my Cummins sooner or later - (I just like to shift)

There is a lot to this swap, but in the end it's just nuts and bolts (grade 8 of course, and lots of loctite).

Philip is also right about the space for doing the job - don't try something like this lying on your back - park them side by side in a warm garage with lots of air tools, beer, bandaids, and make sure it's out of earshot of the kids because you will be swearing, a lot.

Just enough to wet yer appetite, ja?!

- Suerte!

Sam

 

["Mad Max"]

4x4 parts abound!!

Zach -

I am doing the Monster Garage thing on my dually - I am taking it completely apart, and I will no longer need any of the 4x4 parts, including the Skyjacker Softride springs (4"-over fronts, 6"-over rears), that I needed to do the conversion.



Not sure where you are in your project, but if yer looking to do the swap gimme a holler, because I got everything you're going to need, and it's allll there.



So you know, I'm selling it all because I'm doing some very, very custom suspension stuff that will look nothing like the factory. Nothing wrong with any of it, and I can send you some pics of what it all looks like. The engine/trans/front clip are all off so everything is easy to see.

Hasta,

- Sambo