2wd to 4wd conversion

This topic has probably been pounded to death but here it is again.

I was planning on building a 3/4 ton 4wd pick up from the ground up. I just got the axles under the chassis and got it rolling. .
The body was shot, the only donor truck I could find with a decent cab was an 86 1 ton dually 2wd with a flat deck dump.

After some a lot of time and thought. The dually is just to cool and too good of shape to scrap for a cab and leave to rot.

So wadda I wanna do is give it a straight axle front end and lift, put some nice wheels and tires on it and a good paint job. In reality, that's all it really needs.

Ive read a lot of threads about the easiest way is to frame swap, but that's out the window here cause the amount of trucks and donors around here is slim to none as it is.

But I have the brand new lift springs and lift kit for the 3/4 ton, straight axle, gear box, transfer case, straight axle everything this for a 4wd.

Is it possible? Is it just a matter of putting spring hangers in the right position? Same for shock mounts?

Thanks for any info, pointers or direction, all greatly appreciated

Look at ORD. Great Reference.

https://www.offroaddesign.com/

Craig 85 said:

Look at ORD. Great Reference.

https://www.offroaddesign.com/

Click to expand...

Thanks appreciate it

its possible but yuore still gona need a donor frame chasis for all the tons of parts pieces to do it... you literally are gonna need anything and everything that attaches to the frame, riveted and bolted..... ppl dont see to understand just how much different 4x2 and 4x4 chassies are.. 1 ton rear packjs are 40 apart, anything else is 42.5 apart which is differetn leaf hanger frame brackets, and then in the fornt the 2wd susp engine cradle needs to be totally unbolted removed and put in 4x4 chassis parts brackets for 4x4 and motor mounts, and the shackles etc go through the frame rails on 4x4 frames.. and rad suport mounts brackts need cut off and swapped and it goes on from there... dually rear and non DWR in front? your PTO driveshft wil need modified since it wont be on tranny any more... is it 4 speed? hope PTO is on same side of transfer case, as it was on the tranny

Sure it's possible. Try to get a k20 frame and drop the stuff you have in. Otherwise lots of work and headache.

ali_c20 said:

Sure it's possible. Try to get a k20 frame and drop the stuff you have in. Otherwise lots of work and headache.

Click to expand...

I have a 4wd donor frame that I was originally gunna make a truck out of but it's pretty thin and holy.

I had the complete 1 ton dually there, running and driving except for brakes. Little rough around the edges.


They both share 56" springs in the rear, that was a bonus. So I figured why not swap in in front spring hangers, add a straight axle. Disregard the dump and swap in another gear box and transfer case and ditch the granny low gear box, put all new brakes and brake lines on.

I imagine I'd have to swap in the cross member for sway bar aswell.

I found some pics of c and k frames.

Look at the 4x4 schematic...
Notice where the rear shackle (front suspension) mounts right over the point where the frame begins to sweep upwards.

On the 2x, the frame begins it's upward sweep a but further back, toward the rear.
If you mounted the rear spring shackle where it needs to be on the 2x frame, it would be hanging from the sweep. There would be no room for the spring to compress and swing the shackle rearward.

You can use the ORD bracket kit or the superior DIY4x4's B51 kit with a 51 or longer REAR spring.

shiftpro said:

Look at the 4x4 schematic...
Notice where the rear shackle (front suspension) mounts right over the point where the frame begins to sweep upwards.

On the 2x, the frame begins it's upward sweep a but further back, toward the rear.
If you mounted the rear spring shackle where it needs to be on the 2x frame, it would be hanging from the sweep. There would be no room for the spring to compress and swing the shackle rearward.

You can use the ORD bracket kit or the superior DIY4x4's B51 kit with a 51 or longer REAR spring.

Click to expand...

I'm not seeing much difference. If you look at the 40" distance between the wheel centerline and the gauge hole, the upsweep begins and ends in the same areas of that 40" distance.

I've seen factory 2wd frames converted to 4x4 using all factory parts, it's plenty doable and the frame has a profile that works. One thing that is noticeably different though, is the bottom flange on the 2wd frame. It is wider than a 4x4 frame and needs trimmed down for shackle clearance. The 2wd frame also has the e-brake cable mount flange right about where the 4x4 upper shackle mount needs to go. But that can be overcome as well.

bucket said:

I'm not seeing much difference. If you look at the 40" distance between the wheel centerline and the gauge hole, the upsweep begins and ends in the same areas of that 40" distance.

I've seen factory 2wd frames converted to 4x4 using all factory parts, it's plenty doable and the frame has a profile that works. One thing that is noticeably different though, is the bottom flange on the 2wd frame. It is wider than a 4x4 frame and needs trimmed down for shackle clearance. The 2wd frame also has the e-brake cable mount flange right about where the 4x4 upper shackle mount needs to go. But that can be overcome as well.

Click to expand...

It's hard to see, but the upsweep starts sooner on the 2x, and it's not as steep either. There is simply no way you can bolt 4x parts to this and make it work. Frame width is not an issue.
Look at the 2x plan.. Look where the upsweep begins... it starts right above the 'G' in the word gage. That's where the shackle would have to be to have the room to swing back when suspension compresses. It's even worse if you try use a lift spring with any arch to it. As you know, when you flatten an arch it gets longer.
A 51" spring would be mounted further back, just below where the sweep starts on 2x. Of course, the front spring mount also needs to get moved forward.

I saw a 2x converted with stock front end parts... he cut the front of the frames off and welded the 4x front end to his 2x. His 4x4 frame had massive rust on the rear end and broken frame so flame wrench came to the party.

If you don't believe me give ORD a call... or if you're feeling it, go to Pirate and start a thread saying you can do this! LOL that might be fun!

And I should mention, using a B51 kit and longer spring puts the entire spring pack lower than the factory position. So there is lift right there.
The DYI parts, B-51 and beyond allow you to use a 56" spring too, but this setup shouldn't really be on the road. Maybe of it had an anti-swaybar, but the whole idea is massive suspension travel for rock crawling. Any larger than a 52" spring is too flexy for street use, basically.
Why use an anti-swaybar when you are making 12" of travel for serious off roadage...

shiftpro said:

It's hard to see, but the upsweep starts sooner on the 2x, and it's not as steep either. There is simply no way you can bolt 4x parts to this and make it work. Frame width is not an issue.
Look at the 2x plan.. Look where the upsweep begins... it starts right above the 'G' in the word gage. That's where the shackle would have to be to have the room to swing back when suspension compresses. It's even worse if you try use a lift spring with any arch to it. As you know, when you flatten an arch it gets longer.
A 51" spring would be mounted further back, just below where the sweep starts on 2x. Of course, the front spring mount also needs to get moved forward.

I saw a 2x converted with stock front end parts... he cut the front of the frames off and welded the 4x front end to his 2x. His 4x4 frame had massive rust on the rear end and broken frame so flame wrench came to the party.

If you don't believe me give ORD a call... or if you're feeling it, go to Pirate and start a thread saying you can do this! LOL that might be fun!

Click to expand...

I believe you that the frame profile is different. But it is close enough that you can indeed use factory parts for a 4x4 conversion. I don't need to call ORD, I have seen it done more than once and it is possible to do. I have seen it done on Pirate too, so I don't need to go posting it there. And with my current schedule, it's going to take a good long while to finally get it done, but I will be doing the swap as well. I'm just not going to use the factory crossmember, I'm using an ORD unit because the factory crossmember kinda sucks. You can bet your sweet biscuits that I will make a thread about it too. But it will be here.

shiftpro said:

It's hard to see, but the upsweep starts sooner on the 2x, and it's not as steep either. There is simply no way you can bolt 4x parts to this and make it work. Frame width is not an issue.
Look at the 2x plan.. Look where the upsweep begins... it starts right above the 'G' in the word gage. That's where the shackle would have to be to have the room to swing back when suspension compresses. It's even worse if you try use a lift spring with any arch to it. As you know, when you flatten an arch it gets longer.
A 51" spring would be mounted further back, just below where the sweep starts on 2x. Of course, the front spring mount also needs to get moved forward.

I saw a 2x converted with stock front end parts... he cut the front of the frames off and welded the 4x front end to his 2x. His 4x4 frame had massive rust on the rear end and broken frame so flame wrench came to the party.

If you don't believe me give ORD a call... or if you're feeling it, go to Pirate and start a thread saying you can do this! LOL that might be fun!

Click to expand...

Here we go, this time with pictures.
This is a C10/20 frame:


And this is a K10/20 frame:

^In the case of those two, the K frame actually has a little less room for shackle clearance, compared to the C frame.

Now here's where the bigger differences lie, the C/K 30 frames. Here is a K30 frame:

As can be seen, there's very little clearance for a positive arch spring.

And when you take a C30 frame and convert it to 4x4 with factory parts, clearance is still tight, as can be seen here:

Clearly it's possible and has been done. This one in particular would have more clearance if the installer had moved the shackle hanger down some and rotated it to the factory angle. Plus, installing the updated shackles that are 1/2" longer would gain a bunch of clearance too.

bucket said:

Here we go, this time with pictures.
This is a C10/20 frame:

You must be registered for see images attach

And this is a K10/20 frame:

You must be registered for see images attach

^In the case of those two, the K frame actually has a little less room for shackle clearance, compared to the C frame.

Now here's where the bigger differences lie, the C/K 30 frames. Here is a K30 frame:

You must be registered for see images attach

As can be seen, there's very little clearance for a positive arch spring.

And when you take a C30 frame and convert it to 4x4 with factory parts, clearance is still tight, as can be seen here:

You must be registered for see images attach

Clearly it's possible and has been done. This one in particular would have more clearance if the installer had moved the shackle hanger down some and rotated it to the factory angle. Plus, installing the updated shackles that are 1/2" longer would gain a bunch of clearance too.

Click to expand...

Thank I appreciate this. I would think the model/brand of spring would become important, as the rear eye would have to be on the small side to fit in there. I've heard of notching the frame for spring eye clearance. If using the stock forward spring mounts, I imagine is could be shimmed to hang the spring a little lower to compensate for lowering the rear of the spring. It would certainly get tight quick with an arched lift spring, as it not only moves back but up.
Sure, anything can be done with a flame wrench, big effin hammer and the right attitude I guess..
I would also be concerned about the clearance between the spring/axle mounts and the bottom of the frame. The 4x frame has a little more clearance in this spot too. But with a lift spring this would become a non-issue.

I think there might be a few other issues to deal with. For example (I think) the rear cab mounts on a crew cab 2x are different than 4x crew cab.

And take note this conversion you were so kind to show would only work with stock length springs. a long spring like a 52 would need the front mounts moved more forward. I believe the whole concept is really about hanging a longer spring for massive travel... which in reality is just more droop. Droop is where it's at in keeping tires on the ground!

You have inspired me to look a little deeper into this. I want to convert Big Blue (avatar <<) to 4x4. I have a K30 4x4 frame but the rear is so rusted. And Blue doesn't have any rust at all. Also I wouldn't hesitate to notch the frame a bit. This truck would be multi purpose and I'm not interested in 52s for it. Plus I have Tough Country 4" HD springs waiting...
Thanks again.