[Wicked Mayhem]

My vague 4wd conversion thread. I've never done a thread like this. I'm sure others can chime in with some good info to add as I'm probably missing some points as I did most of the work a few months ago. I am not liable for anything you attempt to do to your truck. This thread is meant just as a guide to help you find the parts you need for this conversion. I am not responsible for what you do!!! I'm sure I'm forgetting a few things along the way, but I figured most of it out by searching the internet. So please don't PM me with a bunch of questions asking something that could easily be found if you even attempted a search. Not trying to come off as unhelpful, but I've gotten quite a few PM's over some fairly common sense stuff they are not searching for, and just asking me since Ive done it, and too lazy to search. I don't mind helping with some stuff if you're in a bind and cannot find answers.


Parts list of what you'll need. I'm listing the bare minimum things required to complete the job. While I did mine, I replaced u joints, cv's, hubs, did a few upgrades to the transfer case etc. since I was already here and didn't want to tear it back apart(the main parts i got were from a truck with 180K miles, and mine has 72K so i felt the need to go through everything. I got some parts from a guy off Craigslist from a truck he was parting out. Some parts new off eBay or gm, and some used parts off eBay. I don't have many part numbers. A lot of it I found by searching the part name so I didn't need a part number. If its not listed in this thread, then I don't know the number and you'll have to do some digging or search the name of the part.
From what iI understand everything from 01-07c uses the same 4wd parts (late 07-10 could be the same, do your research). Don't quote me on that as I'm not 100% sure. Most of my stuff came from a 05 LLY, and my truck is an 06 LBZ and I had zero problems. Your stock 2wd spindles are the same. All the front suspension, transmission crossmember, and torsion bar crossmember is the same, just missing some diff mounts. The crossmember by the lower rear control arm bushings is different. More on that later.. Parts list/stuff you need to do...


Front differential(no part number, fairly self explanatory. Mine is a 9.25" ring gear, will be money ahead to find one with the same gear ratio as your rear end to save you time and money)

CV axles

4wd Hubs(My 2wd hubs were solid in the center) from what Ive found, any aftermarket hub will be splined for 4wd. I recommend timken as I've read those are the best replacements.

Pass side diff mount/bushings. You have the rear hole in your frame already. You do not have the front bushing sleeve. You'll need to figure out a way to setup that front hole. I hole-sawed that hole out and welded in a sleeve for the bushing. I did mine like that so its just like factory. I made a jig up off a stock 4wd frame and transferred it to mine for location of that hole. I no loner have that jig before you ask. But if you were to hold up the bracket to the frame with the rear hole lined up, you can tell where the front hole needs to be. No idea on part numbers for the bushings as I got them with the frame clip iI bought and were in good shape.

This is the pass side diff mount. You will need to make the bushing mount that's to the left in this pic:

Here is the rear sleeve you already have in your frame:

This is the sleeve you'll have to fab up:

Here is the jig I made up to locate the hole:

Here it is on my frame:

After the outside part of the frame was piloted and whole sawed out, i tacked this solid bushing to the jig to locate the inner part to make sure it was perfectly square:

Then both sides are done:

Here is the sleeve my dad made for the bushing:

After I welded it in:

Rear bushing installed:

The mount with the stock studs wouldn't fit on the truck because the oil pan is in the way. So I knocked the studs out and had some bolts the right size to put in from the outside in, and then the pass side mount was complete:

You will also need to fab up the driver side mounts. I have pics posted below of how the look. The lower driver mount, you have half of already. Just need to make the other side of it so its double shear.
Here is an overview of the mounts:

Here is the upper driver side mount:

Here is the lower crossmember I was talking about.. Here is how the stock 2wd one looks:

Here is how the 4wd one looks:

I OPTED OUT OF MAKING THE DRIVER SIDE MOUNTS BY BUYING A LIFT KIT. It relocates the diff so it supplies the driver side mounts, and a spacer for the pass. side( so you still need to setup the pass side like factory) I used a 4-6" cognito lift kit so that's all i can speak for. Check with whatever lift you plan on buying to see how the diff mounts

Front and rear drive-shafts. Again I got lucky and got both from the donor truck off Craigslist.

4wd Tail-housing - 29544804 ( I think there is also another part number. I have the updated tail-housing that is supposed to be stronger. The p/n I listed is off merchants website. I found the new updated one alot cheaper off amazon)

4wd output shaft (#678 in daccoinc link)

Spacer p/n 29541013 (it replaces the tone wheel that speed sensor reads off of.) #845 in daccoinc link

http://www.daccoinc.com/pdfs/catalogs/ALLISON_1000_2000_2400.pdf

Tail-shaft and transfer case gaskets

Transfer-case. I would recommend the 263XHD. Its the push button version that requires no computer re-flash.(Again, that's what I was told) But if you run the 261XHD, you will have to have your computer re-flashed. Plus you don't have to cut holes in your floor, or worry about modifying your center console if you have one.

4wd push button controls for the dash(for 263XHD only) Mine was the 3 button(2hi, 4hi, 4lo) IDK anything about the one with auto 4wd, so don't ask.
TCCM(transfer case control module) it mounts up under the dash on the driver side near the emergency brake. It actually has a mount it goes in but i cannot locate one, or a part number so mine is zip tied up in there till i can find the correct mount for it. As for a part number on the TCCM, Ben told me to find one from the same year as my truck, and make sure the truck its coming out of has the same 4wd push button switch as what you'll be running. If you get one with a different setup then you, it MAY need reprogrammed, which is more money.

Wiring. I had two sections of the harness already from the donor truck. I chose to have someone build this for me. I have found a couple people who have done this swap and are using toggle switches to make the 4wd work, and cant go over xx mph or it will go into limp mode. I was not going to hack in a 4wd system like that and have to be careful on how it was used. Plus i wanted it all to look factory, and operate 100% like factory that away anyone who got in the truck didn't have to follow any strict guidelines on using the system. On my truck, all of the factory fuses are used, and looks 100% factory. I had Ben Tyler at BT DieselWorks - BT DieselWorks use my existing harnesses so he could modify them and make the rest from scratch. He did an awesome job. I would use him time and time again for stuff like this. Great quality work, and very helpful. Everything came labeled as to where to go. I had to splice in 3 wires inside, and plug one wire into the fuse box under the hood. The rest was plug and play like factory. No need to go into detail on the wires to hook up as yours could possibly be different, and he will go over all of that with you if you decide to go that route. I paid a little over 500$ for the harness setup but it was worth every penny. Yours could cost more or less depending on how much wiring you already have. Just throwing out a rough number as to what mine cost so your not shocked(several people have been when PM'ing me. You get what you pay for.)

Obviously fluids for front diff, trans, and t case.

I didn't list many part numbers, I know. But I got the majority of my parts from the donor truck so I didn't have to locate a lot. For the bare bones stuff needed to make the truck 4wd, I could have done it for right at 1800$(cheaper if i searched harder for used tail housing) But when I did mine, I bought new hubs, cv's, did the outer bearings and axle seals on the front diff, along with new pinion seal and crush sleeve. New u joints in both drive shafts, pump rub kit, tcase brace, new yoke on rear drive shaft, output shaft seal on t case, all new fluids in everything, and did the cognito lift to simplify welding on brackets, and not wanting to lower the truck back down to stock height, or cranked/leveled with bad angles. So all together im in it for almost 4K. But everything that looked like it had any wear, has been freshened up. And its all been apart so i have better peace of mind knowing its good to go. Even at 4 grand, I couldn't buy a factory 4wd truck in the condition mine is in, with the miles mine had on it when i bought it a little over a year ago(59K miles) for that 4 grand i spent. And I came out with a lift kit and all sorts of upgrades lol.

Here's a few other random pics of the swap:

If i notice any info i looked over is missing ill add it in, and if anyone has tips on anything feel free to post or correct me. I wish i had good pics of the trans work but when i get in the middle of a job the last thing i think of is taking pics. Like i said this isn't a 100% step by step how to on doing this job, just mainly for a guide on the parts needed. If you have much mechanical ability at all you wont have any troubles doing this conversion.

 

[Max 1.6]

As for the tranny tail housing, do you really need the spacer? Or can you just reuse the 2wd toothed spacer?

For the t-case, everywhere I read they suggest the 261 which is manual. The manual one does not seems to require wiring. You talk about reprogramming, can you elaborate?

Thanks

 

[J&N cattle]

Very good thanks

 

[Willie friesen]

Did you ever figure out if the spacer was needed?