LBZ: 4WD Conversion

[Wicked Mayhem]

Im converting my truck to 4WD. Ive never messed with an allison transmission. From what ive read, i have to pull my trans out and stand it up on the bellhousing to do the work. truck has 72K miles. I did transgo/filters and transdyn at 64K miles.

I have bought...

-new 4wd tailhousing
-4wd outputshaft/nut
-pump rub kit, brace
-fluid/spin on filter
-near new electronic transfer case
-driveshafts/new u joints
-4wd push button controls
-transfer case control module
-ben tyler made me a harness for my truck for the 4wd to all work like factory.

Is there anything im missing parts wise? Is there any tips or tricks to swapping output shafts? I bought an allison manual too, but it doesnt go into a bunch of detail on what im doing really. Anyone have pics of this area of the trans? I like being able to see pics of stuff like this before i jump into it. From what ive read its fairly straight forward. Main thing im making sure of is i dont need anymore parts before its tore down.

Thanks!

 

[Chevy1925]

gunna be hard to get power to the front tires without a diff or cv axles. you will also the need all teh brackets for the diff to bolt into that are welded onto the frame or get a whole front frame section and weld it to yours

 

[ScreaminDuramax]

This should be sweet. Id like to know at the end how much this all cost. Everyone always says buy a new truck, but this might prove some wrong.

 

[Chevy1925]

This should be sweet. Id like to know at the end how much this all cost. Everyone always says buy a new truck, but this might prove some wrong.

its been done on two trucks here on DD. one on a regular cab, the other a crew cab. i cant say what their opinion was but knowing the amount of work to do it, unless you have a truck with an extensive amount of work into it already and have a bad issue with getting attached to your truck, your better off buying one with 4wd

 

[Wicked Mayhem]

gunna be hard to get power to the front tires without a diff or cv axles. you will also the need all teh brackets for the diff to bolt into that are welded onto the frame or get a whole front frame section and weld it to yours

LMAO yeah i was mainly asking transmission/transfer case wise what i needed. I have the front diff. I need to buy new cv's and im gonna obviously have to get rid of my 4" spindles. Im gonna do a 4-6 cognito and run it hopefully fully decranked. That will take care of the diff mounts on the driver side. I already have welded a sleeve in the driver side frame my dad machined and have the pass side diff mount on the truck.

This should be sweet. Id like to know at the end how much this all cost. Everyone always says buy a new truck, but this might prove some wrong.

Thanks, i will tally it all up in the end. I got a good deal(IMO) on tcase, front diff etc... And yeah most of the people say buy a new truck, itll be cheaper. But I wont be able to buy a 4wd truck with the miles mine has, in the shape its in for what i can do the conversion for. And i follow you on IG lol

 

[Wicked Mayhem]

its been done on two trucks here on DD. one on a regular cab, the other a crew cab. i cant say what their opinion was but knowing the amount of work to do it, unless you have a truck with an extensive amount of work into it already and have a bad issue with getting attached to your truck, your better off buying one with 4wd

I 100% disagree with that lol. Find me a 4wd ccsb dmax, clean as hell, with 59-72k miles in texas for 22K. My truck doesnt have major mods, but its stuff id rather not do again. This type of work converting to 4wd is no biggy to me.

 

[Chevy1925]

I 100% disagree with that lol. Find me a 4wd ccsb dmax, clean as hell, with 59-72k miles in texas for 22K. My truck doesnt have major mods, but its stuff id rather not do again. This type of work converting to 4wd is no biggy to me.

suit yourself :thumb:

 

[jpowel29]

Adding a front diff to the 2wd frame is pretty straightforward. Need to weld one upper mount on the driver's side and drill one hole through the passenger's side frame rail (the factory indent is already there) so you can press the bushing through. I did buy a complete 4x4 front frame half and had it for reference and to use pieces off of it. Used the spindles. Upper and lower control arms looked identical between the 2wd and 4wd.

Added a manual transfer case and floor shift lever (another factory indent was already in the trans tunnel).

Trans cross member and T-Bar cross member look the same. Only thing I don't know that are the same (because I never checked between 2wd and 4wd) would be the T-Bars and keys.

 

[Wicked Mayhem]

Adding a front diff to the 2wd frame is pretty straightforward. Need to weld one upper mount on the driver's side and drill one hole through the passenger's side frame rail (the factory indent is already there) so you can press the bushing through. I did buy a complete 4x4 front frame half and had it for reference and to use pieces off of it. Used the spindles. Upper and lower control arms looked identical between the 2wd and 4wd.

Added a manual transfer case and floor shift lever (another factory indent was already in the trans tunnel).

Trans cross member and T-Bar cross member look the same. Only thing I don't know that are the same (because I never checked between 2wd and 4wd) would be the T-Bars and keys.

Frames/spindles/suspension are identical, minus the front diff mounts.

That is the only mounting point i had to add BECAUSE im adding a drop crossmember lift kit, which mounts the driver side of the front diff to the new crossmembers. My frame didnt have a factory indent for the hole to drill, and even if it did, you have to weld in a sleeve for the bushing to go into. I knocked the studs out of the pass side mount because the mount cant go in with them because it hits the oil pan. I put 5/8" bolts back in it.

 

[TheBac]

Member Matt78 is also planning this changeover.

 

[PureHybrid]

Watching this one. Debating whether it would be easier to convert to factory 4wd or do a SAS while I'm at it?

 

[Wicked Mayhem]

Just depends on how much work you want to get into and are capable of. I don't have a need for a sas. I don't really have any need for 4wd period. Just something I always wanted if I ever got a 3/4 ton diesel. So I'm making it happen. Plus I don't want the truck any bigger then it is now and I don't think that can happen with a solid axle.

 

[Wicked Mayhem]

Put in the pump rub kit yesterday, and half ass cleaned up the transfer case and front diff. Plan on cleaning them up some more and painting the axle tube today.

 

[PureHybrid]

There are a couple members here that are fairly low on SAS setups. For the price of a front diff and CV axles, you're right at D60 prices. $.02

 

[Wicked Mayhem]

That's good to know for the future.

 

[testdrive]

Nice work, you should be pleased with your conversion.
I changed my Suburban from 2wd to 4wd. The front differential and associated mounts was straight forward.
The electrical was more of a challenge and actually took more time.

 

[Wicked Mayhem]

Yeah that's why I had someone who knew a lot about electrical take care of that. I could have gotten it to work, but be right? Probably not. :rofl: hopefully it's fairly straightforward as far as hooking it up and routing the wiring. I don't even know where the transfer case control module goes LOL

 

[Wicked Mayhem]

Baby steps. All the wiring is ran, and i have what i can hook up, hooked up. Plan on pulling trans next weekend to swap output shaft and tail housing and install tcase finally. After that as long as it all works right all that will be left is to decide on a lift and install that and the front axle.

Pulled front axle all apart, new outer axle bearings and seals, new pinion seal and crush sleeve. Its ready to go.

Just making sure it all fits lol

 

[Wicked Mayhem]

Transfer case install tomorrow. :woott:

 

[Wicked Mayhem]

Well we made a ton of progress yesterday. Pulled the trans out, got it stood up. The output shaft i bought was right, but i never found any info on needing any other trans parts. Well we got it apart and noticed the speed sensor tone wheel is different. That is the 2wd name for that piece. I called a local transmission parts place and he gave me the gm part number for what i needed. Of course the only parts dept that had one in stock was Michigan. So my dad took some dimensions and figured up how thick that spacer needed to be and machined the old one. Checked the end play and it was within spec so we rolled with it. Got all the wiring hooked up and stuck the actuator up where i could see it and it all works. put it in 4lo and man thats weird :rof. Ive never had 4wd so 4lo was like :cookoo[1]:. So everything is good to go. All i need to do is buy my front lift kit and it will be a fully functioning 4wd truck.