Another 2wd to 4wd conversion 06 DC

First of all I'd like to thank mrdirtjumper for their thread on the whole process, without it I don't think I could have done it. And of course the Toyota FSM for being so detailed.

Anyway, it was a long term goal of mine with this truck to be able to do some offroading and maybe rock crawling so I set my sights on a 4wd conversion. The process took five days for me personally, about 8 hours a day but someone more skilled than I could do it in probably just a weekend. For some background info I just started working on cars last year after paying mechanics my whole life. No lift although it would be nice, jack stands are all you need for this.

I don't have a ton of pictures but I do have some. I'll outline a pretty vague process of how I approached it for anyone curious.


Step 1: 4wd engine harness, 4wd bezel, and 4wd ECU.

• I wanted to do this first because I knew the 4wd harness would work with my rwd one, and I wanted to be positive it would work before doing everything then having to scour for a new one as well as reinstall it. Bezel and ECU are plug and play.

Step 2: Drop l&r exhaust pipe, remove rear driveshaft and skid plate.

• Pretty straight forward (if you don't live in the rust belt I guess), definitely want to soak the bolts/nuts in rust penetrant beforehand. I was lucky enough to not need a torch but I did snap two studs on the exhaust. Just follow FSM procedures for this and the driveshaft. Only thing I'd say is try to only use hand tools on the exhaust hardware, at least mine was super brittle.

Step 3: Pull A750e and install A750f and transfer case, don't forget new trans mount too.

• I did this before the front diff on the recommendation of mrdirtjumper. Was the first transmission I pulled/installed. Honestly not too bad but you definitely want a dedicated transmission jack. Not sure how you would do it without it. Transfer case has to go in at an odd angle the jack doesn't like (or rather gravity doesn't like) your only option here is to pick it up and lift it onto the extension housing (if you didn't install it to the transmission in the first place like me anyway).
  

Step 4: Install front diff, then swap knuckles for 4wd ones, then CV axles can go in. Lastly do the front driveshaft.

• Front diff was harder than I expected to get in. Maybe a skill issue. Had tremendous difficulty with the rear mount, for some reason the stud spins on my brand new one around the nut. Can't find a place to hold the stud, as it's recessed so I've just accepted it for now .Definitely do new OEM upper ball joints with the 4wd knuckles. Currently on TRQ cv axles and will spring for OEM when they inevitably shit the bed. I noticed a little too late that my front diff has some dirt compacted on the inside. I wish I tore it apart and cleaned it but it was already in and I didn't really want to pull.it again. Hoping a few drain and fills will get the debris out. Part was from an AZ junkyard.
  

Step 5: Install new 3rd member, then rear drive shaft.

• Easiest part of the job for me. Drive shaft didn't have match marks (thanks scrapyard) so I just kind of put it together in a way that made sense and it works good so far, little to no vibration introduced. I got the rear diff built by ECGS, because my previous rwd one didn't have a gear ratio that matched the front diff (of 3.91). New rear diff has a locker that I'm excited to try.

Step 6: Fill everything with fluid, reinstall exhaust and skid plate.

• Opted for Lucas dino juice in the diffs/t case and Valvoline max life ATF instead of WS after speaking to a few people at a transmission shop. Was way cheaper than WS too. Sadly one of my studs is kaput and will need replacing. Currently right hand exhaust pipe is held up by 2 nuts instead of 3, but no exhaust leak yet. Will definitely fix soon.
  

Step 7: Pray your junkyard parts all work and turn the key.

First test drive I was met with a grinding noise. Was really hoping it was the dust shield, bent and rubbing onto the rotor. Fortunately it was in fact the bent dust shield rubbing on the rotor. Fixed that and now it runs like a top. Ready to hit the trails!

 

//clapping, foot stomping sounds//

 

I've been wondering. I sometimes see low milage 2wd tundras really cheap on FB. They go for about 1/3rd the price of a 4wd here...keep thinking even if it doubled the price to convert one, it would still be a bargain.

 

If I had to do it again I would try to get a nice(ish) roller off copart instead of buying piece by piece. Think that would have been cheaper.


I did have a question for members of this forum, does anyone know where the thin breather hose from the front diff is supposed to plug into? Currently it's doing a good job of dangling above my driver CV axle.

 

They normally sit just inside the framerail. Lemme see if I can grab a pic.

 

I saw the plugged one resides below the brake booster in some picture but it looks like the smaller one should be plugged into... something. Somewhere. I'm yet to find that somewhere.

 

Here you go: https://www.tundras.com/threads/2005-tunda-dc-4x4.158687/

Note the two bumps above the big ass yellow dipstick in the 1st reply. That's where the breathers sit.

 

So how long did it take overall in wrench time? Hour, hour and a half-ish?

 

You're on the right track, most of the time spent is trying to finagle things into position and just removing parts. Tightening fasteners is the break from all that.

 

Excellent work and thanks for documenting it here.

 

There's a technique to removing/installing the front diff. I can't remember off hand because it's been a year or two, but after many attempts i was able to remove the front diff in just a couple minutes, set it on the ground, then bolt it back into place in about 3 more minutes...maybe it was even less time than that? It did take me a while to finally figure out that procedure though.

 

Definitely. I was fumbling with it for longer than I'd like to admit before something just clicked and it magically fit. It all feels like a fever dream now. I'll have to pull it at some point to most likely install a new rear mount unless I can somehow find a way to get the stud to stop spinning on the nut.

 

Thank you. That solves the problem of the thicker one with a plug. However I am still unsure where the thinner one plugs into. Any ideas? It originates from the front diff. Pics attached.

 

Not sure on that, can't tell what it is, but it shouldn't be sitting on the CV axle like that. In the 1st pics, is it plugging into the actuator? I can't tell what the round cap is that it's touching.