Prerunner to 4X4 conversion, concluded

After lot of reading, understanding how the different Toyota 4X4 transfer cases work, estimated costs around $2,500 and the most important, learning from others 4x4 conversion experiences, I'm finally in the boat of Prerunner to 4X4 Conversion.
For this project I'm using a 2006 Toyota 4Runner transmission, mainly because in my country I could'nt find a used FJ nor a Tacoma transmission. This way made things a little complicated cause I had to figure out how all electronics match to my 05 Toyota Tacoma SR5 Prerunner.

 

Here a list of all successful conversions I've been able to read and ask pioneers about their experiences doing this job. They have inspired me to do go on with the conversion.

http://www.tacomaworld.com/forum/2nd-gen-builds/233527-first-2nd-gen-2wd-4wd-ifs-conversion.html

http://www.tacomaworld.com/forum/2nd-gen-builds/285377-vancity4x-prerunner-convert-build.html

http://www.tacomaworld.com/forum/2nd-gen-tacomas/311339-lucky-07-prerunner-4x4-conversion.html

https://www.tacomaworld.com/threads/1st-oem-2wd-4wd-convert.324645/

https://www.tacomaworld.com/threads/evolution-of-the-taco-2x-two-4-wheel-drive.448441/

 

My first attempt to design a relay base wire harness, I desisted because the cost and the space for 12+ relays + added fuses were a not feaseable way, however the exercise help me to understand how the system should work.

https://www.tacomaworld.com/threads...rcuit-for-prerunner-to-4x4-conversion.368805/

 

Subbed, i want to tackle this as well. Are you using a tcase from the 4runner as well or FJ?

How about the front diff?

 

I'm using the 4Runner transfer case, front differential and 4WD ECU.

 

This is how I have figure out 4WD ECU connections to my prerunner. Comments, suggestions will be appreciated.

Image edited.

 

Pic 1: 2006 4Runner engine-transmission wire harness, I thought of using it as a whole, but colors on some wires are different from actuall wire harness, this could be troublesome in the future. I decided just to take apart necessary parts (red dots on previous diagram).

Pic 2: 2006 4Runner transmission with transfer case and actuators.

 

Im wanting to do this on my truck and im still in the research and pricing phase, good luck to you, ill be following your progress

 

Cleaning front carrier.

 

sub'd

 

Well, I just finished one side of the wire harness (F9 connector) for the 4WD ECU. I tested it, but by now I only get 4WD and 4LO lights blinking. I guess 4WD ECU is waiting for the input signals of transfer case and front carrier actuactors.

I used connectors I had on hand. Weld cables and insulate them.

Then I connected everything as per modified 4Runner wiring diagram.

 

Today I have tested the complete wire harness hooked to 4WD ECU, front carrier and transfer case with very positive results. Everything works as it should. I will update wire diagram since tacoma prerunner is not wired for all of the 4x4 connections. (these are connection to skid control ecu and engine ecu). Any way, even if I build every connection, is is very likely that those ECUs are not programmed to take any action if any input is given.

 

I have a nice video showing the test process, but I can't upload it, so I did a GIF image. Not to nice but it gives an idea.

 

Thanks to @AaronArf for his contribution with this project.

 

While waiting for pending parts, I started to modify transfer case cross member.., I took detail measurements before beginning with modifications.
Center cross member hole is 15 3/16" left to rigth.
Cross member has to be modified so that it seats 1" down, and center transfer case support 15/16" forward.

 

Parts are arriving, just need axle shafts to arrive to begin conversion.

 

Very cool

 

Meanwhile..

 

Must problems I know about, are more related to lift causing trouble with 4x4 system than 4x4 system itself. Perhaps my dad has a 4x4 with only same problems prerunners have.