FJ80 Transfer Case Wiring & Engagement - help a Noob!

[jONAH96]

Hello People, I’m in need of help that I haven’t been able to search out on my own. It is to do with the FJ80 transfer case engagement.

Can anyone explain to me simply, can I get an FJ80 transfer case to engage manually like the older FJ40 ones? Or how the FJ80 one is supposed to work?

You see I’m in the midst of a FJ40/FJ80 frame swap and the builder I went with, decided to use the 80 transfer case for the project. I, and the NEW builder (it’s best not to ask…) are totally unfamiliar with this unit and are wondering how we get this thing working. I have a little box with a 4x4 light on it for when it’s engaged and that’s all that I received when I got the project back from the first builder.

Can somebody please school a noob on this? Like as to what I’m in need of for wiring, or ecu’s, to get this thing working.

If there is any other info that I can offer, to add please let me know; I’m just so frustrated at the moment. It has a 2.8 Duramax, 6L50 transmission, NWFab black box and the rebuilt FJ80 transfer case I believe as the powertrain.

Thank you so much for your time and information.

 

[voodu3]

The tab circled on your pic is where the shifter linkage connects and that’s how you shift the transfer case. I’m guessing the black box with 4x4 is a center diff lock switch that locks the diff and allows you to run it in H or L range.

 

[Malleus]

@jONAH96
Good choice, IMHO, but it'd be beneficial for you to download a serivce manual and EWD from the Resources section, for the 80 series. The transfer cases are all the same. I'd recommend the 1995 version, it's very well bookmarked, as I use it daily.

You can remove the viscous coupling from the transfer case, if you wish; it probably won't do you any good for your build. It was put there to make the 80 series, which was Toyota's luxury model when it was new, more pleasant to drive on the road.

The 80 series transfer case circuit has the option for locking the center differential in either high or low range. By default it only locks in low range. Search IH8MUD for "80 series pin 7 mod"; you'll find info there. You'll need the EWD to make this work for your installation, because you won't have the rest of the wiring harness to use. You won't be able to McGyver your case the same way the pin 7 mod is done in the 80 series, but reading up on it, with the EWD, will give you the basics you need to understand what's going on.

Good luck! Looks like a fun build.