megamc

1990 4Runner V6 A340h automatic trans. The transfer case will not drive the front shaft. Is the 4wd engagement all mechanical or is there an electrical switch on the transfer case that engages the front shaft?

4Runner202020

do you have manual hubs...
that might be your issue. lol

megamc

The problem is the transfer case is not turning the front drive shaft. The front axle and hubs work fine.

eric-the-red

I think on the A340H tranny the transfer case is electronically controlled. There is a 4th solenoid that controls it.

n4ynu1010

hehehe , thats something I would do is forget to lock the hubs , my Jimmy is pushbutton on the dash so I'd be like why isn't working ..........

thefallman

Your automatic is the A340H it is manually controlled with a Electronic safety just like the transmission its self. the computer controls the electronic safety to prevent the tranfer case from shifting into or out of 4wd at speeds higher then 35mph. As far as i know, and the wiring diagrams indicate, this actually only applies to 4lo not 4hi. the electronic safety wont let it shift down to 4lo or out of 4lo at speeds greater then 35mph if you disconnect the solenoid on the tranfer case, its right behind the transfer case shifter, you can tell whether this is an ecu issue or a tranfer case issue. Because with the solenoid disconnected it should work as normal.