97 4runner 4wd wont disengage

[etcetera]

I have been battling this for three weeks with little help from other forums.

First off, my truck is a 97 T4R Limited w/ 4wd button.

I can engage 4wd (4H and 4L) instantly using the button, however, I can not disengage 4wd to go into 2wd unless I switch the vacuum lines on the VSV or turn the truck off.

So far, I have:

* Visually checked all the vacuum lines.
* Removed and checked the neutral position switch, 4L position switch and 4wd sensor on the transfer case.
* Checked the TC actuator using an ohm meter. 185ohms. I tried to check #2/#3 and the body, but I couldnt get a reading.
* Replaced the ADD switch on the front diff.
* Hot wired the VSVs and they click.
* Hot wired the actuator on the TC and it moves back and forth.

Also, my propeller turns in 2wd.

Thanks in advance

 

[jrock24]

https://forum.ih8mud.com/95-gen-toyota-trucks/266378-2001-4runner-4wd-wont-disengage-fixed.html
Check out this thread.

 

[etcetera]

thank you

But I replaced that switch already

 

[97kurt]

I have the same truck as you but had the opposite problem. Could not get into 4wd at all. Truck did this to me last year and then magically started working, then started doing it again when I went to test 4wd last week.

I ended up getting a $29 vacuum pump at harbor freight and attaching it to the actuator. After pumping it to 25hg on both sides everything magically started working.

By now, I am sure you have seen the FSM test procedure for the vacuum actuated diff. If not here it is.

So if I read your post correctly. It engages fine, but only dis-engages when you swap the vacuum lines at the diff. So that would mean to me that either the solenoid for the release is defective, or the line coming off the solenoid to the actuator has a leak.

If you get a vacuum pump it should be pretty easy to diagnose the leaking line theory. You could also get a length of new line and run it from the solenoid to the actuator. If the line checks out, I'd hit up toyota for a new solenoid or find a junkyard and grab one.