The way I did it was to put the truck on jackstands so all wheels were of the ground. And then put it in 4wd and see if all wheels spin.

 

Or if you have locking front hubs Jack the back tires of the ground, unlock the hubs, put it in 4wd and have someone see if the front axle spins when you give it gas.

 

cool thanks for the info will work on it this weekend gotta fix rear drum this weekend anyway my slave cylinder is leaking

 

I am new to four wheel drives, but the first 4runner I looked at buying, on the test drive I put it into 4wd and you could feel it really when you turned the truck on pavment. The main question I had was is there a fuse for the 4wd or something that will stop sending electric power to the 4wd system? It is acting just like the 91 that I mentioned with no battery.

 

And I also today ran a vacum line down to engauge the ADD and the 4x4 light came on and the front axle was locked in but nothing. The big thing is the shifter won't stay locked in 4L it slips up into the 4H spot. Is there a fuse for the 4x4 system?

 

if its slippin out of 4lo no fuse is going keep it in 4lo what you need to check is the shifter in the cab and on the xcase if its an automatic there are 4 screws to pull the cover and pop the ect button out and look at the 4wd shifter mine was kinda the same way i just cleaned it up and moved the little pieces of plastic to where it would go all the way back and i sprayed the xcase shifter on the case with some engine degreaser and wd40 and it worked awesome. if that doesnt solve the problem then it could be a problem in the xcase and the first thing i would do is drain it and see what the fluid looks like

 

If you look at the link I posted in post #8 there is a diagram on page one that shows a fuse for the system, where that fuse is at I dont know. I tried looking for a fuse when I had my problem and had no luck, but i didnt look to hard.

 

Yea that's what I say and I am trying to find were that fuse is located.

 

i would think the fuse would be in the kick panel in the truck

 

I looked it's not there.

 

Yeah i tried looking in the owners manual and fuse box diagram, also tried searching, but no luck. But as fireman was saying, I dont think its an electrical problem if its not staying in gear. Since the light comes on the electrical part of it should be fine, especially if its going into 4hi. Hopefully someone with better knowledge takes a look at the thread, i dont know enough to really help you out.

 

The only time the light came on was when I ran a vacum line down to the Front axle. But when I just shift it into 4H nothing happens no light no going into 4wd nothing.

 

it cant be an electrical problem considering the only electric thing that makes the 4x4 system work is the solienoid that operates the vsv. so it has to mechanical

 

What's the vsv?

 

then that means the problem has to be back futher so the front end is fine and the sensor in the diff aucator is fine that means that eitehr the vaccum is getting through the vsv or there is a leak somewhere in the vaccum lines. so the cab is fine and the electrail part is good and so is the front axle so that narrows it done to the under hood part check the vsv and all the lines

 

the vsv is what send the vaccum to lock or unlock the 4wd

 

Isn't that the ADD?

 

no add means automatic disconnecting differental the vsv is the controler and a part of the ADD system without it there would be no ADD system

 

In your first post you said you were getting vacuum at the solenoids, so the only thing between those and the actuator is two vacuum lines. There might be a leak in one of the two lines running from the solenoids to the actuator, try seeing if you have vacuum in the lines where they connect to the actuator. That is where my problem was so you can reference the picture I posted. Luckily mine was just loose, but it would be easy to replace one of those hoses if that is your problem.

 

Were is the vsv located at?