Bad 4WD VSV's/possible bad switch?

[ToyoLex]

Hey all,

Just picked up a 97 4Runner SR5 with a 4wd system that is not working. Thanks to "Thedurk" I was able to do some preliminary testing by following his suggestions.
What I found how was that there is vacuum going to the upper ports on both VSV's. However, there is no vacuum coming out of the bottom port of either VSV. Regardless if I put the truck in four-wheel-drive or 2WD.

I also checked the voltage on the harness side for each VSV and I got 12-13v in either 2wd or 4wd on the left brown VSV. The right side blue VSV did not have a constant voltage and it jumped all over the place with the shifter in 2wd or 4wd.

When I put vacuum to the one line going down to the add actuator and put the truck in 4wd, it shifts into 4wd and hops around a turn. The light with the 4 wheels on the dash also lights up. I can also switch it back to 2wd while driving and the light goes out and it doesn't hop around the turn.

The problem is the front shaft stays locked all the time until I give the other side of the add actuator vacuum. Then the front driveshaft spins freely.

I just ordered two vsv's as this is one issue. Could I also have a bad selector switch on the trans? Should I hear a relay click if the switch is good?

Any help is appreciated. Thanks

 

[auburnslim]

did you ever figure it out? Mine is making a whistling sound when I try to engage 4wd. It eventually engages, but takes longer than it used to and I have to put in park, or reverse, or neutral or just keep trying gears until it engages now

 

[RPS99SHO]

did you ever figure it out? Mine is making a whistling sound when I try to engage 4wd. It eventually engages, but takes longer than it used to and I have to put in park, or reverse, or neutral or just keep trying gears until it engages now

Replace your TC fluid. Seriously. I chased this issue for many days. All was fixed immediately after changing out that fluid.

 

[auburnslim]

Replace your TC fluid. Seriously. I chased this issue for many days. All was fixed immediately after changing out that fluid.

hmmm, ok, unfortunately some bad weather came in and I couldn't get around to it. I'm going to pull it into my buddy's garage this weekend and try to figure it out. So yours was making a whistle/whining sound too? I am flirting with idea of Aussie locker in the front so maybe this is a sign to go ahead and do that!

 

[feta]

i had a vsv die, i put it up on 4 jack stands, checked voltages and non-vac switching...ect. it was the one of that didn't switch vac obviously. got a 99 avalon one from ebay for 10 bucks or something, search 'toyota vacuum switch' and find one that looks the same around the same years.

It was a while ago, but if I remember correctly, you can use the other one to actuate it in 4wd if you stick the hoses on the proper way. and another way to unlock it.

 

[RPS99SHO]

hmmm, ok, unfortunately some bad weather came in and I couldn't get around to it. I'm going to pull it into my buddy's garage this weekend and try to figure it out. So yours was making a whistle/whining sound too? I am flirting with idea of Aussie locker in the front so maybe this is a sign to go ahead and do that!

No whistling. My 4wd lights were flashing and was getting no engagement when ordered by the 4wd button.