Sticky Surf 4WD?

[bronx89]

Hi guys,

Right, I've got a 1995 Hilux Surf KZN130 1KZ-TE Automatic. Everything was working fine until a couple of weeks ago the 4wd decided not to engage (low or high). Ended up taking a little cover off the transfer case and draining muddy guck out of it, sealing it and sanding back the contacts that contact a gear in there. Also replaced a cracked vacuum hose on transfer case. Everything worked fine after that for a few days until now.

Now, it will go into 4wd (low or high) every time as normal, BUT it won't get OUT of 4wd (the light stays on and I can hear it is still in 4wd) UNLESS the truck is turned off and then back on and it will instantly be out of 4wd. I also figured out the other day that the truck doesn't necessarily have to be turned off. I have a turbo timer and found out that when the truck is stuck in 4wd (low or high) I can slow to a crawl, turn the key to ACC (truck stays running as the turbo timer is on), then press the 4wd button to off (if in high) or move the shifter to high (if in low), then turn the key back to ON and the 4wd will be instantly disengaged (no light).

This means it is electrical, right? Not vacuum if going from ON to ACC back to ON (with the truck constantly on) will disengage the 4wd system and turn the 4wd light off? Relay? I can hear the relay in the 4wd ECU behind the stereo clicking away so don't think it's that one.

Anyone experienced this before or have any idea what it would be!?

PLEASE HELP! NO ONE HAS BEEN ABLE TO HELP ME!

[Koi]

So is all this in and out of 4wd being done on the move? how fast?
Try it when vehicle stationary and if it doesn't come out of 4wd try reversing a little bit see if it releases then.

[bronx89]

I always shift from high to low or low to high at a complete stop in N or P. Shifting from 4 high to rwd I do it both on the move (up to 30-40km/h) and at a complete stop.

With this issue that has popped up I've tried getting it out of 4wd moving, stopped, reversing on soft stuff for a good distance, everything. Nothing gets it out except turning the key to either OFF or ACC and then back to ON - this gets it out of 4wd instantly and works whether the truck doesn't turn off (due to turbo timer) or does turn off.

Idea's?

[bronx89]

Anybody?

[Koi]

Also look at your ADD vac lines they are on the driverside of the engine bay your 4wd works on vacuum . if they are ok check the vac tank which is under your driver side wheel arch you might have a leak if that is ok the chances are the solenoid on the diff is either stuck or the wiring to the solenoid has come off or broken.

[bronx89]

Also look at your ADD vac lines they are on the driverside of the engine bay your 4wd works on vacuum . if they are ok check the vac tank which is under your driver side wheel arch you might have a leak if that is ok the chances are the solenoid on the diff is either stuck or the wiring to the solenoid has come off or broken.

I've tried looking for that ADD system and the vac lines on the drivers side under the hood but can't find them/don't know what I'm looking for. Is it the real small box type things with a couple of vac lines going to them? Look like relays?

The the vac tank, what do you mean under the wheel arch? Is it in the engine bay towards the bottom beside the wheel arch? The only thing under my wheel arch is my wheel

Also where abouts is that solenoid on the diff for me to check? And is there only one?

All of the above 3 things, is any of these were the culprit, would the truck still be able to get out of 4WD by simply being turned off then on (not the engine just the key/ignition)? Because if not, then it won't/can't be any of them.

[NiftyNev]

When in 4WD the front tail shaft will not be able to be turned by hand. When in 2WD it will. Just check the tail shaft when in 2WD. If it's still locked then your problem will be with the shift motor. Take it out clean it up properly or replace it. BTW there's no vacuum to the shift motor. The hose is simply a vent hose.

Nev.