KZN130 Surf sticks in 4WD

[bronx89]

Hey guys,

1995 KZN130 Hilux Surf 3.0L TD auto.

Have had an issue pop up that is rather annoying. The truck will drive fine in 2WD, it will also go into 4WD (low and high) fine. The issue arises when I try and get the truck OUT of 4WD and back to 2WD. Whenever I try and get out of 4WD the light stays on and trucks seems to stay in 4WD no matter how many times I try - yes I've done the reverse trick and back & forth trick a million times - it just won't come out.

However, I've found that turning the key to the OFF position and then back to ON (whilst the truck stays running due to the turbo timer) the 4WD light will go out and the truck appears to be back in 2WD, if it doesn't work the first time it always works the second.

I have crawled under the truck and the front drive shaft does NOT spin freely (when in 2WD) as it should. I've jacked up one front wheel at a time and they spin freely and do not cause the front drive shaft to spin so the front diff is NOT engaged and the ADD appears to be working correctly. I've jacked up both front wheels at the same time and both spin freely and don't spin the other and also don't spin the drive shaft. I have crawled under the truck and had someone press the 4WD button ON/OFF and I can hear the motor on the transfer case going (although not very loudly). I've replaced the 4WD ECU under the head unit with a mates ones out of an identical truck and the issue remains.

I've posted up on numerous other forums and no one seems to know what's going on. Has anyone on here seen or heard of this front drive shaft/4WD sticking issue before?

I'm not sure if it's something mechanical, electrical or vacuum-related causing the front drive shaft to stay engaged all the time and make the truck stick in 4WD (unless the key is moved to OFF then ON) or if these two issues (drive shaft and sticking in 4WD) are even related!

Someone please help!

Thanks

EDIT: Is the transfer case shifter motor the black circular bit on the top of the transfer case that is attached with what looks like two screws?

[budweiser]

i had similar prob. when i got my 1994 3l. and replace every single vacuum lines and had it sorted.
hope is same with yours (something simple)

[Bazcam]

http://www.hiluxsurf.co.uk/showthread.php?t=66755

[bronx89]

i had similar prob. when i got my 1994 3l. and replace every single vacuum lines and had it sorted.
hope is same with yours (something simple)

What problem did yours have exactly? And what hoses did you replace? The ones going from the VSV's to the front diff actuator? Or transfer case ones, or?

Bazcam: have just read that entire thread, looks good! Is there really no down side to this mod? You can still shift in/out of 4WD whilst on the move and it doesn't strain anything that isn't usually under strain? It's also supposed to fix your 4WD when it won't come out due to ADD issues isn't it? Will it fix my front drive shaft not disengaging too or does this mod leave it constantly engaged like it is now so it can't free-spin whilst stationary?

[NiftyNev]

There's no vacuum hoses on the transfer case. The hose on transfer motor is just a vent hose. If the front tail shaft does not rotate freely when in two wheel drive, then it points to a problem with the transfer motor or the electrics for it.

Nev.

[bronx89]

I was thinking the motor too, but then I read this (from the thread link above to the ADD collar mod on front diff):

"When people have trouble de-selecting 4WD, it's 99.9% of the time due to the vacuum actuator not sliding the collar sufficiently and disconnecting the passenger side driveshaft, due to poor vacuum supply or a faulty/leaking diaphragm/hoses in the actuator on the front diff, which in turn doesn't activate the sensor to tell the electric actuaor on the transfercase to disconnet drive to the front propshaft, so you're stuck in 4WD."

Thoughts?

[NiftyNev]

There's no sensor on the front diff to lock or unlock the front drive shaft. There are switches on the transfer case to operate the VSVs for the ADD not the other way round. There's one sensor and one switch on the front diff. One is oil temperature and the other just operates the light.

If you want to test the ADD seperately there's a Blue and a Brown VSV. To test the front ADD just disconnect each plug and then apply power to the Blue VSV. (Make sure you get the polarity right. The earth is white/black stripe on all of them IIRC.) Front ADD should engage and light will be on. Do the same for the Brown VSV and ADD should disengage and light should be off.

Nev.

[bronx89]

There's no sensor on the front diff to lock or unlock the front drive shaft. There are switches on the transfer case to operate the VSVs for the ADD not the other way round. There's one sensor and one switch on the front diff. One is oil temperature and the other just operates the light.

If you want to test the ADD seperately there's a Blue and a Brown VSV. To test the front ADD just disconnect each plug and then apply power to the Blue VSV. (Make sure you get the polarity right. The earth is white/black stripe on all of them IIRC.) Front ADD should engage and light will be on. Do the same for the Brown VSV and ADD should disengage and light should be off.

Nev.

Oh ok, I've hopefully got a marine electrician mate coming around tonight with all the gear to test the above.

What would be causing the front drive shaft to be constantly engaged then? Do the VSV's or the ADD system somewhere tell the front drive shaft to engage or disengage?

Do you think the 4WD sticking ON (unless the key is turned to OFF then ON) and the front drive shaft being constantly engaged are both a result of the same issue/cause/fault?

Is there anything else I can get my mate to check tonight when he comes around with his electrician gears?

[NiftyNev]

What would be causing the front drive shaft to be constantly engaged then? Do the VSV's or the ADD system somewhere tell the front drive shaft to engage or disengage?

No

Do you think the 4WD sticking ON (unless the key is turned to OFF then ON) and the front drive shaft being constantly engaged are both a result of the same issue/cause/fault?

Could be but I don't know what would cause that. Think I heard of that problem once before but don't remember if a solution was found.

Is there anything else I can get my mate to check tonight when he comes around with his electrician gears?

Yes. When you test the VSVs and the ADD as I described above then test power going to each VSV plug with the plug on each off. The blue VSV plug should have power with button in or in low range 4WD. The brown plug should have power with button out in high range.

If all this is ok then you can go back to the transfer motor. Leave the VSVs unpluged and using the button, check that front tailshaft locks when button in or in low range and that it unlocks with button out in high range.

Is the hose on the transfer motor ok? No splits or has come off? Is there any evidence that water could have gotten into the motor somehow?

Nev.

[bronx89]

Do you know where you heard that problem i.e. was it on a message board?

Will leaving the VSV's unplugged have any effect on the front drive shaft? As it is constantly locked at the moment with everything plugged in as normal in both 2WD and 4WD hi/low.

I have actually had the cap off the transfer case bit before as there was water and sand and mud in there, gave it a good clean out, sanded contacts back and put it back together with sealant (this was when 4WD wasn't working at all). The hose itself I also replaced as it was split. So unless the motors aren't sealed on properly I guess water could have gotten in there too? I do go in fresh water and that part would be submersed.

Ok will check all that stuff when he's round in a few hours.

EDIT: he wasn't able to make it yesterday so hopefully today -can he check the transfer case motor at all while he's at it?

[Red hilux]

I just had a skim read of this post but when you turn 4wd off, did you put the car in reverse and reverse back a few meters??

Mine sometimes doesn't disengage 4wd while stationary but as soon as I reverse you can hear it click off.


Had the same thing happen to a Nissan bogroll on the weekend, reversed and all fixed

[bronx89]

Hi there thanks for the suggestion but that's the first thing I tried. It's definitely a mechanical/electronic/vacuum issue

[Red hilux]

Maybe something worth trying
http://hiluxsurf.co.uk/showthread.php?t=66755

At least it should rule out some parts

[bronx89]

Hey yup have read that post before and was going to do the mod but my transfer case is always locked up so the front drive shaft is always engaged. So this mod wouldn't fix the issue if I understand correctly.

[dessertdog2002]

I have the same issue i think read all the posts on here about it but was wondering If its safe to drive it locally untill i find someone who can look at it tried the reverse suggestion didnt work for me tried the switching off and on no luck there either.Just moved to my area so dont have any local contacts here in Ashford kent.Mine shows all wheels lit up green and the dif light is on on the dash display i just cant get it to go off anyone know a good 4x4 mechanic near me please.
Ok after spending a few hours playing i have now got all 4 wheels and the dif lock now flashing they were all solid before but i still cannot get it into 2 wheel drive.Can i drive it like this safely ?
Any help would be gratefully received.
Well after spending 5 or 6 days playing about its now out of 4 wheel drive but the dash icon is still flashing 4 green wheels and dif lock icon is also flashing anyone got any ideas please.