1993hiluxsr5

first off, i apologise if i have missed a thread that already covers this issue but i need help

i have a 1993 hilux sr5 with independant front suspension and an air lock front diff.
the problem is i can not get the car out of 4wd, and the light on the dash is always on no matter what i do.
When i click the 4wd button i hear a motor go, then when i unclick it i hear it again, i also hear the motor when i put it into low range.
but it still never gets out of 4wd, the light never goes out.
the car also jumps the front wheels and skids the inside tire when im on hard lock and has a loud knocking noise from the diffs (not sure which one), eg trying to park.
and im guessing this is because the 4wd is on and the diff lock, but i cannot get the car out of 4wd.

i and mechanically minded and have lots of tools so i am able to try and fix the problem myself but i have no idea where to start.

any help will be appreciated.
Thanks

hilandfrog

Hearing the motors may mean they are working correctly... yet it is not known if the vacuum hoses are attached to both motor and axle?

Could be totally different, but my tundra had a hose off the front, it is my belief that that hose is what allowed me to use 4wd again....

I love manual hubs, they seem much more positive.

Repo

75k5toy

Try put in reverse and give it a few pulls, sometimes that works.

1993hiluxsr5

thanks for the quick replys guys, hilandfrog i have 2 hoses coming from my front diff, and they attatch to what looks like another motor, and the only motor noise i hear when the button is pressed it the one on the transfer case, does this mean the front motor is the problem ?

and 75k5toy, do i literally just drive it in revers in 2wd ?

another thing is my hilux will not roll backwards, even with both gearbox's in neutral, i even tried it on a hill and i still couldnt push it backwards, whats wrong with it :S and yes the handbrake was off

hilandfrog

I'd love to help but I have no clue....

Perhaps someone w/ some skillz/ photos will help

Repo

iamsuperbleeder

wait wait wait... are you saying that you have an ARB Air Locker, or are you reffering to "air lock" as the mechanism that actuates the 4WD for the ADD system...

a4runnerfreak

Thats what I 1st thought....but I'm thinking he has the ADD system, and thats what he is referring to an "air lock".....

iamsuperbleeder

that's what I'm under the assumption of too, but I just wanted to clarify

1993hiluxsr5

hey, yes sorry i think it is an air actuator and add system. sorry for the confusion

1993hiluxsr5

ok update, i have check the air lines and they seem to all hold there vacume perfectly, and i have also tried the reversing trick, but with no joy, its still locked in 4wd
i am starting to think that it may be an electrical fault with the ADD but i dont know what it could be, all the wires are attached as far as i can see.

i have a thought though, the ADD indicator switch on the front of the diff is very mucky, and iv seen the wireing diagram for the ADD and this indicatior is linked to the relay and switch, so im thinking that this might be either faulty or broken, what do you guys think ? could this cause it not to work ?

ilostmypants

have you tried crawling under and just un-doing the airlines and seeing if it disconnects?
then putting some caps on it, that way you wont frag your front diff in the mean time while your still driving the truck.

is it a arb locker?
is this a normal hilux/pickup? or an Asian model hilux aka not the north American model?

1993hiluxsr5

im not really sure which airlines to disconnect, and its a air actuator that locks the front so i dont think its an arb locker.
and i dont know if its asian or american, how do i tell ?
thanks

1993hiluxsr5

Ok, so were making progress, the front diff works and is ok, however i did have to dissengage the diff lock manually, which involved disconnecting the vaccume pipe, removing the 4WD sensor and pushing the sensor arm back manually. The front diff is completely dissengaged now so i can drive it safely.

After checking the A.D.D solenoids one appaers to have a constant 12v running through it whilst the other has 0v, even when switching between 4WD and 2WD which would lead me to beleive that the A.D.D. relay has gone, thanks for everyone's help so far, i will keep you posted about the relay and let you know if i get it fixed!

1993hiluxsr5

UPDATE: Ok so the relay works, the solenoids work, the button works....... yet it was still stuck in 4wd, the solenoids would simply not switch over, eventually i got annoyed and created my own relay circuit with a switch on the dashboard, now everything works perfectly, now i can switch between 2WD and 4WD with diff lock anytime, i have no idea what is wrong but now that it works im not really fussed! Thanks everyone for your help, if anyone is having a similair problem contact me and i can let you know what i did in detail to fix it