4WD won't engage

[Badger]

Not sure if this is mech or elec?

I've got a 2.4TD 93 surf. The H4 won't engage on the move (it used to) The 4WD light comes on on the dash and the buzzer sounds when trying to shift on the move. The 4WD engages fine when stationary.

Anyone got ideas?

Thanks
Badger

[surffreak]

what speed are you trying to engage 4wd at ?
on mine i have found that it needs to not be pulling (back off the revs)to allow it to disengage it might be the same for engaging?
i have not tried to engage while on the fly so cant help more than that.
Only that it might be the vacuum not strong enough .

[TonyN]

**copied from old forum (cos its to long to type out again)..............**

We've had the soloniod (on the end of the Transfer case) go sticky on trucks here before, verify its getting 12volts then pull it and check its free to move in and out.

You also need to check all the pipes and wires to the ADD system (on the pass side of the front axle.

Is the 4WD light on the dash coming on? Also it won't work unless the car is moving.

E-mail i got from an ozzie mate last time someone asked this......

"Another thing to look at is the servo on the back of the transfer that engages 4wd sometimes sticks .If he gets stuck you can actually pull the servo off and engage the transfer manually.From memory only 4 10mm bolts hold it on."

There is also a relay under the dash.....


"it wont be inguaging 4x4, they always do it but i cant remember how you fix it, but i do know it has something to do with a reverse pattern relay under the dash.

i know there are 2 different types, one the current flows AC and the other DC and the solenoids always pack it up not allowing the current to activate 4x4.

In an auto it operates of the "lock" that starts the car when it is N or P, you know that safety switch on the gear lever, hense the reason on shift on the fly as the truck must be stopped to put into 4x4.

On a manual, i have no idea why, but im not 100% sure, but i think it is in the same loom as the as the instrumention and works off the speed sensor."

You should still be checking the ADD pipes and connections on the front diff as well, the light won't come on untill the solonid on the t/case is engauged and the ADD acuator has moved.

Could be the above relays if power is intermitant.

[Badger]

what speed are you trying to engage 4wd at ?
on mine i have found that it needs to not be pulling (back off the revs)to allow it to disengage it might be the same for engaging?
i have not tried to engage while on the fly so cant help more than that.
Only that it might be the vacuum not strong enough .

Trying to engage at low speed 10-20mph. Thanks all for the info. I'll tackle it this weekend.