Won't engage 4WD on the move?

[Dodge]

Hi guys,

Ok, I've spent a lot of time searching but not found anything to help, plenty about 4WD not working at all, anyway . . .

My truck won't engage 4WD from the button when on the move, I've tried all speeds even dropping into neutral and second but all that happens is I get the intermittent beep and the dash light flashes.

It slips into 4WD when I'm stopped and in gear as long as the wheels aren't moving, and it will disengage whilst on the move if I depress the button and lift off.

Cheers for any help.

[TonyN]

Not really any good reason why it won't shift on the fly but only when stopped, apart from wear somewhere in the front axle or T/case.

The difference between the shift on the fly ADD stuff and a normal pickup is the sliding collar on the front axle, this lets the T/case sort itself out before drive is connected to the wheels. Maybe the sliding collar isn't properly releasing or the shafts are dragging on each other, this would spin the front prop meaning the T/case won't line up its gears properly till you stop, then go again.

But don't know for sure.

Maybe there are some fault codes for the 4WD system, but ive never seen any. Normally you don't get a light at all till its engaged. I've never seen a flashing light, that sounds like a fault light, unless its just flashing cos its slipping in and out of 4wd quickly wheile not engaging properly.

[Smego2]

try spipping it into netraul and back again, works on mine if the flashy light won't reset.

[TonyN]

You have a 3rd gen, you're supposed to have a flashing light till it engages. (or not, as yours does sometimes... lol )

Us lowly 2nd gen owners don't get a light till it actually selects, till then we're in the dark...

[Dodge]

Not really any good reason why it won't shift on the fly but only when stopped, apart from wear somewhere in the front axle or T/case.

The difference between the shift on the fly ADD stuff and a normal pickup is the sliding collar on the front axle, this lets the T/case sort itself out before drive is connected to the wheels. Maybe the sliding collar isn't properly releasing or the shafts are dragging on each other, this would spin the front prop meaning the T/case won't line up its gears properly till you stop, then go again.

But don't know for sure.

Maybe there are some fault codes for the 4WD system, but ive never seen any. Normally you don't get a light at all till its engaged. I've never seen a flashing light, that sounds like a fault light, unless its just flashing cos its slipping in and out of 4wd quickly wheile not engaging properly.

I get a solid 4WD light on the dash when it has engaged, if I try to engage on the move it just flashes and beeps constantly.

This sliding collar, is it external, could I get to it from underneath without stripping the diff/axle?

try spipping it into netraul and back again, works on mine if the flashy light won't reset.

Tried that, tried every gear and speed and neutral, accelerating, decelerating, coasting. I need to come to a complete stop, I've driven for miles on the snow hoping it will get fed up and just slip in.

This hasn't been a concern before, everytime I've been off road I just stop and engage then carry on, but going from tarmac to ice/snow I'd rather switch to 4WD without coming to a complete stop.

It's a bummer I was hoping someone would have come across this before and there was a simple fix.

[darkdezigns]

i had same prob last febuary,only would engage when stopped.i found after a fair few goes it gave in and worked on the move

[BUSHWHACKER]

It's more than likely a vacuum fault. Either the supply to the actuator on the diff or one of the VSvs on the inner wing next to the fuse box.

[Dodge]

i had same prob last febuary,only would engage when stopped.i found after a fair few goes it gave in and worked on the move

Ah, good plan, wear the bugger down. I'll keep persevering. Thanks.

[Dodge]

It's more than likely a vacuum fault. Either the supply to the actuator on the diff or one of the VSvs on the inner wing next to the fuse box.

Where abouts on the diff is it, can I see it from underneath?

I'll check my pipes. Thanks.

[BUSHWHACKER]

Where abouts on the diff is it, can I see it from underneath?

I'll check my pipes. Thanks.

I removed my vacuum lines, slips into 4wd easily and instantly now.
All explained here....(there's a link explain a bit more too)
http://www.hiluxsurf.co.uk/forums/sh...&postcount=116

[lord lucan]

I get a solid 4WD light on the dash when it has engaged, if I try to engage on the move it just flashes and beeps constantly.

This sliding collar, is it external, could I get to it from underneath without stripping the diff/axle?

Tried that, tried every gear and speed and neutral, accelerating, decelerating, coasting. I need to come to a complete stop, I've driven for miles on the snow hoping it will get fed up and just slip in.

This hasn't been a concern before, everytime I've been off road I just stop and engage then carry on, but going from tarmac to ice/snow I'd rather switch to 4WD without coming to a complete stop.

It's a bummer I was hoping someone would have come across this before and there was a simple fix.

its not a big job to strip clean and lube the actuator, front of the ifs the cover with the 2 vac pipes going to it , there isnt going to be any springs or bits falling out its a pretty easy set up once its of you will see how it works good luck

[BigBobE]

I removed my vacuum lines, slips into 4wd easily and instantly now.
All explained here....(there's a link explain a bit more too)
http://www.hiluxsurf.co.uk/forums/sh...&postcount=116

hey vince, do you have Free Wheelie Hubs on, or how do you engage 4wd since removing vacuum lines???

[BUSHWHACKER]

hey vince, do you have Free Wheelie Hubs on, or how do you engage 4wd since removing vacuum lines???

Not fitted the hubs on mine yet,.

Selecting 4wd is the same as before, shift 'on the fly' or via the transfer stick.

[Dodge]

I removed my vacuum lines, slips into 4wd easily and instantly now.
All explained here....(there's a link explain a bit more too)
http://www.hiluxsurf.co.uk/forums/sh...&postcount=116

That's interesting, thank you.

its not a big job to strip clean and lube the actuator, front of the ifs the cover with the 2 vac pipes going to it , there isnt going to be any springs or bits falling out its a pretty easy set up once its of you will see how it works good luck

I'll have a look thanks.

[BigBobE]

Not fitted the hubs on mine yet,.

Selecting 4wd is the same as before, shift 'on the fly' or via the transfer stick.

cool, just excuse my ignorance once more, why have they this setup included, would they not just leave it out if it works better....