Dmax 4x4 stuck in hi and low and cant get into 2 wheel drive

[mattyboy]

Ive just had my isuzu dmax 2016 plate converted to a tipper and when i went to pick it up a major fault has developed and I cannot get out of 4 wheel drive. The circle electronic dial changes between 4 low and 4 high fine but when i turn it to 2 wheel drive it whirs and you can hear it trying to change to 2 wheel drive but it doesnts. It whirs again and on the dash it changes to 4 low drive. This is doing my head in, is this something that anyone knows anything about? Could it be something to do with the earth from the tipper ram of the alterations in wiring that have gone on to the rear lights with the tipper body being put on? Or has it somehow got stuck as its been sat for a month and a half???

[Ratman]

Does the tipper unit run off a pto bolted to the gearbox or is it on a separate battery/pump setup like on a tipping trailer set up?
If its off the gearbox then it could be related to that, electronically/mechanically..... just a punt, i’m no expert ?‍♂️

[mattyboy]

10 minutes ago, Ratman said:

Does the tipper unit run off a pto bolted to the gearbox or is it on a separate battery/pump setup like on a tipping trailer set up?
If its off the gearbox then it could be related to that, electronically/mechanically..... just a punt, i’m no expert ?‍♂️

the pump is powered from the car battery

[Will C]

Try jolting the throttle on the move (slowly) between 4h and 2h or reversing while switching to 2wd. Some times they stick if it’s been working hard in 4wd

[ESS]

We had a similar problem with a Ranger. There was a solenoid underneath on either gearbox or bell housing. Tapped it lightly whilst someone activated switch. Seemed to work.

 

[mattyboy]

thanks for the suggestions both, ive tried these extensively now and cannot get it to shift into 2 wheel drive, i think it may need the transfer box/solenoid that switches between 4l/4h/2h fiddling with or new one potentially?

[Craig.]

Try jacking a front wheel off the ground, to let the transmission unwind? Or both a front and back wheel up, with the hand brake off, other wheels chocked (be carefull). 

[Stubby]

Try switching on a greasy surface so wheels are not so grippy . Might be just wound up a bit .

[ESS]

1 hour ago, mattyboy said:

thanks for the suggestions both, ive tried these extensively now and cannot get it to shift into 2 wheel drive, i think it may need the transfer box/solenoid that switches between 4l/4h/2h fiddling with or new one potentially?

Thats the solenoid we tapped on the Ranger.  On an earlier model we had to put it in reverse and let the clutch out sharply to get 4wd to disengage.

[Wonky]

Its common  when someone has been on hard ground and been turning.. as others say. Get on soft ground  (grass) and try. 
on my old pajero, for 4wd to 2wd  high ratio, I had to decelerate and accelerate hard on hard ground. But it would not work unless going straight..