Thread: Holden Jackaroo Auto transmission engaging 2 gears together.

Not a trans I have studied but I assume its hydraulic control, there's often a sprag clutch on autos that allows 1 to change smoothly to 2, it could be seized. There's also this mob you could try:

Wholesale Automatic Transmissions

I got plenty of help from the Australian4wd forum when I had my Frontera. I just had a quick look in the Jackaroo Technical section and see a few posts for Auto problems. See if the following link helps. (Not sure but you may have to sign up to view.)

http://forum.australia4wd.com/index....roo-technical/

I stuggled with an asian warner in a 2.6 jakaroo for a few weeks.
a piston in a clutch pack was a 2 stage idea .apply then hold.

the in between oring failed and wasnt available so it was tried to hold before it applied-this would up set timing and so it applied a clutch as it was ready for the next gear.

im certian they would have sprag clutches but i also think they apply the clutches for every gearpart of making these a little extra heavy duty.

we ended up using creseda parts as the originals often arnt serviced..

With only one reply on the Aus4WD forum,It would seem that I'm the only Jackaroo owner that has ever experienced this problem. Anyway I think I may have isolated the problem to a blockage in the filter pickup. By rolling the vehicle foward down a long 25degree slope on my property, and having the transmission in reverse and controlling the descent with the throttle, in addition to rolling down in reverse with trans in low seems to have dislodged the obstruction, so now the vehicle drives normally. When I have a spare couple of hours I'll remove the oil pan and open up the filter to see what's inside.
Bill.