Do your tailgates rattle on your Jackaroo? If so, maybe it is time to check the adjustment. The right hand gate essentially provides the only tension in holding both gates tight against the body as the left side is locked onto the right. So simply, if the right is not tight then the left will tend to rattle. But the clever people at Isuzu recognised this problem and fitted an anti-rattle device at the bottom of the left gate.
The anti-rattle device operates as the body flexes and the gate moves, gradually making the gate tighter. This is achieved by a sliding spring loaded wedge rubbing on a ramp. It is desirable that the wedge be able to move easily. Now take a look at your gates and check the operation of the wedge. It is still there, isn’t it? In many cases dust and muck have effectively jammed the wedge from moving and causing the steel ramp on the frame to wear – even to the degree of creating a flat spot without ramp. Now check the rubber seal around the door opening for wear. This will generally suffer along the bottom edge where items are slid in over the sill. If the seal is worn or broken in places then maybe you should consider getting a replacement – yes a new one is still listed by Holden but somewhat expensive!
Adjustment: Set up the right gate by adjusting the position of the catch on the bottom of the door frame to give a snug fit. Then adjust the steel ramp to ensure that it provides maximum effect. If the ramp or wedge is worn then you might consider replacement although it is possible to build up the ramp by either a spacer under it or by brazing with bronze and grinding or filing back to shape. You can check whether the wedge is sliding in tight by smearing the ramp with petroleum jelly and driving over some rough patches and opening the gates and noting where the wedge has slid up the ramp. If the wedge has moved into the limit of its travel then maybe you will need to fit a spacer under the ramp. Regular cleaning and some petroleum jelly on the ramp will be effective but the down-side of the lubrication will be dust collection so some dry lube, such as graphite dust is preferred. Keep some lube in an accessible place so that each time you open the gate you can check the ramp.
A final comment, higher tyre pressures will improve your fuel economy but may highlight any looseness and rattles in the gates.