Locking in hubs.

G'Day Ray

The reason the book and most people will tell you not to do that is simply that the rear axles/driveline are not designed to handle the torque load on there own that the lower gearing can produce. With hubs locked in 4x4 H or L the front prop shaft is driven which takes half the load of the rear prop shaft.
I.E. If you were to rev the engine and drop the clutch with low range engaged and hubs unlocked you would stand a good chance of snapping an axle, exploding a transfer case or similar.

It's fine for moving the van or trailer around slowly, just be careful not to apply power or load.

Cheers
Foss

What model Patrol?

Most Patrols have auto hubs that can also be locked. If you have these, when you engage 4WD Hi or Lo you are actually in 4WD. Therefore you are risking wind-up of the drivetrain if you're on a hard surface.

It's also not uncommon to hear of broken axles and tailshafts when using Lo range in 2WD.

Patrol axles are very robust - dont hear of many breaking - you have to drive them like you hate them to even go close to breaking them. No probs using low range 2wd but just go easy.

kes

Thanks for all the replies.