Clive, Ive just noticed that your signature says you have ARB lockers - even better!
For the benefit of others who may find themselves in this situation and to jog my own memory as i never thought about this earlier today:
Air operated diff locks like ARB, Ashchroft and McNamara are normally wired up electrically so you cant lock the front without the rear being engaged as well. If you need to limp home on tarmac the less you have locked the better as it all creates wind up stresses across the axle or in the transfer box and props in the case of a locked centre diff. However if you swap the air lines around you can use the rear switch to engage the front air locker and drive home in high range with an open centre diff. No front to back wind up and none across the front axle as you only have one wheel driving. The rear diff would be open in this scenario as normal.
Ten second bodge!
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