Tom.JTC
Active Member
Most common cause is the linkage has ceased or come disconnected if used little. I've heard of a build up of mud and dirt that's stopped it from working, cleaned it out and it worked again. Someone else will be able to give you a better description then I can of how to fix it if it's disconnected. 
jamesmartin
Well-Known Member
what engine ?diff lock mechanism often seizes in high/low d/l lever housing where shaft goes through housing on lh side, linkage on rh side has a pivot screwed into gear box ,plastic bushes wear or are often missing causing too much play ,pivot can be screwed futher in/out to adsjust lever so that it will fully select diff lock and release it ,best done with one front wheel jacked up ,where linkage meets transfer box is a 13mm nut turning this clockwise when looked from above selects diff lock anticlock wise puts it out of diff lock,in the transfere box diff selector is operated by a spring,tensioned by lever so that just because lever is over to lh hand side doesnt mean diff lock selector has actually moved ,it is operated through a spring so diff lock can be selected on the move as long as wheels arent slipping
