8.75 Sure Grip axle end play - left side

I think you're not cranking on the adjuster enuff.. or there's a burr or something..

Do you have the proper wrench,, or are you banging on the adjuster with a hammer and screwdriver..?

Are there lots of threads still exposed from the adjuster plate/nut.. ie .. there ARE threads left to go??

Perhaps try loosening the axle retainer nuts enuff to crank a full turn on the adjuster,, then tighten the retainer back with the nuts, check backlash,, it should be less than before,, then the same proceedure till backlash is achieved..

hope it helps