8 3/4 hard to rotate wheels

Being a non-Sure Grip, chances are the thrust transfer is a 1 piece unit, but I would pull both axles & look down both tubes & be sure everything's where it belongs. And that
nothing that doesn't belong there isn't, :eek:, lol!! Your goal is to have both axles close to the same distance from the backing plates, then get the end-play set maintaining that.
My method wasn't by the book, but I snugged mine up 'till there was zero play, rapped the axle w/the adj. w/a hammer on a block of wood, then re-snugged if needed to zero
play. Backed the adj. up 'till it caught the next notch & installed the lock, always worked for Me.