Need to be real careful adjusting the axle because it's real easy to get it out of parallel to the Jack-shaft or engine drive sprocket. I would much rather adj. the front spindle.
I've never seen one with adjustment pills. You can probably adjust up and down for cross and/or front to back for axle lead. I'd be careful with adjusting that if you're not sure. Like Jack said, best to adjust wedge with the front.