If your miter guide is loose in the track, take a punch and make about 3 indents along each side of the runner (one on each end and one in the middle), if to tight, file untill it fits. This takes all the play out of your miter gage. Joe
What Joe is suggesting will work -- The center punch needs to be placed close to the edge as you are looking down on the gauge and a tap on a hammer will flare the metal out beyond the 3/4" width. Do all of the adjustments on just one side of the bar to keep it dead straight -- if it is too loose, tap them a little deeper; if too tight, file the flared out part slightly and try the fit again. HTH.