First, no actual clue on how old this is. Was bought used, and even if I can't repair the thing, I'd say I've gotten my moneys worth by avoiding the laundromat for the past 16 months or so.

On to the issue: The settings dial to select wash type/length etc on the machine doesn't 'catch' to change settings. the knob will spin freely instead of actually moving the selecting arrow. It will let me pull the knob out and start the cycle it's currently on (broke about the final spin on 'gentle' while I was rotating it to start a load). It just seems like the knob does not catch the disk to change the setting. Any ideas on what/where is broke and if I can replace whatever it is myself would be appreciated.

Your timer shaft plastic end is stripped off, you need a new timer AP302050510. You can verify by taking the timer apart. To unscew the knob, you will need to use needle nose pliers to grab the shaft while turning the knob counterclockwise.