I very recently purchased a DJ-20 jointer. I believe that this machine is about 20 years old. In starting a tune up on the machine, I immediately noted that the end of the out feed table drops off just under 1/4". I have read several articles about shimming the ways, but nothing to this degree. It seems like an extreme amount and I'm not sure where to begin. I'm somewhat new to wood working and know that there are many experienced voices on the Creek. Any comments would be appreciated.