My boat is 1997 Tracker, bought used, has Minn Kota 37lb thrust. I don't think the motor has that much time on it, the owner didn't fish this boat much but there is slop in the linkage and when it kicks in, it's kind of noisy and jerky. How can I fix this? If parts are needed, where can I buy? It doesn't seem like it would have enough mileage for this to be worn out but maybe time does it damage?

Try lubricating the mechanism with white lithium grease.  I use a soldering brush that's readily available in any hardware store.

 

Get a small tube of the grease, put a drop on the brush and apply to every part that moves or rubs against other metal parts.  A drop of grease goes a long way.  It will make your unit operate easily and smoothly.  Be sure to get the pins and the "ramps" that lock and release the trolling motor to deploy it or stow it.

 

The brush is also good for applying a thin coat of grease to a trailer hitch.  I know some don't like to lubricate the hitch because it can make a mess.  But I hate the squeaking and squawking of a dry hitch.