You do not need to lubricate your jack plate unless it is shaking even after being cleaned. If your jack plate is shaking when traveling up or down, we first recommend cleaning the jack plate.
To clean the jack plate and remove dirt build-up, first run the plate all the way up and apply a generous amount of dish detergent, then run the jack plate down. Let it soak until the next time you take your boat out. The detergent will push the dirt out and keep your plate running smoothly.
If the problem persists, you may need to lubricate the jack plate. If you have cleaned the jack plate and have a problem with it shaking, lubricate the jack plate with a non-oil or non-grease based lubricant such as a silicon spray.