Trolling Motor Shaft question

[Doonbuggy]

The locking collar on my Minnkota does not move up and down on the shaft real well. Would Gunk (white lithium grease) solve the problem? Something else? I have not put on b/c I'm not sure how it would affec the water once it's in.

Thanks in advance.

DB

[Surface Tension]

Road dirt will stick to most lubricants and make the matter worse. Wash the shaft and collar then use a car wax, let dry and wipe off.