Your F3's have horizontal motors or vertical? I use an automotive solvent called "brake cleaner" on the power trucks to remove old grease. Drys quick, no residue. I also use "red n Tacky" on all my gears. Spur and worm gears. If you have horizontal motors in your santa fe" make sure the wheels dont rub against the body of the truck. Bushings may be worn. EZ fix.
bob