The phrase "keep shoulder to wheel" means to continue working hard and persistently towards a goal. There are several different synonyms that can be used to convey the same message. For instance, "stay the course" means to remain focused and committed to a task or objective. "Stick with it" conveys the idea of persistence and determination in the face of obstacles. "Stay on track" suggests the need to stay focused and maintain progress towards a goal. "Keep at it" emphasizes the importance of continuing to work towards a goal, regardless of setbacks or challenges. Ultimately, all of these phrases convey the idea of staying the course and continuing to work hard in pursuit of one's objectives.