There are various synonyms for the phrase 'keeping shoulder to the wheel'. This phrase denotes the act of working hard and tirelessly to achieve a particular goal or objective. Some of the synonyms for this phrase include 'staying the course', 'persevering', 'pushing through', 'slogging away', and 'sticking to it'. Other related phrases that express the same sentiment include 'keeping your nose to the grindstone', 'riding out the storm', 'working like a dog', and 'digging in your heels'. Regardless of the phrasing used, the idea remains the same- that it takes persistence, consistency, and a strong sense of determination to achieve success.