An important and easily overlooked item of the Hi-Lo lift system is the guide rod. If not properly maintained you could have a problem someday. The guide rod is mounted near and parallel to the hydraulic cylinder that lifts the upper half of the trailer. If if starts to bind it can get bent and cause the lift system to stick and at worst can result in a bent hydraulic cylinder. You should check it periodically to make sure it is clean and greased. If you find it to be looking on the cruddy side, which it probably will be, clean it with a rag and something that will cut grease buildup, such as, kerosene. Then give it a good coating of all purpose grease. This is a simple operation that could save you allot of aggravation and expense.