The OEM pins have zerks but I do not think grease is an issue with regards to these failures. My problem was the pin falls out when the retaining bolt breaks. Bouncing on rough roads will surely break these small bolts regardless of grade. Once a pin has fallen out (upper or lower) the BH is free to roam off the hinge plates and damage will occur with that much weight blowing in the breeze. Damage can occur while tractor jostles down the rough path or while in use, slewing with one pin gone will throw the BH off the frame hinge plate and the cyl will break off.
The cap is not the only solution, i.e. weld on a retaining clip across the top, build a catch screen on bottom, etc. I am lucky to have work at a place that can easily machine stuff but would think a simple design such as mine would not be very expensive at most machine shops. IF your dealer is a real good guy, he may know someone in the machine shop biz to solve this at a very reasonable price. If the replacement BH has not resolved thie original issue, you may well face this problem again and be that much poorer for it.
