I have a D4-7U with a 4A blade. I removed the hydraulic cylinders the other day for rebuild. When I removed the retainer from the front mount, I noticed the bushing completely missing. As a result, the pin that the ram rests on has excessive wear. I plan on getting a replacement bushing (3F9363) but I would like to replace the pin. My parts book shows a part number 3F9897 for the pin that the ram mounts to, but shows no other attachment pieces. Does this pin screw onto the crank assembly? Is it welded on? Supposing I can find one, I would like to replace the worn pin so I don't waste a good bushing. I just need to know if it is a weld on or bolt on pin.