I suppose you could clean it out and adjust it in the truck, although it might be just as much work as pulling it out. If it drives as nice as you say, just top off the grease / lube and drive it as is. When the seal starts leaking then think about cleaning and rebuilding. I use a 00 grade grease in mine I purchased from a vender at work. John Deere sells a 00 grade grease for the corn head gear boxes on combines, any dealer can get it and each tube is around $3.00 hear in the Kansas City area. 00 grade is self leveling, meaning if flows back in on itself, it looks like really really thick gear oil. Pen-rite sells a gear box grease also.
Joe
