What Fatfenders said; In the old days we preferred the closed drive shaft in Florida grass lands. I used my 54-3100 for that after it's first restoration in 1977. We had to survey our tobacco field and it was full of wire grass. My brother in law had a new Silverado it was all wrapped up. It took a few minutes and a sharp knife to undo but, the rear u-joint lost a cap. Taped it up with wire and drove slow to the bunk house. Drove the 54 to NAPA. Does not happen often but here a skid guard is still a necessity around Okeechobee. Doc