The weight and speed I believe was one of the big problems--like with the Humvee as they progressed they just overloaded them, at the start the deuce gun trucks were single walled with just a couple gunners with their personal weapons, then they added more protection with sand bags and double walled armor, with the rain and all they got real heavy, then adding maybe a M-60 and with gunners never having enough ammo they only got heavyer, the roads were beating them up pretty bad---then more and more trans units were getting 5 tons and the deuce was having a harder time keeping up, also they began adding the 50s and a ton more ammo, in the units that were 2/12 ton units the deuce didn't have that hard a time--(like the 541st)---In 1970 the Ace of Spades (a 5 ton) hit the road at 34,000 lbs---but the deuce is a great truck, here's some photos of the old and newers styles---------------------Just my thoughts------------Driver