Helping a friend (UPDATE with a pic)

Thanks for all the replies guys!!! Just confirms my own thoughts. I will post back when I get it done. He was towing his 5er when his truck broke down. He has a 6 speed manual transmission, and that is what he thinks went out. He said when the tow truck came out to pick up his truck that the back wheels were locked!
On the bright side, this will make for some awesome campfire conversation about how the ol' Ford had to come rescue the ol' Dodge!!! (Just saying) LOL