Attention: TDR Forum Junkies 
DM, I would guarantee the sound you heard was an exhaust brake. I buy and sell farm equipment and always have a gooseneck behind me pulling heavy loads and it's quite hilarious the comments I hear when I roll into an auction yard with my brake on yet and the older crowd hears the whoosing sound coming thru my stacks. I heard one guy say to another once that the there truck must have a jet engine in it if I ever did hear one. Or another I always hear is must be a souped up diesel to haul them tractors with.
One time I pulled into a truck/tractor pull by the pit areas to help a friend with his modified tractor and a guy who had come with his 12 valver Dodge loaded up and left before it began because he came to win cash and was terrified to pull against me and break his truck trying to win and I didn't even have any intention of pulling and I didn't but was in the pit area only because I had the toolbox in my truck box. Some people that knew him came over to me after the end of the modified truck pulls and asked why I never hooked and told me he had left because I had pulled in with my exhaust brake on and he thought I was SUPER modified. Sure was good humor after the pulls.
One time I pulled into a truck/tractor pull by the pit areas to help a friend with his modified tractor and a guy who had come with his 12 valver Dodge loaded up and left before it began because he came to win cash and was terrified to pull against me and break his truck trying to win and I didn't even have any intention of pulling and I didn't but was in the pit area only because I had the toolbox in my truck box. Some people that knew him came over to me after the end of the modified truck pulls and asked why I never hooked and told me he had left because I had pulled in with my exhaust brake on and he thought I was SUPER modified. Sure was good humor after the pulls.
