I was driving about 70MPH on a superslab when I heard this funny whine building over the music on the radio. I turned off the radio and the whine was still building. I backed off the throttle to slow down and the whine reduced in pitch. I pulled over on the side of the highway and about 15MPH the engine made some horrible noises, the truck jerked, and quickly stopped. The engine wouldn't start, and I couldn't push the car when I put the trans in neutral. Had the truck delivered to my mechanic. Turns out I'd been to JiffyLube and the shop apes didn't tighten the plug on the transmission. All the lube leaked out and at high speed the gears melted together. Had a used transmission from a local yard installed by the shop. I have the blackened gearset out in the garage in a box of parts. I have NEVER been back to Jiffylube again.