A transmission??!! Thank God no one got killed. Chalk another up to morons dropping their junk on the hwy... The cops need to start nailing some of these guys who refuse to secure their loads properly.

A couple of years ago there was a girl down here who got killed when some guy let a big roll of carpet fall out of the back of his truck. Then there was the child that was killed by a spare tire that dropped off a pickup. Oh, and then the local DJ who got killed when a flatbed lost a forklift. Total stupidity.

I hope you figure out what's wrong, obviously that could be very dangerous. It does sound kind of like a broken strut, but it could be a lot of things. You might get under it with a flashlight and take a look. It might not be showing up when all the load is off the wheels, which I presume is the only way they looked at it (on a rack)