At work we had an F450 towed in because the rear wheels locked up. We found the pinion nut backed off and shoved the pinion through the bottom of the case. First time I've ever seen that happen.
I"ve seen the scuff marks on the carrier from the pinion being loose, but never seen one poke out the bottom!
A big truck lost his pinion as I was following on the Interstate years ago. The whole pinion dropped out of the rear! I couldn't avoid it. It hit the transaxle case of my Saab Aero and blew oil all over the turbo and exhaust. The smoke looked like an old Nascar blown engine.
"Yea, she's making a whole lot a noise, but I think we can make it home, lets run her straight down the highway, its a few miles shorter...." A 1/2 mile down the road, a big BOOM, and locked up rear tires. Man what a ride that would have been!
As a lifelong drag racer, I've seen a lot of carnage, even doing a fair bit of my own. I've had the differential spider gears exit clear out of the rear cover, I've sheared the pinion gear head clean off, I've broken the transaxle case clean in two on my VW drag car, spitting the contents out onto the starting line. I've had more axle, and ring & pinion failures than I care to think about. But I don't think I've EVER seen anything like that!
The Jalopy Journal
