NASCAR Truck’s Entire Rear End Fell Off While Racing at COTA

This clip of Andretti's rear end rolling away needs the Curb Your Enthusiasm theme.

I’ve heard of driving the wheels off of race cars but this is ridiculous. OK, bad Seinfeld impressions aside, Marco Andretti quite literally drove the wheels off of his NASCAR Truck at Circuit of the Americas on Saturday. With two laps remaining, Andretti’s entire rear end simply fell off of his truck while driving and rolled off the track onto the grass. There was no crash, nor did Andretti’s truck hit anything on the road. The rear just fell off.

When the rolling rear end finally came to a stop, the TV cameras zoomed in on it and it was all there: the solid rear axle, differential, wheel hubs, coil spring, shocks, wheels, and tires. It was as if someone jacked the truck up, unbolted its entire rear, and then rolled it down the track. The visual of it quietly rolling away desperately needs the Curb Your Enthusiasm theme in the background.

So what exactly happened? It’s hard to tell, as there’s no official statement about what caused Andretti’s rear end to free itself. However, according to this detailed breakdown from The Autopian, it seems like the welds on the truck’s rear trailing arms broke, just ahead of their U-bolts. Why did they break? Again, there’s no official answer but it seems likely that stresses from wheel hop under heavy braking did the trick. According to NASCAR reporter Bob Pockrass, Andretti’s rear end is being reviewed by NASCAR’s R&D center.

Thankfully, losing the rear axle didn’t cause Andretti to crash, nor did it hit any other car. Once the truck’s rear end came off, the race was stopped, so the truck could be towed off and the rear end could be moved. Once the race restarted, Cory Heim—who was leading before Andretti’s truck disintegrated—was able to hold onto his lead for his first win of the season. More importantly, we now have this hilarious clip of a rogue rear end rolling down the track.

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