The guys hope to score on the auction block with a rare diesel Cadillac.

Heavy D enlists a unique semi-amphibious off-road military vehicle that gives Redbeard a sinking feeling. Meanwhile, time's up for the Diesel Bi-Wheel, and they're left questioning its big debut.

Redbeard goes rogue taking on an iconic diesel vehicle build of his own. Will his Hail Mary cost them a Queen's Ransom? Meanwhile it's time to see if the Gama Goat will sink or swim -- literally.

Heavy D rolls the dice on a vintage 1951 International Diesel dozer with engine problems. Is he pushing his luck? Meanwhile, Redbeard announces their first-ever double giveaway to keep some cash flowing into the shop.

The guys get fired up about an overlanding rig, but it turns into a totaled smoke show. Can Heavy D save the day or is the auction going up in flames?

Heavy D bets the farm on a Diesel-swapped Chevy 210, but this rusty Rat Rod could run them off the road. Meanwhile, they're giving away a monstrous new TRX.

Work continues on the Diesel rat rod, but Heavy D's latest military build hits a snag.

Heavy D takes a chance on a unique double Corvette; Muscle takes the lead on a Denali for their latest giveaway.

Auction day is finally here and the guys are selling 16 unbelievable builds in the biggest gamble of their careers.