The guys face a huge challenge when a big dollar collector asks them to slam a 1969 Chevy C10. Meanwhile, Heavy D and the guys are off to bike week at Sturgis, to check out a one-of-a-kind hydrostatic diesel motorcycle.

When the local Sheriff asks for a new Search and Rescue vehicle, the guys are excited to build an amphibious Sisu Nasu. And the diesel guys pull out all the stops for their next work truck giveaway- a Dodge 5500 with all the bells and whistles.

When Heavy D adds a second truck to their latest giveaway, he comes up with an insane stunt to promote it- a race across a lake on snowmobiles. And the guys head to Houston with giant diesel trucks and supplies to help Hurricane Harvey victims.

A new client asks for the biggest build yet- a monster school bus capable of driving over sand and water. And The Muscle brings in his own client build for a gym buddy- a Raptor-style F250.

A new client asks for the biggest build yet- a monster school bus capable of driving over sand and water. Redbeard discovers the Mello Yello racecar from Days of Thunder and the perfect buyer for it.

A client asks Heavy D and his crew to turn a Ford F550 into a tough 6x6 farm truck that's also a rolling showcase for biodiesel fuel. Heavy D uses the power of physics to drive a truck on just two wheels.

A client asks Heavy D to turn a Ford F550 into a tough 6x6 farm truck that's also a showcase for biodiesel fuel, and the guys make their dreams come true when they build the first diesel Monster Jam truck.

Major league pitcher Jacob deGrom asks them to revamp his OBS Ford, and the diesel guys convert a rare British Land Rover Defender from right hand drive to left hand drive for a client.

The guys pull out all the stops on a build for their lawyer Cole-converting a rare Land Rover Defender from right hand drive to left hand drive. And Heavy D tries to get more money to the shop by parting out a military airplane de-icer.

The Diesel Brothers give a truck overhaul to a local dad who was harassed at a campsite when his F350 broke down. And the guys put together the shop's first-ever diesel Motorcycle, with a Magneto!

When the guys are challenged to a Tuff Truck race by their former mechanics, Chet and Tyson of Goon Garage, Sparks Motors rebuilds a wasp-infested old Jeep and the Goons rebuild a water-logged Blazer.

Heavy D and Diesel Dave source a 1984 AMC Eagle they want to turn into their next big, diesel-powered build.

Heavy D and the crew transform a rundown logging truck into a maxed out, custom semi to transport their builds cross country. And Diesel Dave and the Muscle go head to head building two ultimate Diesel Daily Drivers for their next truck giveaway.

While the shop finishes the semi build, Heavy D moves full steam ahead with his plan to attempt a death-defying stunt in the Brodozer. To complement the jump, Heavy D plans a live giveaway inspired by one of their most popular builds, the US Duramax.

Heavy D buys a busted one-of-a-kind rock crawler and gives it the Sparks Motors treatment for a quick flip. Meanwhile, a friend commissions a 1,000 gallon fuel truck and two custom diesel-powered fertilizer spreaders for his helicopter business.

Heavy D attempts to salvage a wrecked overland camper from Europe he bought at auction. Meanwhile, the team races to complete a 1,000 gallon fuel truck and two custom diesel-powered fertilizer spreaders for a helicopter operation.