The Junkyard Airvan Rebuilt Around a Mercedes OM617
Charles Lorenzo turned a forgotten 1958 Lyn Airvan into a four-wheel-drive work truck with a turbodiesel heart and an unusually thorough mechanical rebuild.
A $4,000 Van Hidden Under Mold
The 1958 Lyn Airvan was easy to miss. Brush and mold concealed its body, while Harley-Davidson parts filled the interior. Charles Lorenzo of Bensalem, Pennsylvania, saw a usable foundation rather than a dead relic and spent two and a half years persuading its owner to sell. The final price was $4,000.
The van came with almost no history. No exterior markings explained its former life, leaving the VIN on the steering column as the only identifying clue. That uncertainty did not stop the project; it gave Lorenzo time to decide what the Airvan should become before turning a wrench.
The original Chevrolet chassis carried a seized 235-cubic-inch inline-six gasoline engine. Reviving it was never part of the plan. Lorenzo instead mapped out a complete transformation, then spent another two years converting the neglected shell into a roadgoing four-wheel-drive machine.
The OM617 Swap Dictated the Build
Lorenzo found the replacement powertrain in a 1984 Mercedes-Benz 300D donor car. Its OM617 turbodiesel inline-five became the Airvan’s centerpiece, joined by the Mercedes radiator, electric cooling fan, and four-speed automatic transmission. The combination gave the unusual van a drivetrain chosen for its durability reputation rather than originality.
Four-wheel drive was equally deliberate. After more than 50 years of off-road experience, Lorenzo installed a divorced Ford Highboy NP205 transfer case. A twin-stick shifter purchased through Amazon was modified to fit the Airvan, adding a hands-on control arrangement to a van never designed around this drivetrain.
Jeep hardware completed the conversion. Both axles came from a 1999 Jeep Grand Cherokee, while manual-locking-hub components from an earlier axle updated the Dana 30 front end. The differentials retained their factory 3.73:1 gearing, keeping the axle package internally consistent.
Original Leaf Springs, Reworked Around New Axles
The four-wheel-drive conversion did not lead Lorenzo to discard the Airvan’s suspension. He rebuilt the factory leaf springs and retained them, fitting the existing chassis with the Jeep axles rather than replacing the entire suspension architecture.
The finished van runs 225/75R16 Firestone Transforce LT tires on Ford F-150 aluminum wheels. Those details matter to ownership because they identify the rolling hardware as a deliberately assembled combination, not a catalog conversion performed with one matched kit. Tire size, wheel choice, axle width, steering geometry, and brake placement all had to coexist beneath a body designed in 1958.
Lorenzo first removed the body from the chassis and built a custom rotisserie. He then cleaned and refinished the frame before reassembly. That sequence exposed the structure before the new drivetrain and running gear made access difficult, turning corrosion cleanup into part of the build rather than an afterthought.
Forty-Seven Circuits Made Wiring the Hard Part
The mechanical work was only one portion of the conversion. Lorenzo began with an Amazon-sourced wiring harness, then reworked it as the Airvan accumulated lighting, cooling, instrumentation, and accessory systems. He described wiring the vehicle’s 47 different—and counting—circuits as the hardest part of the process.
The electrical upgrades include all-new LED lighting and electric windshield wipers in place of the original vacuum-operated units. Dolphin gauges provide the cabin instrumentation, including a GPS speedometer. These additions change the daily driving experience without pretending the van is still mechanically stock.
Steering and braking also required adapted parts. A Jeep Compass rack-and-pinion system handles steering, while a Jeep Grand Cherokee brake master cylinder was modified for the project. Lorenzo fabricated a custom engine doghouse and built a one-off heating, defroster, and air-conditioning system around the Mercedes installation. Every replacement solved a packaging problem specific to this Airvan.
A Daily Driver, Not a Display Piece
The Airvan had been on the road for only about two months when Ken Brubaker and Charles Lorenzo photographed it at the 2026 4-Wheel Summer Jamboree Nationals in Bloomsburg, Pennsylvania. Its public debut came before the project was fully finished, but Lorenzo already had a clear use for it: daily transportation and a work truck for helping members of his church with home-improvement projects.
Further work remains. New flat glass is installed, while paint, seating, and tool shelving are still planned. Those jobs are practical finishing steps rather than a change in direction. The van’s layout is being completed around regular use, including the equipment it will carry and the passengers it will transport.
Lorenzo identifies the central achievement as making an original truck frame and suspension work with four-wheel drive, his preferred diesel engine, and its transmission. He also enjoys driving his grandkids in it. The result is rare because of its body, but memorable because the engineering is meant to keep it moving.
