The Ark II vehicle was built on the chassis of a dump truck. The dump truck was notorious for constantly breaking down between shots. It was also reportedly hard to operate in crowded areas safely because the placement of the windows was such that the driver of the Ark was unable to see clearly. The other vehicle, the Ark Roamer, was built on a Volkswagen van chassis from a modified "Brubaker Box" kit, and while it ran well, it had a limited range. The Brubaker group built both vehicles for the series.
There are no night scenes or episodes in "Ark II" because it was impossible to maneuver the Ark at night due to the lack of visibility from the driver's section. Also, each episode had a 2-3 day turnaround, and Jose Flores was still a minor working under strict rules governing child actors. As a result of these factors, plus the Ark's tendency to break down, night shots for episodes were nixed.
All the sound effects inside the Ark II were previously heard as part of the U.S.S. Enterprise on Star Trek (1966). Filmation had these elements in their sound library since they produced the animated Star Trek: The Animated Series (1973).
The chimpanzee who played Adam was named Moochie. Henry J. Lange Jr., a series director, revealed in a DVD special feature that Moochie wore a diaper under his Ark uniform.