Max and Monty are two Devious and Troublesome Dumptruck Twins. They are numbered 15 and 16.
Max and Monty were reckless, rude, devious and troublesome. Despite this, They were being good hearted when they are sternly scolded by Miss Jenny.
- Season 7: Stanley, Whiff, and The Troublesome Dumptrucks
- Season 8: A Challenge for the Controller
- Season 12: Greetings, Montague! (not named; do not speak)
- Season 13: The Duke of Hazard (do not speak), Ivo Hugh's Day at the Zoo (cameo)
- Season 15: Jock Beats the Clock (cameo), The Island Of Misfit Engines (cameo)
- Season 16: Sweet Sixteen (cameo), Luke Dukes It Out (cameo), Knock it Off, Stanley (cameo)
- Season 17: Hard to Handel (cameo), Oliver Confusion (cameo), Thomas' Crown Affair (cameo), and Para-Norman Activity (cameo)
- Saving Pirate Ryan (Max only; Monty cameo)