The Mack TD700 front turn signal requires a 3457NA bulb size while the rear turn signal uses a 1157 bulb size. The replacement chart covers vehicle production years from 2011 to 2017 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mack TD700 uses two distinct bulb types across its front and rear turn signal positions for the 2011-2017 model years: the 3457NA for the front and the 1157 for the rear.
The 3457NA is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and a 7W low filament, conforming to ANSI standards recognized in both the United States and Canada.
The natural amber glass of the 3457NA produces a color-filtered output directly from the bulb itself, rather than relying on an amber-tinted lens housing to achieve the required turn signal color.
The 1157 is a dual-filament bulb rated at 12V with a 21W high filament and a 5W low filament, also conforming to ANSI standards recognized in both the United States and Canada.
The 1157 uses a BAY15d bayonet base, a two-pin offset bayonet mount that physically prevents incorrect single-filament substitutes from seating properly in the socket.
The 3457NA uses a wedge base, which differs mechanically from the BAY15d bayonet base of the 1157, making the two bulb types non-interchangeable between the front and rear positions.
Both the 3457NA and the 1157 carry dual-filament designs, a configuration that allows a single bulb to serve both a steady-state function and a higher-intensity signaling function within the same housing.
The 3457NA front bulb operates its high filament at 27W, which is notably higher than the 1157 rear bulb's 21W high filament, resulting in a greater light output at the front turn signal position.