The International 5500i front turn signal uses a 3157NA bulb size while the rear turn signal requires a 1157 bulb size. The replacement chart covers vehicle production spanning 2011 to 2014.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International 5500i uses two distinct bulb types across its turn signal positions for the 2011-2014 model years: the 3157NA at the front and the 1157 at the rear.
The 3157NA is an ANSI-standard dual-filament wedge bulb in the T25 form factor, rated at 12V with a 27W high filament and a 7W low filament, and features natural amber glass rather than a clear envelope.
The 1157 is an ANSI-standard dual-filament bulb fitted with a BAY15d bayonet base, rated at 12V with a 21W high filament and a 5W low filament.
Both bulb types conform to ANSI standards applicable in the United States and Canada, meaning they share a common regulatory framework despite differing in base type and wattage.
The natural amber glass of the 3157NA produces a filtered amber output directly from the bulb, which differs from clear-envelope variants that rely on a colored lens to achieve the same effect.
The dual-filament design of both bulbs allows a single unit to serve two lighting functions, typically a brighter output for active signaling and a dimmer output for a running or parking light role.
The BAY15d bayonet base of the 1157 features two offset pins, a physical characteristic that prevents incorrect insertion and distinguishes it from single-filament bayonet bulbs with a different pin arrangement.
The 3157NA and 1157 are not interchangeable with each other, as they differ in base type, physical form factor, and wattage ratings.