Bosch SR4239X Starter

Bosch SR4239X Remanufactured Starter

The Bosch SR4239X is a remanufactured 12-volt starter built for dependable engine cranking and consistent starting performance. It is a direct-fit starter for select Mazda applications, including Mazda 3, Mazda 3 Sport, Mazda 5, Mazda 6, and CX-7 models listed below.

Bosch Premium Starters are remanufactured, tested units engineered to deliver reliable operation in everyday driving conditions. The SR4239X uses a clockwise rotation, a closed aluminum nose cone, and an attached solenoid for a straightforward replacement on the correct vehicle application.

Key Features

• 12-volt remanufactured starter for select Mazda vehicles
• 1.4 power rating for starting-system service
• Clockwise starter rotation
• Closed nose design with aluminum nose cone and aluminum finish
• Solenoid attached for simplified replacement
• 11-tooth drive configuration
• 2 mounting bolt holes
• Cross-reference part number: L53818400B

Detailed Description

Bosch SR4239X is a remanufactured starter designed for Mazda starting-system repair where the original unit has worn brushes, weak engagement, slow cranking, or intermittent no-start symptoms. This starter is built to match the listed OE-style application and is intended for vehicles that require a clockwise-rotation, 12-volt starter with an attached solenoid. The Bosch Starter (Remanufactured) line focuses on rebuilt electrical components that are tested for performance and reliability before release.

Compatible With select Mazda applications, including Fits 2013 Mazda 3, N/A, to 09/2012; Fits 2013 Mazda 3 Sport, N/A, to 09/2012; Fits 2011-2013 Mazda 6, N/A; Fits 2006-2008 Mazda 6, N/A; Fits 2010-2012 Mazda 3, N/A; Fits 2010-2012 Mazda 3 Sport, N/A; Fits 2012 Mazda 5, N/A, to 06/2012; Fits 2010-2012 Mazda CX-7, N/A; and Fits 2010 Mazda 6, N/A, from 11/2009. Part number SR4239X is also referenced for this application.

Common Issues This Starter May Resolve

• Engine cranks slowly or inconsistently
• No-start condition caused by starter wear
• Clicking sound when turning the key or pressing start
• Starter engagement problems from a failing solenoid
• Intermittent starting after repeated use

Installation Notes and Tips

• Verify the vehicle build date before ordering, especially for 2013 Mazda 3, 2013 Mazda 3 Sport, 2012 Mazda 5, and 2010 Mazda 6 applications with date-specific notes.
• Confirm the starter rotation, tooth count, and mounting bolt hole layout match the original unit.
• Inspect battery condition, cables, and charging-system output before installing the replacement starter.
• Mounting hardware and shims are not included.
• Professional installation is recommended for proper electrical connection and fitment verification.

Quality Assurance

This Bosch remanufactured starter is built, tested, and inspected to support reliable starting performance in the listed Mazda applications. Bosch’s remanufactured starter program is focused on restoring core electrical function to OE-style standards for direct replacement service.