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Mazda RX-7 FD

What are the thoughts on using a cog or Gilmer belt drive on a Mazda RX-7 FD?

Updated June 2026

The primary consensus on using a Gilmer (cog) belt drive is that the setup is notoriously "whiney" or noisy 5. Due to this excessive noise, it is common to swap out a Gilmer kit for quieter serpentine or ribbed alternatives.

If you are reconsidering the Gilmer drive for your FD, a few recommended alternatives include:

  • Factory FD Belt Setup: Reverting to the standard Mazda belt configuration.
  • 6-Rib Belt Setup: Upgrading to a wider, modern 6-rib serpentine belt drive.
  • Atkins Serpentine Kit: This is a popular aftermarket replacement to eliminate the Gilmer whine, but keep in mind that it is specifically recommended only if your engine utilizes an FC water pump housing 5.

This answer was generated by GarageBot's AI from enthusiast forum discussions. Always verify torque specs and safety-critical procedures against the factory service manual before working on your car.

Discussed on the forums

  1. Manual Rack and Pinion
  2. Mazda repu manual rack or power steering rack
  3. Over drive ratio (5th gear) availability from other models
  4. 2nd Gen belt pattern
  5. What pulley to get

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