AR North America AR1670 XW Gear Box 1:2 Ratio SAEJ609A Flange 1750 RPM by | Jul 24, 2026Part Number AR1670. Series 178 (XW Series). XW Series (178): Part of AR’s professional-grade tri-plex gear box lineup. Max RPM 1750 RPM. Pump RPM 1750 RPM. 1750 Max RPM: Rated for high-performance pump drive applications.