250031-586 Sullair OEM Coupling Kit

The 250031-586 Sullair Drive Coupler Kit is a complete OEM coupling assembly for Sullair 375 portable diesel air compressors and related portable compressor platforms. The kit ships with three (3) drive pins, and three (3) mounting bolts, supplying every component needed for a full coupler service in one part number rather than sourcing each piece separately during a maintenance window.

The 250031-586 is specified on the Sullair 375DPQ-JD, 375 DPQ-JD, 375 DPQJD, and other portable diesel compressors.  The coupler is also used on the 375 John Deere-engine variant and other Sullair 375-class portable units that share the same engine-to-airend driveline architecture.

The coupler connects the diesel engine output shaft to the rotary screw airend input shaft, transmitting full operational torque while compensating for the angular and parallel shaft misalignment that develops during normal operation, thermal expansion, and machine settling on uneven jobsite ground. The pin-driven design provides positive torque transmission with controlled flexibility, protecting the airend bearings, shaft seals, and downstream drivetrain components from the cyclical torsional spikes that diesel engines generate during normal combustion.

When to replace the 250031-586: Inspect this coupler at every scheduled portable compressor service and watch for symptoms including elevated vibration during loaded operation, audible knocking or rumbling from the bell housing area at startup or under load, visible wear on the drive pins, elongation of the pin bores, deformed or set element material around the pin contact points, and metallic debris around the coupling guard. A worn coupler that runs to full failure cascades into airend bearing damage that costs many times the price of a proactive kit replacement.

Direct OEM Sullair replacement — not an aftermarket equivalent. Replace the complete assembly when wear is detected on any single component to restore the drivetrain to OEM specification rather than mixing new and worn parts. Install per the Sullair service manual with verification of shaft alignment, pin fit, and proper torque on the mounting hardware before returning the compressor to service. Available from Stark Industrial Products with same-day shipping on in-stock orders and 24/7 phone support at (903) 768-1111 to confirm 375-series compressor fitment before you order.