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Servicing the air compressor or accessory drive system on legacy Cummins NT, NH, or 855-series diesel engines? Attempting to extract press-fit splined couplers using generic two-jaw pullers, pry bars, or torch heat distorts precision spline teeth, scores drive shafts, and ruins front gear case bearings. Made for continuous heavy-duty shop use, the M20040 Air Compressor & Accessory Drive Coupler Puller provides a 360-degree collet/jaw engagement system and centered forcing screw to apply 100% axial pulling force, popping interference-fit splined couplers off shafts without damaging critical engine components.

The Critical Physics of Splined Coupler Extraction & Driveline Protection

Legacy Cummins heavy-duty diesel engines—including the legendary 855, NT, and NH series—utilize high-torque splined drive couplers to connect the front gear train to the air compressor and accessory drive shafts. Operating under high torsional loads, extreme heat cycling, and decades of service, these press-fit splined hubs become severely bound to their shafts. Because these specialty couplers lack threaded puller holes, technicians often make the mistake of hooking standard three-jaw gear pullers onto the outer lip or jamming pry bars behind the hub. Standard jaw pullers concentrate enormous side-loads onto small contact points, flaring the outer coupler sleeve, galling the drive shaft splines, or cocking the shaft inside the front gear case housing. A cocked shaft side-loads internal accessory drive bearings, leading to rapid bearing failure, gear alignment errors, and severe oil leaks. The M20040 Air Compressor & Accessory Drive Coupler Puller completely eliminates these service hazards. Featuring a custom-engineered collet/jaw assembly, it wraps 360 degrees around the splined hub to distribute pulling force uniformly across the entire component geometry. Turning the high-tensile central forcing screw applies dead-straight axial tension directly along the centerline of the shaft, pulling the press-fit coupler off smoothly without spline galling, shaft scoring, or housing shock loading.

• Dedicated Cummins NT/NH/855 Fitment – Engineered specifically for press-fit splined air compressor and accessory drive couplings across Cummins 855, NT, and NH diesel platforms.
• Specialized Collet/Jaw Engagement System – Grips unthreaded splined hubs uniformly 360 degrees to prevent component deformation and edge flaring.
• Centered Axial Forcing Screw Mechanics – Delivers 100% straight-line mechanical pulling force to protect drive shafts, splines, and internal gear case bearings.
• Eliminates Torch Heat & Torch Damage – Safely breaks tight interference fits without requiring open flames that degrade shaft temper or melt front oil seals.
• Heavy-Duty Industrial Tool Construction – Substantial 3.00 lbs solid alloy steel build designed to withstand continuous daily use in commercial overhaul stalls and rebuild bays.

Stop Prying Splined Hubs. Command Total Cummins Accessory Drive Teardown Precision.

The M20040 Cummins Air Compressor & Accessory Drive Coupler Puller – Splined Coupler Tool is an essential capital asset for heavy-duty truck repair centers, commercial fleet maintenance stalls, industrial generator technicians, and engine rebuilders. Protect drive shafts, preserve precision splines, and service Cummins accessory drives with complete mechanical authority using Apex tools.

Technical Specifications

Technical Metric	Value / Fitment Reference Guidelines
Target Engine Platforms	Cummins NT, NH, and 855-Series Heavy-Duty Diesel Engines
Primary Operational Function	Extraction of press-fit splined air compressor and accessory drive couplers
Gripping Mechanism Type	Full-perimeter 360° collet / jaw-style engagement housing
Part / Model Reference Number	M20040 (M20040 / 20040)
Construction Metallurgy	High-tensile forged and precision-machined structural tool steel
Total Package Shipping Weight	3.00 lbs (Substantial, professional shop service tool)

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