04387900 PTO Clutch Replacement for Ariens Gravely | Replaces 4387900

Overview

This Ariens Gravely PTO clutch 04387900 replacement also replaces 4387900 and cross-references Xtreme X0588, Ogura GT1A-EH07, Ogura 53594500, Stens 255-066X, and Rotary 15772. It is designed for select Gravely ZT HD zero-turn mower applications that use this 1-inch bore, 6-inch pulley electric PTO clutch setup.

Commonly used on Gravely ZT HD 44", 48", 52", and 60" deck models, this clutch helps restore smooth blade engagement, proper belt drive speed, and dependable mowing performance under heavier deck loads.

Key specs include a 6.00-inch pulley diameter, 1-inch crankshaft bore, CCW rotation, and an integrated water-tight wiring lead. For best fitment, match your original clutch number and compare the main specs before ordering.

Key Features

• Direct replacement electric PTO clutch assembly for select Ariens / Gravely zero-turn mower applications
• Pulley Diameter: 6.00"
• Crankshaft Size: 1"
• Rotation: CCW (counter-clockwise)
• Voltage: 12V DC
• Belt Width Compatibility: 1/2" or 5/8" A/B belt profile
• Integrated water-tight wiring lead
• Designed for reliable blade engagement on supported ZT HD deck setups
• Fully assembled and ready to install after fitment verification

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Compatible With These Brands & Model Series

This PTO clutch fits select Gravely ZT HD zero-turn mowers whose official parts diagram identifies 04387900 as the clutch assembly.

Gravely ZT HD Applications

• 991082 – ZT 48 HD: serial 010000 and up
• 991083 – ZT 52 HD: serial 010000 and up
• 991084 – ZT 60 HD: serial 010000 and up
• 991090 – ZT 44 HD: serial 010000 and up
• 991091 – ZT 60 HD: serial 000101 and up
• 991098 – ZT 44 HD CARB: serial 020000 and up
• 991099 – ZT 48 HD CARB: serial 020000 and up
• 991100 – ZT 52 HD CARB: serial 020000 and up
• 991101 – ZT 60 HD CARB: serial 020000 and up

Part-number-first fitment: The official Ariens/Gravely engine-and-clutch diagram lists 04387900 as the Ogura clutch assembly for these model paths. Confirm the complete six-digit mower model, six-digit serial number, and original clutch number before ordering.

Model names and deck sizes alone are not enough to confirm fitment. Gravely produced similar ZT and ZT HD mower families with different clutch, pulley, wiring, and mounting configurations.

Model, Serial Range & Adapter Harness Notes

Some early 020000-series ZT HD mowers use the same 04387900 PTO clutch with a separate 04411600 clutch adapter harness.

• 991090 – ZT 44 HD: adapter harness 04411600 listed for serial 020000–022219
• 991091 – ZT 60 HD: adapter harness 04411600 listed for serial 020000–020141
• 991082 – ZT 48 HD: adapter harness 04411600 listed for serial 020000–022448
• 991083 – ZT 52 HD: adapter harness 04411600 listed for serial 020000–021876
• 991084 – ZT 60 HD: adapter harness 04411600 listed for serial 020000–021811
• 991098 – ZT 44 HD CARB: adapter harness 04411600 listed for serial 020000–022010
• 991099 – ZT 48 HD CARB: adapter harness 04411600 listed for serial 020000–022014
• 991100 – ZT 52 HD CARB: adapter harness 04411600 listed for serial 020000–020034
• 991101 – ZT 60 HD CARB: adapter harness 04411600 listed for serial 020000–020007

Important: These serial ranges are not exclusions from 04387900 clutch fitment. They identify machines whose electrical-system diagram also includes the OEM 04411600 adapter harness.

Inspect the mower-side connector before installation. Reuse the original adapter harness when required unless a compatible replacement harness is specifically included with the clutch.

Ariens Zoom and Max Zoom note: Ariens/Gravely also identifies 04387900 for select Max Zoom applications, but those machines are not covered by the ZT HD model table above. Confirm the complete Ariens model and serial number through its own parts diagram rather than applying the ZT HD serial ranges.

Replaces OEM Part Numbers

• Ariens / Gravely: 04387900, 4387900
• Ogura: GT1A-EH07, GT1AEH07, 53594500

Manufacturer & Aftermarket Cross-Reference Numbers

• Xtreme: X0588
• STENS: 255-066X
• Rotary: 15772

What’s Included

• Complete electric PTO clutch assembly
• Factory-balanced 6.00" pulley
• Pre-installed bearing assembly
• Electromagnetic coil
• Integrated wiring lead

Note: Engine mounting hardware, anti-rotation brackets, and external adapter harnesses are not included. Reuse your original OEM hardware and adapter harness where required.

How to Confirm Fitment

The most reliable way to confirm compatibility is to match the OEM part number stamped on your original PTO clutch. If the number is worn or unreadable use model fitment information then carefully compare the 6.00-inch pulley diameter, 1-inch crankshaft bore, CCW rotation, wiring connector, and anti-rotation bracket slot before installation.

A matching mower brand or model name alone does not guarantee fitment. Similar Ariens and Gravely machines can use different PTO clutch families depending on serial number, engine package, deck size, production year, wiring style, and chassis design.

Why Buy From PTO Direct USA?

• Fast USA shipping
• Fitment Guarantee
• 1-year warranty
• Premium product images for easy identification
• Trusted replacement supplier for homeowners and professionals

Need a different fitment? Browse the full electric PTO clutch catalog to see all available replacement options.