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

Compatible With These Brands & Model Series

This PTO clutch fits select Gravely ZT HD models using OEM part number 04387900 or 4387900.

Gravely ZT HD Series

• 991082: ZT 48HD, serial 010000–019999 and 030000 and up
• 991083: ZT 52HD, serial 010000–019999 and 030000 and up
• 991084: ZT 60HD, serial 010000–019999 and 030000 and up
• 991090: ZT 44HD, serial 010000–019999 and 030000 and up
• 991091: ZT 60HD, serial 000101–019999

Fitment can vary by model, serial range, engine package, wiring connector, and original clutch specification. Always confirm your original clutch number and pulley diameter before ordering.

Model & Serial Range Notes

• Gravely 991082 ZT 48HD: fits serial 010000–019999 and 030000 and up
• Gravely 991083 ZT 52HD: fits serial 010000–019999 and 030000 and up
• Gravely 991084 ZT 60HD: fits serial 010000–019999 and 030000 and up
• Gravely 991090 ZT 44HD: fits serial 010000–019999 and 030000 and up
• Gravely 991091 ZT 60HD: fits serial 000101–019999

Critical wiring note: Some 020000-series machines may require the original OEM adapter harness to be reused. If your model 991082 falls between serial 020000–022448, model 991083 between serial 020000–021876, or model 991084 between serial 020000–021811, verify your wiring adapter before ordering.

Disputed fitment warning: Some Ariens Zoom and Gravely ZT 50 listings incorrectly group this 6.00" pulley clutch with machines that use the smaller 5-3/8" pulley clutch family. If your mower is an Ariens Zoom, Gravely consumer ZT, or a model not listed above, measure your original clutch pulley before ordering.

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.