The 03789900 PTO clutch is a commercial electric PTO clutch replacement used on select Gravely Compact-Pro, Gravely Pro-Master, Gravely Pro-Stance, Gravely Pro-Walk, and related Ariens mower platforms. This clutch family is commonly cross-referenced with 3789900, Ogura GT1A-AR03, Ogura GT1AAR03, and Rotary 15783.
If your mower blades will not engage, the clutch clicks but the deck belt does not move, or the blades slow down under load, this clutch family may be one of the first replacement groups to check. The safest way to confirm fitment is to match the OEM number stamped, engraved, printed, or labeled on your original PTO clutch.
If your original clutch matches this family, view the direct replacement here: 03789900 PTO clutch replacement.
Need help confirming fitment? Email support@ptodirectusa.com with your mower model number, serial number, OEM clutch number, and clear photos of the old clutch, wiring connector, pulley, and deck belt routing.
03789900 PTO Clutch Replacement Specs
The 03789900 clutch family is built for commercial mower platforms where pulley size, crankshaft bore, rotation, wiring, and deck belt alignment must match the original clutch closely.
- Primary replacement number: 03789900
- Related OEM number: 3789900
- Crankshaft bore: 1-1/8 inch
- Pulley diameter: 6.10 inches
- Rotation: CCW from pulley side
- Operating speed: up to 3600 RPM
- Design: electric PTO clutch with electromagnetic coil
- Common application type: commercial zero-turn, stand-on, walk-behind, and compact commercial mower platforms
Fitment warning: Do not choose a PTO clutch by appearance alone. Confirm the original clutch number, crankshaft bore, pulley diameter, pulley offset, rotation, wiring connector, and anti-rotation bracket position before installation.
Replaces OEM and Interchange Part Numbers
This 03789900 PTO clutch replacement is commonly used to replace the following OEM and interchange numbers:
- 03789900
- 3789900
- Ogura GT1A-AR03
- Ogura GT1AAR03
- Rotary 15783
If your original clutch shows one of these numbers, the 03789900 PTO clutch replacement may be the correct fit when the physical specs and mower application also match.
Compatible Gravely Models
This clutch family is commonly associated with selected Gravely commercial mower platforms. Model names alone are not enough for final confirmation, so always match the clutch number and specs before ordering.
Gravely Compact-Pro
- Compact-Pro 34
- Compact-Pro 44
Gravely Pro-Master Series
- Pro-Master 34M
- Pro-Master 34Z
- Pro-Master 44Z
- Pro-Master 48Z
Gravely Pro-Stance Stand-On Mowers
- Pro-Stance 1934FX
- Pro-Stance 2048FL
- Pro-Stance 2048FX
- Pro-Stance 2052FX
- Pro-Stance 2452FL
- Related 36-inch, 48-inch, 52-inch, 60-inch, and 61-inch deck configurations
Gravely Pro-Walk Commercial Walk-Behind Mowers
- Pro-Walk 36HR
- Pro-Walk 48
- Pro-Walk 48HE
- Pro-Walk 52
- Pro-Walk 52HE
- Pro-Walk 60
- Pro-Walk 60HE
For broader Gravely routing, see the Gravely PTO clutch replacement guide or browse the Gravely PTO clutch collection.
Compatible Ariens Models
Some Ariens commercial platforms are also associated with the 03789900 clutch family. Confirm by original clutch number before ordering.
- Ariens Pro-Master 34Z
- Ariens Pro-Zoom 1952S
For broader Ariens fitment help, see the Ariens PTO clutch replacement guide or browse the Ariens PTO clutch collection.
Do Not Confuse 03789900 With Other Gravely PTO Clutches
Gravely and Ariens commercial platforms use several PTO clutch families. A clutch can look similar and still use a different bore size, pulley diameter, pulley offset, connector, or mounting setup.
03789900 vs. 59118600
The 59118600 clutch family is a different heavy-duty replacement group commonly tied to 05191600, 126-8926, and 126-4324. It uses a different fitment path than 03789900. If your original clutch shows one of those numbers, use the 59118600 PTO clutch fitment guide.
03789900 vs. 110-6766
The 110-6766 clutch family is commonly tied to selected Ariens Zoom, Gravely Pro-Master, Gravely ZT, Toro, Exmark, and Warner 5219-series applications. Do not substitute 110-6766 for 03789900 unless the original clutch number and physical specs confirm the match.
03789900 vs. 126-8925
The 126-8925 clutch is commonly associated with selected Ariens Apex, Gravely ZT HD, and Pro-Turn Z applications. It should not be treated as the same clutch family as 03789900 without matching the original clutch number and specs.
Common Symptoms of a Failing 03789900 PTO Clutch
A failing PTO clutch can cause blade engagement problems, belt movement issues, heat, noise, or intermittent operation. These symptoms can also be caused by wiring, voltage, belt routing, idler pulleys, or deck spindles, so inspect the system before replacing parts.
- Mower blades will not engage
- PTO clutch clicks but blades do not spin
- Deck belt does not move when the PTO is activated
- Blades engage intermittently
- Blades slow down or stop under load
- Burning smell near the clutch or belt
- Grinding, squealing, or bearing noise near the clutch
- Clutch gets hot during mowing
- Blown fuse or electrical issue when PTO is activated
If your blades will not engage at all, start with the PTO clutch won’t engage troubleshooting guide. If the clutch clicks but the blades do not spin, use the PTO clutch clicks but blades won’t spin guide. If the clutch slips under load, see the PTO clutch slipping under load guide. If the clutch gets hot or smells burnt, read the PTO clutch getting hot or smells burnt guide.
How to Confirm Fitment Before Ordering
The most reliable way to confirm compatibility is to match the OEM number stamped, engraved, printed, or labeled on your original PTO clutch. If the number is missing or damaged, compare the clutch dimensions and mower details.
- Match the original clutch number, such as 03789900, 3789900, Ogura GT1A-AR03, or Rotary 15783
- Confirm the crankshaft bore is 1-1/8 inch
- Confirm the pulley diameter is 6.10 inches
- Confirm CCW rotation from the pulley side
- Compare the wiring connector or lead style
- Check the anti-rotation bracket position
- Confirm the mower model, serial number, engine setup, and deck size
- Inspect deck belt routing, idlers, and spindle drag before installing a new clutch
Not sure where to find the clutch number? Use the PTO clutch fitment guide before ordering.
Before Installing the Replacement Clutch
Before installing a new PTO clutch, inspect the mower for issues that can damage the replacement.
- Check the deck belt for glazing, cracks, oil, or wear
- Confirm the belt is routed correctly around the clutch pulley, idlers, and spindle pulleys
- Make sure idler pulleys and blade spindles spin freely
- Inspect the wiring connector for corrosion, loose terminals, or heat damage
- Inspect the crankshaft for rust, burrs, or keyway damage
- Confirm the anti-rotation bracket is properly positioned
Review the PTO clutch installation guide before installing the replacement. If the old clutch is stuck on the crankshaft, see the PTO clutch stuck on crankshaft guide before forcing removal.
Shop 03789900 PTO Clutch Replacement
If your original clutch is marked 03789900, 3789900, Ogura GT1A-AR03, Ogura GT1AAR03, or Rotary 15783, and the core specs match, shop the 03789900 PTO clutch replacement.
You can also browse the Gravely PTO clutch collection, Ariens PTO clutch collection, or the full electric PTO clutch catalog.
Related Gravely and Ariens Guides
- Gravely PTO Clutch Replacement Guide
- Gravely Pro-Master PTO Clutch Replacement
- Gravely Pro-Stance PTO Clutch Replacement
- Gravely Pro Series PTO Clutch Replacement
- Ariens PTO Clutch Replacement Guide
- 59118600 PTO Clutch Fitment Guide
- 110-6766 PTO Clutch Fitment Guide
Helpful PTO Clutch Resources
- 03789900 PTO Clutch Replacement
- PTO Clutch Fitment Guide
- PTO Clutch Installation Guide
- PTO Clutch Won’t Engage Troubleshooting Guide
- Shop All Electric PTO Clutches
FAQ
What does the 03789900 PTO clutch replace?
The 03789900 PTO clutch commonly replaces 3789900, Ogura GT1A-AR03, Ogura GT1AAR03, and Rotary 15783. Confirm the original clutch number and physical specs before ordering.
What mower platforms commonly use this clutch?
This clutch family is commonly associated with select Gravely Compact-Pro, Pro-Master, Pro-Stance, Pro-Walk, Ariens Pro-Master 34Z, and Ariens Pro-Zoom 1952S applications.
What crankshaft bore does 03789900 use?
The 03789900 clutch family uses a 1-1/8 inch crankshaft bore.
What pulley diameter does this clutch use?
This clutch family uses a 6.10-inch pulley. Confirm the pulley diameter on your original clutch before ordering.
Is 03789900 the same as 59118600?
No. The 03789900 and 59118600 clutch families are different replacement groups. Match the OEM number, bore size, pulley diameter, pulley offset, connector style, and mower application before ordering.
Can PTO Direct USA help me confirm fitment?
Yes. Email support@ptodirectusa.com with your mower model number, serial number, OEM clutch number, and clear photos of the old clutch. For the best fitment help, include photos of the clutch label or stamped number, wiring connector, clutch pulley, deck belt routing, and any visible Warner or Ogura numbers on the clutch body.