AM121972 PTO Clutch Replacement for John Deere STX38, STX46 Black Deck | Serial 270001+
AM121972 PTO Clutch Replacement for John Deere STX38, STX46 Black Deck | Serial 270001+
Overview
This AM121972 PTO clutch replacement is an aftermarket electric PTO clutch for select John Deere STX38 and STX46 black deck lawn tractor applications.
Important STX38 fitment warning: John Deere STX38 clutch fitment can vary by deck color, serial range, and original clutch number. This AM121972 listing is for the black deck STX38 / STX46 clutch path, commonly associated with serial number 270001 and higher. Do not order this clutch for a yellow deck STX38 unless your original clutch number matches AM121972.
This clutch replaces John Deere AM121972 and cross-references Warner 5217-8, 5217-20, 5217-36, 5217-38, Oregon 84-003, and Stens 255-141.
Built with a 1-inch crankshaft bore, 5.20-inch pulley diameter, and counter-clockwise rotation, this clutch is designed to restore reliable mower deck blade engagement when matched to the correct original clutch number and physical specs.
If you are comparing STX deck versions or diagnosing blade engagement problems, see our John Deere STX PTO clutch replacement guide.
Key Features
- Aftermarket electric PTO clutch replacement for listed John Deere STX applications
- Crankshaft Bore: 1"
- Pulley Diameter: 5.20"
- Rotation: CCW from pulley side
- Voltage: 12V DC
- Connector Style: connector style as shown in product photos
- Encapsulated electromagnetic coil for reliable blade engagement
- Sealed bearing assembly for mower deck operating conditions
- Fully assembled and ready to install after fitment verification
Compatible Brands & Models
This PTO clutch fits select John Deere STX Series lawn tractors using the AM121972 clutch path. Fitment depends on deck color, serial range, original clutch number, bore size, pulley diameter, rotation, connector style, and overall clutch height.
- John Deere STX38: select black deck applications, commonly serial number 270001 and higher
- John Deere STX46: select black deck applications using AM121972
Fitment note: If your mower is an STX38 yellow deck, do not rely on the STX38 model name alone. Match the original clutch number before ordering. Yellow deck and black deck STX38 tractors can use different PTO clutch paths.
Have a yellow deck STX38? See the AM100979 PTO clutch replacement for John Deere STX38 yellow deck. This AM121972 page is for the black deck STX38 / STX46 clutch path, so match your original clutch number before ordering.
Replaces OEM Part Numbers
- John Deere: AM121972
Additional part-number references: Cross-reference data also lists Honda 80186-VK1-003 and Solo 183990600. This product page is written for the John Deere AM121972 STX black deck fitment path, however this clutch is confirmed as a valid replacement for those part numbers as well.
Aftermarket Cross-Reference Numbers
- Warner: 5217-8, 5217-20, 5217-36, 5217-38
- Oregon: 84-003
- Stens: 255-141
What’s Included
- Complete electric PTO clutch assembly
- Factory-balanced 5.20" pulley
- Pre-installed bearing assembly
- Encapsulated electromagnetic coil
- Connector style as shown in product photos
Why Buy From PTO Direct USA?
- Fast USA shipping
- fitment guarantee
- 1-year warranty
- Fitment-first product support
- Clear product images for easier clutch identification
- Trusted replacement supplier for homeowners, repair shops, and mower service professionals
FAQ
Does AM121972 fit every John Deere STX38?
No. The John Deere STX38 has different clutch paths depending on deck color, serial range, and original clutch number. This AM121972 listing is for select black deck STX38 and STX46 applications, commonly serial number 270001 and higher. If you have a yellow deck STX38, verify the original clutch number before ordering.
Is this the correct clutch for a yellow deck STX38?
No. If your John Deere STX38 has a yellow deck, see the AM100979 PTO clutch replacement instead. This AM121972 listing is for select black deck STX38 / STX46 applications, commonly associated with serial number 270001 and higher.
What bore size does this clutch use?
This clutch uses a 1-inch bore. Confirm your crankshaft size before ordering.
What pulley diameter does this clutch use?
This clutch uses a 5.20-inch pulley diameter. Compare your original clutch and product photos before ordering.
What rotation does this clutch use?
This clutch uses counter-clockwise rotation, commonly written as CCW. Match rotation to your original clutch before installing a replacement.
Can PTO Direct USA help me confirm STX38 fitment?
Yes. Email support@ptodirectusa.com with your mower model number, serial number, deck color, original clutch number, and clear photos of the old clutch. For STX38 tractors, include a photo showing whether the mower has a black deck or yellow deck.
For model-specific fitment help, see the STX38 PTO clutch replacement page and STX46 PTO clutch replacement page.
Need help checking crankshaft size? Read the PTO clutch bore size guide.
Need help with rotation? Read the PTO clutch rotation guide.
If your old clutch will not come off the crankshaft, read the PTO clutch stuck on crankshaft guide before prying or hammering.
Need a different John Deere clutch? Browse the John Deere PTO clutch collection or the full electric PTO clutch catalog.