ACEBRI 917-05121 917-04376 PTO Clutch for Cub Cadet/Mtd/Troy Bilt: 717-04376 717-05121 917-05121, for Cub Cadet RZT-L42(08,10-12), RZT-S42(2013 and 2014), for Warner: 5217-53/44 Mower Clutch

What It Is

This is a replacement electric PTO (power take-off) clutch for zero-turn and lawn tractors, engaging the mower blades via a 12V DC electromagnetic coil. Designed for Cub Cadet, MTD, and Troy-Bilt models, it’s a direct swap for OEM part numbers 717-04376, 717-05121, and 917-05121, and also fits Warner clutch 5217-53/44.

Fitment & Compatibility

Check these before buying:

• Model year & deck size: Confirmed fit for Cub Cadet RZT-L42 (2008, 2010-2012) and RZT-S42 (2013-2014). Verify your machine’s model and year—serial number on the frame tag is best.
• OEM cross-reference: This replaces 717-04376, 717-05121, and 917-05121. If your original clutch has a different number, measure the shaft diameter (typically 1” or 7/8”) and bolt pattern (3-hole, 4.5” bolt circle common). Warner 5217-53/44 users: confirm pulley width matches.
• Physical dimensions: Clutch outer diameter ~5.25”, pulley width ~1.25”. Measure your old clutch’s overall thickness (including pulley) to ensure clearance on your deck. If yours is thicker or thinner, this may not fit.
• Wiring: Single-wire connector (ground through chassis). If your machine uses a two-wire setup, you’ll need to splice or adapt.

Key Things to Know

• Quality vs OEM: Aftermarket unit at ~$95, while OEM Cub Cadet clutches run $150-200. Users report similar lifespan (2-4 seasons) under normal residential use, but some note slight vibration at high RPM. Not ideal for heavy commercial mowing.
• Installation difficulty: Moderate. Requires removing the deck, belt, and center bolt (usually 15/16” or 1-1/8”). You’ll need a torque wrench to tighten the shaft nut to 40-50 ft-lbs. No special tools beyond basic sockets and a puller if the old clutch is seized.
• Common gotchas:
  • The clutch may come with a plastic shipping spacer on the pulley—remove it before install.
  • If your old clutch failed due to a bad coil, test the 12V supply at the connector first (engine running, PTO switch on). Low voltage or a blown fuse can kill a new clutch quickly.
  • Check the air gap (0.010-0.020”) between the rotor and armature. If too wide, the clutch won’t engage; too tight, it drags.

Should You Buy It

If you have a compatible Cub Cadet RZT-L42 or RZT-S42 and want a budget-friendly replacement for occasional residential mowing, this clutch is a solid value. For commercial use or if your original lasted less than 2 seasons, consider spending more on an OEM unit for better consistency. Skip it if your model isn’t listed—verify fitment first to avoid a return.