918-06978 618-06978 Spindle Assembly for 54 Inch Mower Decks Cub Cadet RZT-S54 L54 ZT1-54 ZT2-54 XT1-ST54 GT54 XT2-54 GX54 Troy Bilt TB2454 Craftsman T8400 G8400 Z6660 (3-Pack)

What It Is

This is a 3-pack of spindle assemblies designed for 54-inch mower decks on select Cub Cadet, Troy Bilt, and Craftsman zero-turn and lawn tractors. It replaces the OEM part numbers 918-06978 and 618-06978, which are the rotating hubs that drive the mower blades.

Fitment & Compatibility

• Deck size: Only for 54-inch decks. Measure your deck width to confirm—this won’t fit smaller or larger decks.
• Models: Cub Cadet RZT-S54, L54, ZT1-54, ZT2-54, XT1-ST54, GT54, XT2-54, GX54; Troy Bilt TB2454; Craftsman T8400, G8400, Z6660. Check your model number plate under the seat or on the frame.
• OEM vs aftermarket: This is an aftermarket replacement, not OEM Cub Cadet. It’s a direct fit for the listed models but verify your existing spindle’s bolt pattern and shaft diameter (typically 1-inch shaft, 3-bolt flange).
• Measurement check: Measure center-to-center bolt spacing on your old spindle (usually 3.75 inches). If it matches, this will bolt on.

Key Things to Know

• Quality: Users report solid build with grease fittings for relubrication, which OEM spindles often lack. Expect good durability for residential use.
• Installation difficulty: Moderate—requires removing the deck, old spindles, and blade pulleys. Have a socket set, torque wrench, and penetrating oil on hand for stubborn bolts.
• Common gotcha: The pulleys from your old spindles must be reused (not included). Ensure your pulley’s center hole and keyway match before starting.
• 3-pack value: Buying individually costs more. This pack covers all three spindles on a 54-inch deck, saving time and shipping.

Should You Buy It

If you own a compatible 54-inch Cub Cadet, Troy Bilt, or Craftsman mower and need to replace worn or failed spindles (common after 200-500 hours), this 3-pack offers good value for residential use. It’s a reliable aftermarket option with greaseable bearings, but skip it if you prefer OEM parts for commercial-grade durability.