918-05078A Spindle Assembly - Fits 46 Inch Mower Decks, Fits Cub Ca det RZT-S46/L46/LX46/SX46 ZT1/ZT2-46 Crafts man Z6400 Troy-Bi lt Mustang Super Bronco, Replaces 618-05078/05078A 918-05078(1-Pack)

What It Is

This is a replacement spindle assembly for 46-inch mower decks, designed to transfer power from the belt to the blade on zero-turn and lawn tractors. It’s a direct-fit part for select Cub Cadet, Craftsman, and Troy-Bilt models with 46-inch fabricated or stamped decks.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: Must be exactly 46 inches (measured blade tip to blade tip). This spindle will not fit 42-inch or 50-inch decks.
• Model list: Fits Cub Cadet RZT-S46, L46, LX46, SX46, ZT1-46, ZT2-46; Craftsman Z6400; Troy-Bilt Mustang Super Bronco (46-inch). Check your deck’s model number tag—usually stamped near the discharge chute.
• OEM reference: Replaces OEM part numbers 618-05078, 618-05078A, and 918-05078. If your original spindle has a different number (e.g., 618-05100), it will not fit.
• Physical check: Measure the spindle shaft diameter (typically 3/4-inch) and bolt pattern (4-bolt, 3-inch center-to-center). This unit uses a 1-inch shaft length with a 5/8-inch hex for blade mounting.

Key Things to Know

• Quality vs OEM: This aftermarket spindle is solid for the price, but the bearings may wear faster than OEM under heavy use (e.g., thick, wet grass). Expect 1–2 seasons with occasional greasing.
• Installation difficulty: Moderate. Requires removing the blade, pulley, and old spindle housing. You’ll need a 15mm socket for blade bolts and a 1/2-inch ratchet for the spindle bolts. No special tools beyond a standard socket set.
• Common gotcha: The spindle may not include a new pulley or blade washer. Reuse your old pulley if it’s in good shape, but replace the blade bolt (check torque spec: 40–50 ft-lbs).
• Warranty note: It’s a 1-pack at $28.99—if your deck has two spindles, buy two to ensure even wear. No warranty info listed, so inspect for casting flaws before installation.

Should You Buy It

Buy this if you need a budget-friendly, direct-fit spindle for a 46-inch Cub Cadet, Craftsman, or Troy-Bilt zero-turn and are comfortable with basic mechanical work. Skip it if you run a commercial mowing operation or want OEM-grade longevity—invest in a branded OEM spindle instead.