918-04126 618-04126 Spindle Assembly Fit for Cub Cadet/MTD/Troy Bilt 50 Inch Deck RZT50 LT1050 LGTX1050 Lawn Mower, Replace 618-04125A 918-04125B 618-04125 (3 Pack)

What It Is

This is a 3-pack of spindle assemblies designed for 50-inch deck zero-turn and lawn tractors from Cub Cadet, MTD, and Troy-Bilt. Each spindle houses the bearings and shaft that spin the mower blade, critical for a clean, even cut.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: Only for 50-inch decks. Models include RZT50, LT1050, LGTX1050, and similar MTD/Troy-Bilt platforms.
• OEM numbers: Replaces 618-04125A, 918-04125B, and 618-04125. Cross-check your existing spindle’s part number.
• Physical check: Measure the spindle shaft diameter (typically 5/8-inch) and bolt pattern (3-bolt, 3-inch spacing). Verify the pulley mount style matches your deck.

Avoid this if your deck is 42-inch, 46-inch, or 54-inch—different spindle assemblies required.

Key Things to Know

• Quality: Aftermarket but rated 4.9/5; includes sealed bearings pre-greased. Comparable to OEM, though some users report slightly shorter bearing life under heavy use.
• Installation: Moderate difficulty. You’ll need a socket set, torque wrench (30-40 ft-lbs for spindle bolts), and a jack or blocks to lift the deck. Expect 1-2 hours for all three.
• Common gotcha: Pulley and blade removal can be stubborn due to rust. Soak with penetrating oil beforehand. Do not reuse old lock nuts—use new ones.
• Check deck alignment: After installation, ensure all three spindles are level and blades clear the deck housing by 1/4-1/2 inch.

Should You Buy It

Buy this if you own a 50-inch Cub Cadet, MTD, or Troy-Bilt with worn or noisy spindles and want a cost-effective 3-pack replacement. It’s a solid value for DIY repairs, but if you need maximum longevity for commercial mowing, consider OEM spindles instead.