918-04126 918-04125 618-04125 918-04126B Spindle Assembly - Fits 50 Inch Mower Decks MTD Cub Cadet RZT50 ZT50 LTX1050 SLT1554 i1050 LT1050 LGT1050 (3-Pack)

What It Is

This is a 3-pack of spindle assemblies designed for 50-inch mower decks on select MTD and Cub Cadet lawn tractors and zero-turn mowers. The spindle houses the pulley and blade mount, transferring engine power to rotate the cutting blade.

Fitment & Compatibility

• Deck size: Only fits 50-inch mower decks. Measure your deck width before buying.
• Brands/models: Fits Cub Cadet RZT50, ZT50, LTX1050, SLT1554, i1050, LT1050, LGT1050, and compatible MTD models with a 50-inch deck.
• OEM cross-reference: Replaces OEM part numbers 918-04126, 918-04125, 618-04125, 918-04126B. Verify your original spindle number.
• Physical check: Measure spindle shaft diameter (typically 1 inch) and bolt pattern (2-bolt or 3-bolt). Count pulley grooves (usually 2 or 3) and compare to your old spindle.
• Mounting hardware: Not included—reuse your existing bolts or buy new ones.

Key Things to Know

• Quality: Aftermarket part, but rated 4.8/5—most users report it matches OEM fit and durability.
• Installation difficulty: Moderate. Requires removing deck, belt, pulley, and blade. Need basic tools (socket set, wrench, penetrating oil for rusted bolts).
• Common gotcha: Spindles may not include grease fittings or seals. Check if your old ones had them; if so, pre-grease before install.
• Belt alignment: After install, ensure pulley aligns with deck belt path. Slight misalignment can cause belt wear or throwing.

Should You Buy It

If you have a 50-inch MTD or Cub Cadet mower with a worn or noisy spindle, this 3-pack is a cost-effective fix. It’s best for DIY owners who want to replace all three spindles at once to avoid future downtime. Not for other deck sizes or brands.