UP2WIN 918-04126 Spindle Assembly, 618-04126 Spindle Compatible with MTD Cub Cad et i1050 LT1050 RZT50 50" Lawn Mower Deck, Replace for 918-04125 618-04125 918-04126B, 3 Pack

What It Is

This is a replacement spindle assembly for the 50-inch MTD/Cub Cadet fabricated decks found on models like the RZT50, LT1050, and i1050. It houses the pulley and bearings that spin the mower blade, and it comes as a 3-pack to replace all three spindles at once.

Fitment & Compatibility

Before buying, verify these three things:

• Deck type: This fits only 50-inch fabricated (steel) decks, not stamped decks. Check your deck’s construction—fabricated decks have a flat, welded plate; stamped decks are pressed sheet metal.
• OEM cross-reference: Replaces OEM part numbers 918-04126, 918-04125, 618-04125, 618-04126, and 918-04126B. If your mower uses any of those, this is a direct swap.
• Physical check: Measure the spindle housing height (approx. 4.5 inches) and bolt pattern (3-bolt, 2.75-inch center-to-center). Confirm your existing pulley and blade bolt size (usually 5/8-inch or 1-inch) match.

Key Things to Know

• Quality vs. OEM: These are aftermarket spindles. Reviews indicate they’re comparable to OEM for residential use, but some users report slightly shorter bearing life under heavy commercial use.
• Installation difficulty: Moderate. You’ll need a socket set, a jack or blocks to lift the mower, and a blade removal tool. Expect 1–2 hours for all three spindles.
• Common gotcha: The included bolts may be metric (M8) while your deck uses SAE (5/16-inch). Have a set of both on hand, or reuse your original bolts if they’re in good shape.
• Bearing grease: These come pre-greased. Don’t add extra grease—overpacking can cause seal blowout.

Should You Buy It

If you own a 50-inch Cub Cadet or MTD with a fabricated deck and your spindles are noisy, wobbling, or leaking grease, this 3-pack is a cost-effective time-saver. It’s a solid choice for the DIY homeowner who wants to replace all three spindles at once and avoid downtime. Skip it if you’re running a commercial operation or need a perfect OEM match.