918-06980 618-06980 Spindle Assembly Kit for 50 inch Deck Cub Cadet RZT 50 S50 L50 ZT1 50 XT1 50 GT50 Troy Bilt Mustang 50 Craftsman G8200 Z550 Zero Turn Mower Parts (3 Pack)

What It Is

This 3-pack of spindle assembly kits (OEM numbers 918-06980 / 618-06980) replaces the entire rotating hub, bearings, and shaft that drive your mower blades on 50-inch decks. Designed for Cub Cadet, Troy-Bilt, and Craftsman zero-turn and lawn tractors, it’s a direct-fit service part for decks that use a 5/8-inch spindle shaft with a 3-inch blade mounting pattern.

Fitment & Compatibility

Before buying, verify these three things:

• Deck width: Only fits 50-inch cutting decks. Not for 42, 46, 54, or 60-inch decks.
• Model family: Confirmed fit on Cub Cadet RZT 50, S50, L50, ZT1 50, XT1 50, GT50; Troy-Bilt Mustang 50; Craftsman G8200, Z550. Also fits some MTD-built 50-inch decks.
• Spindle shaft: Measures 5/8-inch diameter. If your original spindle has a 3/4-inch shaft or a different blade bolt pattern, this won’t fit.
• OEM vs aftermarket: This is an aftermarket replacement, not genuine Cub Cadet. Housing material and bearing quality may differ slightly, but dimensions match OEM specs.

Quick check: Pull one blade and measure the spindle shaft diameter with a caliper. If it’s 5/8-inch and uses three bolts to hold the blade, you’re good.

Key Things to Know

• Quality: Bearings are sealed and pre-greased. Users report they hold up well for residential use but may not last as long as OEM in commercial/daily mowing.
• Installation: Moderate difficulty. You’ll need a socket set, torque wrench, and possibly a puller to remove old spindles. New spindles come with bolts and lock washers—do not reuse old hardware.
• Common gotcha: The spindle housing is aluminum. Over-torquing the blade bolts can strip the threads. Use a torque wrench and stick to 40-50 ft-lbs.
• Pack value: Buying a 3-pack is cheaper than three singles. If you only need one or two, check if the brand sells individual spindles.

Should You Buy It

If you have a 50-inch Cub Cadet, Troy-Bilt, or Craftsman zero-turn or lawn tractor and need to replace worn or wobbly spindles, this 3-pack is a solid value for the price. It’s best for homeowners who want a complete refresh without buying OEM. Commercial operators or those with heavy use should consider genuine Cub Cadet spindles for longer bearing life.