RZT50 618-04126 Rebuild Kit Fits for Cub Cadet MTD RZT50 RZT50VT ZT50 Troy Bilt Mustang XP 50" Deck, 3 Spindles 618-04125 918-04125, 3 Blades 742-04053, 742-04053 Idlers 754-04044 Belt 734-0415 Wheel

What It Is

This is a comprehensive rebuild kit for 50-inch zero-turn mower decks, specifically designed for Cub Cadet RZT50, RZT50VT, ZT50, and Troy-Bilt Mustang XP 50” models. It includes three spindles, three blades, two idler pulleys, a drive belt, and a wheel, making it a one-stop solution for a full deck overhaul.

Fitment & Compatibility

• Deck size: 50-inch cutting deck only. Do not use on 42”, 46”, or 54” decks.
• Models: Cub Cadet RZT50, RZT50VT, ZT50; Troy-Bilt Mustang XP 50”. Also fits some MTD-built 50” zero-turn mowers.
• OEM vs aftermarket: This is an aftermarket kit. OEM part numbers referenced: spindles 618-04125/918-04125, blades 742-04053, idlers 754-04044, belt 734-0415. Cross-check your existing parts against those numbers.
• Measurements: Blades are 18.5” long, 2.5” wide, with a 1” center hole and 0.25” thickness. Spindles have 5/8” output shafts. Belt is 1/2” wide x 117.5” long. Verify these dimensions on your current parts before ordering.

Key Things to Know

• Quality variance: Some users report spindles failing sooner than OEM (especially bearings). If you mow commercially or on rough terrain, consider OEM spindles separately.
• Installation difficulty: Moderate. Requires removing the deck, swapping spindles, blades, idlers, and belt. Expect 2–4 hours for a first-timer. Have a torque wrench and a spindle puller on hand.
• Blade balance: The included blades are often not balanced out of the box. You’ll need a blade balancer and a file to correct any imbalance before installation.
• Belt routing: Check your deck’s belt diagram—this belt may require a specific routing pattern not shown in generic instructions. Take photos before disassembly.

Should You Buy It

Buy this kit if you need a complete deck rebuild on a budget and are comfortable with moderate DIY work. It’s a solid value for homeowners with a single RZT50 or Mustang XP 50” mower, but if you demand maximum longevity or run a commercial fleet, invest in OEM spindles and blades separately.