3 Pack 918-06978 Spindle Assembly with 756-05034A Idler Pulley 954-04329A Belt 5/8x149 Replaces 618-06978 for Cub Cadet RZT L54 Kh Fab Carb, ZT1 54 Kh Fab, Z6600 Lawn Tractors

What It Is

This is a three-piece replacement set for the cutting deck on select Cub Cadet zero-turn mowers. It includes two spindle assemblies (918-06978), one idler pulley (756-05034A), and one drive belt (954-04329A, 5/8" x 149"). Designed for 54-inch fabricated (Kh Fab) decks on RZT L54, ZT1 54, and Z6600 series tractors, it replaces worn spindles, a seized idler pulley, or a stretched belt in one shot.

Fitment & Compatibility

Before buying, verify your mower’s model and deck type. This fits Cub Cadet models with a 54-inch fabricated deck (Kh Fab)—not stamped steel decks. Check your OEM part numbers: original spindles are 618-06978, idler pulley is 756-05034A, and belt is 954-04329A. Measure your belt length (149 inches) and width (5/8 inch) to confirm. Aftermarket set, so confirm your machine’s year and serial number against Cub Cadet parts diagrams. Common compatible models: RZT L54, ZT1 54 (fabricated deck), Z6600, and some Kh Fab Carb models.

Key Things to Know

• Quality note: Aftermarket set with solid reviews (4.7 stars). Spindles include bearings and housings; idler pulley is steel with sealed bearing. Not OEM, but close fitment.
• Installation difficulty: Moderate. Requires basic tools (wrenches, socket set, jack/stands to lift deck). Expect 1–2 hours. Replace all three spindles at once if one fails to avoid uneven wear.
• Common gotchas: Deck belt routing is critical—use a diagram or take a photo before removing. The idler pulley bracket must be torqued to spec (check manual). Spindle bolts can be seized; use penetrating oil.
• Belt note: 5/8" x 149" belt fits most 54" fabricated decks, but double-check your deck’s belt path for tensioner placement.

Should You Buy It

Buy this if you own a Cub Cadet with a 54-inch fabricated deck and need to replace worn spindles, a bad idler pulley, or a stretched belt. It’s a cost-effective bundle for a full deck service, ideal for DIY owners who want to avoid dealer labor costs. Skip if you have a stamped steel deck or need OEM-specific parts for warranty.