GCCSJ Lawn Mower Spindle Replacement Part Number 918-06991 618-06991 Compatible with MTD Troy-Bilt Craftsman Columbia Huskee Murray 42 inch Deck Lawn Tractors Mandrel Assembly, 2 Pack

What It Is

This is a replacement spindle assembly (mandrel) for the 42-inch cutting decks on select MTD-built lawn tractors. It houses the pulley and bearings that spin the blade—critical for a clean, even cut.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: Only fits 42-inch decks. Measure your deck width if unsure.
• OEM numbers: Cross-reference your old spindle’s part number with 918-06991 or 618-06991. This is an aftermarket replacement for those OEM parts.
• Brand/model: Compatible with MTD, Troy-Bilt, Craftsman, Columbia, Huskee, and Murray tractors using a 42-inch deck. Common models include Troy-Bilt Super Bronco, Craftsman LT1000/LT2000, and Murray 42-inch riders. Check your owner’s manual or existing spindle for exact fit.

Practical check: Measure the spindle shaft diameter (typically 5/8-inch) and bolt pattern (usually 4-bolt, 3-inch center-to-center). The pulley is pre-installed—confirm your belt width matches (usually 1/2-inch or 5/8-inch).

Key Things to Know

• Quality: Aftermarket, but rated 4.9/5 from 13 reviews. Bearings are sealed and greased—should last 1-3 seasons under normal use.
• Installation difficulty: Moderate. Requires removing the deck, unbolting the old spindle, and transferring the blade. A ratchet, socket set, and possibly a puller for stuck spindles.
• Common gotchas:
  • The included bolts may be metric vs. your tractor’s SAE. Have a tap/die set or replacement hardware ready.
  • Deck thickness varies—check that the spindle’s mounting flange thickness (about 1/4-inch) matches your deck’s boss.
  • Always replace spindles in pairs on 42-inch decks to avoid imbalance and vibration.
• Warranty: No specific info—treat as a budget part. Buy from a seller with returns.

Should You Buy It

If you have an MTD-built 42-inch deck tractor and need a cost-effective, drop-in replacement for worn spindles, this is a solid pick. The high rating suggests it works well for most users. Skip it if you need a premium OEM part or have a non-42-inch deck.