618-06991 918-06991 Spindle Assembly Fits for MTD Craftsman Troy Bilt 42 inch Deck LT4200 CLT42G T1200 Super Bronco Pony TB2246 2 Pack

What It Is

This is a replacement spindle assembly for the cutting deck of select MTD, Craftsman, and Troy-Bilt lawn tractors. It drives the mower blade and includes the housing, bearings, shaft, and pulley – sold as a 2-pack for 42-inch deck models like the LT4200, CLT42G, T1200, Super Bronco, Pony, and TB2246.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: This spindle fits 42-inch decks only. Measure your deck width (cutting path) to be sure.
• Model/series: Works with MTD-built Craftsman (LT4200, CLT42G), Troy-Bilt (T1200, Super Bronco, Pony, TB2246), and similar. Check your mower’s model number under the seat or on the frame.
• OEM vs aftermarket: This is a direct replacement for OEM part numbers 618-06991 and 918-06991. It is not an OEM part but matches dimensions, bolt pattern, and shaft length. Verify the pulley diameter (usually 3.5–4 inches) and spindle shaft length (approx. 3.5 inches) match your old unit.

What to measure: Center-to-center bolt spacing (typically 3.5 inches) and spindle shaft diameter (usually 5/8 inch). If your deck uses a different bolt pattern or shaft size, this won’t fit.

Key Things to Know

• Quality: Most users report good fit and smooth operation, but some note the bearings may not last as long as OEM. Grease the bearings before installation to extend life.
• Installation difficulty: Moderate. You’ll need a socket set, a jack or blocks to lift the mower, and a blade removal tool. Plan 30–60 minutes per spindle.
• Common gotcha: The pulley may be pre-installed or loose. If loose, tighten the center bolt to spec (usually 30–40 ft-lbs). Also, check blade bolt torque (40–50 ft-lbs) after installation.
• Deck alignment: Replacing one spindle? Replace all three at once on a 42-inch deck to avoid uneven cutting and vibration.

Should You Buy It

If you own a 42-inch MTD/Craftsman/Troy-Bilt tractor with a worn or noisy spindle, this 2-pack is a solid value. It’s a reliable aftermarket option for DIY repairs, especially if you’re replacing multiple spindles at once. For heavy commercial use, consider OEM for longer bearing life; for home use, this is a smart buy.