Mower Spindle Assembly Replace 618-0240 618-0240A 618-0430, 918-0240, for MTD 46" Decks LT546H, LT946H, LT1800, LT1850, LT2150, LT4600H, GT205, GT2150, 1997 and Newer

What It Is

This is a replacement spindle assembly for MTD 46-inch cutting decks, designed to drive the mower blade on zero-turn and lawn tractors. It fits models like the LT546H, LT946H, LT1800, LT1850, LT2150, LT4600H, GT205, and GT2150, covering 1997 and newer units.

Fitment & Compatibility

Before buying, verify three things: (1) your deck is 46 inches wide—measure if unsure, as 42-inch or 50-inch decks use different spindles. (2) Check your original part number: this replaces OEM numbers 618-0240, 618-0240A, 618-0430, and 918-0240. (3) Physically measure the spindle shaft diameter (should be 1 inch) and bolt pattern (typically 4 bolts on 3.25-inch centers). Aftermarket part, not genuine MTD—fits most 1997+ MTD 46" decks but not Craftsman, Husqvarna, or Toro decks unless they share MTD platform.

Key Things to Know

• Quality: Cast iron housing with sealed bearings—holds up well for residential use, but not rated for heavy commercial mowing.
• Installation: Moderate difficulty—requires removing deck, belt, blade, and pulley. Use a puller for stubborn spindles; don’t hammer.
• Gotcha: The included bearings are pre-greased and sealed. Grease fittings are absent—if your old spindle had one, you’ll need to replace more often.
• Common issue: Check the pulley alignment after install—misalignment causes belt wear and vibration.

Should You Buy It

If you need a direct-fit, affordable replacement for a worn spindle on an MTD 46-inch deck from 1997 or newer, this is a solid choice. The price and high rating reflect good value for residential use. Skip it if you have a different deck size, need a genuine OEM part, or are doing heavy commercial work—opt for a heavier-duty spindle instead.