Youxmoto Spindle Assembly for 46" Mower Decks — Replaces MTD 618-06989/918-06989, 174.2mm Height & 159mm Pulley

Youxmoto 618-06989 / 918-06989 is a direct-fit spindle assembly engineered to replace worn spindles on 46" lawn mower decks used by Troy-Bilt, MTD and related models.

When a mower deck starts producing uneven cuts, loud bearing noise, or excessive vibration, the spindle assembly is often the root cause. This replacement spindle is dimensioned and drilled to match factory specifications—174.2 mm overall height and a 159 mm pulley outer diameter—so it restores deck geometry and blade alignment without machine modification. It’s sold as a complete assembly for straightforward swap-in service on a long list of compatible model numbers.

Which mower models will this spindle assembly fit?

The Youxmoto spindle is made to match MTD and Troy-Bilt 46" deck applications across many production variants. It lists compatibility by reference numbers and common model families so you can confirm fit by cross-referencing your machine’s part number or service manual.

• Replaces MTD part numbers 618-06989 and 918-06989.
• Fits MTD models such as T1500, T1600, T1700, T1900, T2600, T2700, LT4600 and CLT46CVT variants.
• Compatible with Troy-Bilt and Horse series bronco/horse 46 models, including TB46 and Bronco 46 variants.
• Match by service code or stamped part number for final confirmation.

How do the spindle’s measurements matter when replacing a worn unit?

Correct dimensions ensure the blade sits at the original radius and the belt alignment remains true. This Youxmoto assembly duplicates critical sizes so pulley alignment, blade height and belt tracking behave like new parts did from the factory.

• Overall height: 174.2 mm (6 6/7 inches) to preserve deck clearance and blade geometry.
• Pulley outer diameter: 159 mm (6 1/4 inches) for correct belt wrap and tension.
• Center mounting: 6-point star center hole matching the OEM interface for secure fitment.

What performance and service benefits can I expect after installing this spindle?

Replacing a failing spindle typically reduces vibration, restores a level cut, and stops bearing noise. Because the assembly arrives preassembled, it reduces installation steps and lets you get the deck back into service faster.

• Reduces blade wobble and returns an even, professionally trimmed swath.
• Stops grinding or rumbling caused by worn bearings or shaft play.
• Preassembled unit simplifies installation—no separate bearing or housing press-fit required.

Are there installation notes or compatibility checks I should perform?

Before installing, compare your original spindle’s overall height, pulley diameter and mounting hole pattern to the replacement. Also inspect blade bolts, belt condition and deck spindle mounts for wear to avoid premature failure of the new unit.

• Verify part numbers 618-06989 or 918-06989 on the old spindle or mower parts diagram.
• Compare the 174.2 mm height and 159 mm pulley diameter to your original spindle.
• Replace worn belts and blades at the same time for best cutting results.

Who is this for? This Youxmoto spindle assembly is aimed at owners and technicians of 46" deck lawn tractors from MTD, Troy-Bilt and related brands who need a direct replacement for a failing spindle. It suits DIYers comfortable with basic deck removal and bolt torque work, as well as repair shops that require a dependable OEM-equivalent assembly to restore smooth, level cutting performance without modifying the deck.