954-04045 754-04045 Lawn Mower Deck Belt 1/2" x 109" Replacement for MTD Cub Cadet Troy Bilt 954-04045 754-04045 42" LT1040 LT1042 RZT17 RZT42 LX426 LX423 LX425 RZT-42 Toro 112-5800

What It Is

This is a 1/2-inch wide, 109-inch long V-belt that drives the mower blades on select 42-inch MTD, Cub Cadet, Troy-Bilt, and Toro lawn tractors. It replaces OEM part numbers 954-04045, 754-04045, and Toro 112-5800.

Fitment & Compatibility

Before buying, confirm your mower has a 42-inch cutting deck and that your model is listed: Cub Cadet LT1040, LT1042, RZT17, RZT42, LX426, LX423, LX425; Troy-Bilt RZT-42; Toro models using 112-5800. Measure your old belt—it must be exactly 1/2 inch wide and 109 inches in circumference. This is an aftermarket replacement, not OEM, but matches those specs. Check your deck’s belt routing diagram (usually under the seat or in the manual) to ensure the 109-inch length matches your specific pulley configuration; some 42-inch decks use a shorter or longer belt.

Key Things to Know

• Quality: Aftermarket belt, not OEM. Many users report it works fine for normal residential use, but may wear faster than a genuine OEM belt under heavy or frequent mowing.
• Installation: Moderate difficulty. You’ll need to remove the deck or at least the belt covers, release the idler pulley tension, and route the belt around all pulleys exactly per your deck’s diagram. A wrong route causes poor blade engagement or belt slip.
• Common gotcha: Double-check that your deck uses a single 109-inch belt—some 42-inch decks (especially older or different series) require a different length. Also verify your idler pulley spring tension isn’t weak; a worn spring can cause belt slipping or premature wear.
• Warranty: Aftermarket belts typically don’t carry the same warranty as OEM. If you have a new mower under warranty, using this may void coverage.

Should You Buy It

This is a solid budget choice for DIY replacement on a residential Cub Cadet, Troy-Bilt, or Toro 42-inch mower if you’re comfortable with basic deck work and don’t need OEM durability. If you mow multiple acres weekly or want maximum belt life, spend more on an OEM belt.