Threlaco 405143 1/2'' x 105-3/4" Deck Belt Replacement Lawn Mower Belt Black Tractor Belts Fit for 46" Riding Mower Parts and Accessories, Mower Replace OEM 405143 584453101 7133156 532405143 21546607

What It Is

The Threlaco 405143 is a replacement deck belt for 46-inch riding lawn mowers, designed to transfer power from the engine pulley to the mower deck spindles, driving the blades for cutting grass.

Fitment & Compatibility

Before buying, verify three things: your mower has a 46-inch cutting deck, the belt measures exactly 1/2 inch wide by 105-3/4 inches long, and your OEM part number matches one of these: 405143, 584453101, 7133156, 532405143, or 21546607. This belt commonly fits MTD, Troy-Bilt, Cub Cadet, Craftsman, and Yard Machines models with 46-inch decks—but not all. Measure your old belt’s length (lay it flat, not stretched) and confirm the belt routing diagram on your deck matches this belt’s path. If your mower has a manual tensioner vs. spring-loaded, it still works, but check pulley diameters (typically 4-5 inches) are standard.

Key Things to Know

• Quality vs. OEM: At $8.99, this is a budget aftermarket belt. It may wear faster than a Gates or OEM belt, especially on heavy-use or commercial mowers. Expect 1-2 seasons with light residential use.
• Installation: Easy DIY job (10-20 minutes). Remove the deck or use a belt routing diagram (search online by your model number). Use a wrench to release tension on the idler pulley—don’t pry the belt on.
• Common gotcha: Belt length can vary slightly (105-3/4" vs. 105.5"). If your old belt was tight, this might feel slightly looser, causing slippage or poor blade engagement. Check for proper tension after install.
• Return policy: Low rating (3.8/18 reviews) hints at occasional fitment issues. Buy from a seller with free returns, and keep your old belt until the new one is confirmed working.

Should You Buy It

Buy this belt if you need a low-cost, quick fix for a residential 46-inch mower and you’ve confirmed your OEM number matches. Skip it if you mow frequently (weekly), have a commercial mower, or want maximum durability—spend $15-20 on a Gates or OEM belt for longer life. For occasional use, this is a fine budget option.