131494 Idler Pulley Craftsman Replaces 165888 Idler Pulley Craftsman, 532173437, 532173438, 597025001, 532165888, 532173438, 173437, 173438 for Craftsman LT1000, YTH18542, LT2000 Tractors

What It Is

The 131494 idler pulley is a replacement tensioner pulley for the mower deck drive belt on select Craftsman lawn tractors. It keeps the belt tight so the blades spin properly; if it seizes or wobbles, the belt slips or throws.

Fitment & Compatibility

• Direct OEM cross: Replaces Craftsman 532165888, 532173437, 532173438, 597025001, 173437, 173438.
• Common tractor models: Craftsman LT1000, YTH18542, LT2000, and many others with 42–54 inch decks using a two-pulley belt tension system.
• What to measure before buying: Outside diameter should be 3.5 inches; bore size 0.5 inch (for a 1/2-inch shoulder bolt). Confirm your deck’s idler arm accepts a flat, flanged pulley (not a v-groove).
• Deck size check: Primarily fits 42-inch and 46-inch decks, but verify your model’s parts diagram—some 50/54-inch decks use a different pulley.

Key Things to Know

• Metal vs. plastic: This pulley has a steel bearing with a plastic outer shell. It’s fine for residential use, but heavy commercial mowing may wear it faster than an all-metal unit.
• Installation difficulty: Easy—remove the deck belt, unbolt the old pulley (usually one 1/2-inch or 5/8-inch bolt), swap, and re-tension. No special tools needed.
• Common gotcha: The inner bearing race is smooth; it must spin freely on the shoulder bolt. If the bolt is corroded or the pulley is overtightened, it will lock up. Use a light anti-seize on the bolt shaft.
• Belt compatibility check: This pulley works with belts that are 1/2-inch wide (standard A-section). If your deck uses a 3/8-inch belt, this pulley won’t match.

Should You Buy It

Yes, if your Craftsman LT1000, YTH18542, or similar tractor has a noisy or seized idler pulley on the deck. At $11.96 with a solid 4.6-star rating from hundreds of buyers, it’s a cost-effective fix for a common failure. Skip it if you need an all-metal pulley for heavy-duty commercial use.