173437 173438 Flat Idler Pulley, Replacement for Husqvarna, John Deere, Craftsman 42" 44" Lawn Mower Decks (OD 3-7/8"), Replace 532173437 532173438 131494 532131494 104360X AM103480 AM37321, 1 Pack

What It Is

This is a flat idler pulley (3-7/8" outer diameter) that guides and tensions the mower deck belt on 42" and 44" lawn tractors. It’s used on Husqvarna, John Deere, and Craftsman models to keep the belt tracking properly during cutting.

Fitment & Compatibility

Before buying, confirm these three things:

• Deck size: Fits 42" and 44" decks only (not 46" or 48").
• OEM cross-references: Replaces Husqvarna 532173437, 532173438, 131494, 532131494, and John Deere AM103480, AM37321, plus 104360X.
• Measurement: Outer diameter is exactly 3-7/8" (98.4mm). Measure your old pulley’s OD to verify. The center hole is 1/2" (12.7mm) – check your spindle bolt size.
• Brand note: This is an aftermarket part, not OEM. It fits many Craftsman, Husqvarna, and John Deere tractors, but always verify your model number against the cross-reference list.

Key Things to Know

• Quality: Metal construction with a sealed bearing. Good for the price, but may not last as long as OEM if used in heavy commercial duty.
• Installation: Easy – remove the bolt holding the old pulley, swap it, and re-torque. No special tools needed.
• Gotcha: The pulley is flat, not grooved. If your deck uses a V-belt, this won’t work. Check your belt type first.
• Bearing noise: A small percentage of users report bearing noise after a season. Inspect the pulley for wobble during install.

Should You Buy It

If you need a quick, affordable replacement for a worn idler pulley on a 42" or 44" residential mower deck from Husqvarna, John Deere, or Craftsman, this is a solid budget pick. Just verify your deck size and bolt hole before ordering. Not for commercial use or odd-size decks.