q&p Outdoor Power 4-5/8" Heavy-Duty Flat Idler Replaces John Deere AM37442 AM107468 AM37249 AM37442 280-164 Fits Murray 46"-52" Decks

What It Is

The Q&P Outdoor Power 4-5/8" Heavy-Duty Flat Idler is a replacement pulley for the mower deck’s belt tensioning system. It’s designed for Murray and John Deere lawn tractors with 46" to 52" cutting decks, ensuring the drive belt stays tight during operation.

Fitment & Compatibility

Before buying, measure your existing idler pulley’s outside diameter—it must be exactly 4-5/8". This part replaces OEM John Deere numbers AM37442, AM107468, AM37249, AM37442 and Murray/MTD number 280-164. It fits Murray 46", 48", 50", and 52" decks, plus many John Deere models using those OEM numbers. Check your deck’s model number (often stamped on the underside) and confirm it uses a flat idler pulley with a 5/8" bore (common on these decks). Not for zero-turn mowers or decks smaller than 46".

Key Things to Know

• Build quality: Heavy-duty steel construction with a sealed bearing—holds up better than some OEM plastic pulleys.
• Installation difficulty: Easy (15-30 minutes) if you have a socket set and can remove the belt. No special tools required.
• Common gotcha: The pulley’s flat face must align with your belt’s flat side; if your deck uses a grooved idler, this won’t work.
• Check bearing play: Spin the pulley before installing—it should roll smoothly with no wobble or grinding.

Should You Buy It

If you need a reliable, budget-friendly replacement for a worn flat idler on a Murray 46"-52" deck or compatible John Deere model, this is a solid pick. It’s a direct fit with better durability than typical plastic pulleys, and the price is tough to beat for a heavy-duty option.