AM143737 Idler Pulley AM136693 Compatible with John Deere Z225 Z235 Z245 Z255 Z355E Z445 Z425 Z435 LT190 Lawn Tractor Replace AM143737 AM136693 Idler Pulley

What It Is

This is a replacement idler pulley (models AM143737 / AM136693) that guides and tensions the mower deck belt on select John Deere zero-turn and lawn tractors. It’s used on the spindle assembly to keep belt alignment and reduce vibration during cutting.

Fitment & Compatibility

Direct OEM replacements: AM143737 and AM136693.
Fits these John Deere models: Z225, Z235, Z245, Z255, Z355E, Z445, Z425, Z435, LT190 (verify your deck size – typically 42” to 54”).
What to check before buying:

• Measure your old pulley’s outer diameter (this one is ~4”).
• Confirm belt width (usually 1/2” or 5/8” – check your deck manual).
• Inspect the bearing type (this uses a sealed ball bearing – no maintenance needed).
• Aftermarket vs. OEM: This is a non-OEM part; quality may vary. Verify bolt hole pattern (center hole is typically 5/8”).

Key Things to Know

• Quality: Sealed bearing reduces debris ingress, but aftermarket pulleys may have shorter lifespan than OEM.
• Installation: Moderate difficulty – requires removing belt, old pulley, and installing with a wrench. No special tools needed.
• Common gotchas:
  • Belt routing must match original – misalignment causes premature wear.
  • Check pulley for wobble after install – indicates bent shaft or loose bolt.
  • If your old pulley has a plastic body vs. this metal one, ensure deck clearance (metal is more durable but slightly heavier).
• Cost vs. OEM: At ~$17, it’s a fraction of OEM price; good for budget repairs but may need replacement sooner.

Should You Buy It

Buy this if you need a quick, low-cost fix for a worn idler pulley on a compatible John Deere mower and are comfortable with basic mechanical work. It’s a solid value for light-to-medium use, but heavy-duty operators or those wanting maximum longevity should consider an OEM part for better bearing durability.