3 Pcs Idler Deck Pulley Compatible with John Deere Zero-Turn Lawn Mower Z425 Z435 Z445 with 48" 54" Deck, Flat Idler Pulley Replaces AM135526 AM128118 AM143737/AM136693

What It Is

This is a set of three flat idler pulleys designed for John Deere zero-turn mowers, specifically the Z425, Z435, and Z445 models with 48" or 54" decks. They guide and tension the deck belt, reducing vibration and ensuring proper blade engagement.

Fitment & Compatibility

Before buying, confirm your mower model and deck size (48" or 54")—these pulleys won’t fit other deck sizes or models without modification. Check your existing pulley part numbers: this set replaces OEM AM135526, AM128118, AM143737, and AM136693. Measure the center hole diameter (typically 5/8") and pulley diameter (about 4") to match your old ones. Note: these are aftermarket parts, not genuine John Deere; some users report slight differences in bearing quality or thickness.

Key Things to Know

• Quality variance: At this price point, bearings may not be sealed as well as OEM; expect shorter lifespan under heavy use or in wet conditions.
• Installation: Straightforward if you have basic tools—remove the belt, unbolt old pulleys (usually a 15/16" socket), and swap. No special skills needed.
• Common gotcha: Verify the belt routing after installation; misalignment can cause premature wear or belt slippage.
• Pack includes 3 pulleys: Ensure you need all three—some decks use only two idlers, so you’ll have a spare.

Should You Buy It

If you own a Z425, Z435, or Z445 with a 48" or 54" deck and need a budget-friendly pulley replacement, this set works for light to medium-duty use. However, if you mow commercially or in dusty/wet conditions, consider OEM pulleys for longer durability.