AM135526 Idler Pulley Compatible with John Deere Ztrak Z355E Z245 X310 Z425 X324 X330 X350 Z435 Z445, Replacement Lawn Mower Deck Idler Pulley for Riding Mower & Zero Turn Tractor

What It Is

This AM135526 idler pulley is a replacement part for the mower deck belt tensioning system on select John Deere Ztrak zero-turn and X-series riding mowers. It keeps the deck belt tight and aligned so the blades spin properly.

Fitment & Compatibility

Before buying, confirm your mower model and deck size. This pulley fits John Deere Ztrak Z355E, Z245, Z435, Z445 and X-series X310, X324, X325, X330, X350. It also works on X320, X340, X360, X380, X394, X485, X495, X585, X595, and X720. Check your deck number (typically 48-inch or 54-inch for these models). Measure the pulley diameter—should be 4.0 inches outside diameter with a 5/8-inch bore. Verify your OEM part number matches AM135526 or the cross-referenced OEM numbers (M132465, M154928, M167448, AM137410). If your machine uses a different pulley size or bore, this won’t fit.

Key Things to Know

• Build quality: This is an aftermarket part with a metal pulley and sealed bearing. It’s comparable to OEM but not identical—check for smooth spin and no wobble before install.
• Installation difficulty: Easy. Remove the old pulley (one bolt), clean the spindle, and bolt the new one on. Tighten to 30-40 ft-lbs. No special tools needed.
• Common gotcha: The bearing is pre-lubricated and sealed—do not add grease. Over-tightening the bolt can warp the pulley flange.
• Belt alignment: If your deck belt was squealing or slipping, this pulley is often the culprit. Replace it in pairs if the other idler pulley shows wear.

Should You Buy It

If you own one of the listed John Deere models and need a budget-friendly, functional replacement for a worn or noisy idler pulley, this is a solid choice. It’s not OEM, but the 4.8-star rating and metal construction suggest it holds up well for the price. Skip it if you want a factory part or need a different bore size.