2 Pack 1-633109 Idler Pulley Replaces 126-7685, 132-9424, 116-4667, 126-4667, 633109, 539102610, 78-011 for Exmark Lazer Z Idler Pulley Exmark 60 inch Deck Pulley Toro Z400 Z500 Z Master Decks

What It Is

This is a 2-pack of aftermarket idler pulleys designed to replace worn pulleys on the spindle belt tensioning system of Exmark Lazer Z and Toro Z-Master zero-turn mowers with 60-inch decks. It keeps the deck belt properly tensioned to prevent slipping and ensure consistent blade speed.

Fitment & Compatibility

Before buying, confirm your mower deck is 60 inches and your model is among these:

• Exmark: Lazer Z (all series with 60" deck)
• Toro: Z400, Z500, Z Master (60" decks)
• OEM cross-references: 1-633109, 126-7685, 132-9424, 116-4667, 126-4667, 633109, 539102610, 78-011

Measure your existing pulley: outside diameter should be 4 inches, bore size 5/8 inch, with a sealed ball bearing. If your pulley is 3.5" or 4.5", this won’t fit. Also verify you have two pulleys to replace—some decks use one idler and one tensioner pulley with different specs.

Key Things to Know

• Quality: These are aftermarket, not OEM Toro/Exmark. Expect durable steel construction with sealed bearings, but finish may be less refined than originals.
• Installation: Easy—remove belt, unbolt old pulley (usually a single center bolt), install new one, and re-tension belt. No special tools needed beyond a socket wrench.
• Gotcha: The bearing is pre-sealed and non-serviceable. If it fails early, you’ll need to replace the whole pulley.
• Common issue: Some users report the pulley runs slightly noisier than OEM, but this doesn’t affect performance. Check belt alignment after install—misalignment causes rapid wear.

Should You Buy It

Buy this if you have a 60-inch Exmark Lazer Z or Toro Z400/Z500/Z Master and want a cost-effective, quick fix for a worn or noisy idler pulley. It’s a solid value for DIY maintenance, but if you need absolute OEM fit and silence, stick with genuine Toro/Exmark parts.