8TEN Idler Pulley for John Deere Z335E Z335M Z345M Z345R ZTrak AUC10172 2 Pack

What It Is

This is a pair of aftermarket idler pulleys designed to replace OEM part AUC10172 on specific John Deere ZTrak zero-turn mowers. They guide and tension the deck belt, keeping it properly routed for consistent blade engagement.

Fitment & Compatibility

Check these before buying:

• Model fit: Confirmed for John Deere Z335E, Z335M, Z345M, and Z345R ZTrak mowers. Not universal—verify your model number on the mower’s ID tag.
• Deck size: Works with 42-inch and 48-inch decks on these models. Measure your deck width if unsure.
• OEM replacement: Replaces John Deere part AUC10172. If your original pulley has a different number, cross-reference before buying.
• Physical specs: Each pulley has a 3.5-inch outer diameter, a 5/8-inch bore, and a sealed ball bearing. Measure your old pulley’s diameter and bore to confirm match.
• Quantity: This is a 2-pack. If your deck uses only one idler pulley, you’ll have a spare.

Key Things to Know

• Quality note: These are aftermarket, not OEM. They use sealed bearings and a steel hub, which should last well under normal residential use. Some users report slightly less smooth spin than OEM, but still work fine.
• Installation difficulty: Easy—requires a socket wrench and basic mechanical skill. Takes about 15 minutes per pulley. No special tools needed.
• Common gotcha: The pulley bolt may be tight or thread-locked. Use a breaker bar if needed. Reinstall with medium thread locker to prevent loosening.
• Belt wear: If your belt is old or frayed, replace it at the same time. A worn belt can damage a new pulley quickly.

Should You Buy It

If you own a Z335E, Z335M, Z345M, or Z345R and need to replace a worn or noisy idler pulley, this 2-pack is a cost-effective choice. It’s a solid aftermarket alternative to OEM for residential mowing, especially if you want a spare on hand. Not ideal for heavy commercial use—go OEM if you need maximum durability.