8TEN Idler Pulley for John Deere Z930M Z950R Z915E Z955M Z920M Z930R Z950M Z930A Z925A Z960R Z950A Z720A Ztrak AUC11584

What It Is

This is a replacement idler pulley for the mower deck spindle drive belt on select John Deere ZTrak zero-turn mowers. It keeps the belt tensioned and aligned so the blades engage and spin properly.

Fitment & Compatibility

Before buying, verify:

• OEM cross-reference: Replaces John Deere part #AUC11584 (also fits #M155242, #M156508).
• Exact model list: Fits Z930M, Z950R, Z915E, Z955M, Z920M, Z930R, Z950M, Z930A, Z925A, Z960R, Z950A, Z720A, and Ztrak series. Does not fit older Z700 or Z800 series without checking pulley diameter.
• Measurements: Pulley diameter is 3.5 inches; shaft hole is 1/2 inch (12.7mm) with a 5/8 inch (15.9mm) bearing depth. Measure your old pulley’s O.D. and shaft bore to confirm.
• Deck size: Works on 48", 54", and 60" decks on these models—but double-check your deck’s belt routing diagram, as some use two idlers.

Key Things to Know

• Quality vs OEM: Aftermarket 8TEN is built with a sealed bearing and metal hub. It’s comparable to OEM but costs about half. No known premature wear issues in reviews.
• Installation difficulty: Easy (15–20 minutes). You only need a socket or wrench to remove the center bolt. No special tools.
• Common gotcha: The pulley’s flat face may be slightly thicker than OEM. If your belt rubs the deck housing, you may need a thin washer as a spacer under the mounting bolt.
• Belt condition check: Always inspect the belt for cracks or glazing when replacing the pulley—a worn belt can quickly ruin a new pulley.

Should You Buy It

If you own one of the listed ZTrak models and need a reliable idler pulley without paying dealer prices, this 8TEN unit is a solid choice. It’s well-reviewed, fits accurately, and installs easily. Skip it only if you prefer OEM-only parts or have an older ZTrak model not listed—measure first to avoid a return.