GX20072 42 inch Mower Deck Belt 1/2" X 104" Compatible with John Deere D100 D105 D110 D120 D125 D130 L100 L110 E110 E120 E100 Sabre GY20570 LA100 LA105 LA110 LA120 LA125 LA135 Deck Belt

What It Is

This is a replacement drive belt for 42-inch cutting decks on select John Deere and Sabre lawn tractors. It connects the engine pulley to the blade spindles, making the blades spin for cutting grass. It’s a standard maintenance part for residential mowers with 42-inch decks.

Fitment & Compatibility

Before buying, check your mower’s model number and deck size. This belt fits John Deere D100, D105, D110, D120, D125, D130, L100, L110, E100, E110, E120, and Sabre models LA100, LA105, LA110, LA120, LA125, LA135. It also replaces OEM part GY20570. The belt is 1/2 inch wide and 104 inches long—measure your old belt’s length and width to confirm. It’s aftermarket, not John Deere OEM, so it may not have the same rubber compound or wear life. Verify your deck is exactly 42 inches (some models have 38 or 48 inch decks that use different belts).

Key Things to Know

• Quality: Rated 4.6/5 from 291 reviews, but aftermarket belts can stretch more than OEM. Expect 1-2 seasons of heavy use.
• Installation: Moderate difficulty—you’ll need to remove the deck or at least the belt guard. Route the belt around pulleys per your mower’s diagram (check your manual or online). No special tools required.
• Common gotcha: The belt may be slightly tight on first install. Run the deck at low speed for a few minutes to seat it. If it squeals or slips, recheck routing—improper tension is the most common issue.
• Price: At $13.88, it’s roughly half the cost of OEM belts. Good value if you’re on a budget, but expect to replace it sooner.

Should You Buy It

If you own a compatible John Deere or Sabre 42-inch deck tractor and need a low-cost replacement for a worn or broken belt, this is a solid choice. It’s not for heavy commercial use or if you want OEM longevity, but for most homeowners mowing a standard yard, it works fine. Just double-check your deck size and belt measurements before ordering.