GX20072 Mower Deck Belt for John Deere D100 D105 D110 D125 D130 L100 L110 E100 E110 E120 E130 LA105 LA110 LA115 LA135 L1742 S100 1642HS 1742HS S100 GY20570 104 inches

What It Is

The GX20072 is a 104-inch V-belt that drives the mower blades on select John Deere lawn tractors. It replaces OEM part GY20570 and is designed for 42-inch and 48-inch cutting decks used on residential models like the D100, L100, E100, and S100 series.

Fitment & Compatibility

Before buying, confirm three things: your mower model, deck size, and current belt length. This belt fits John Deere models D100, D105, D110, D125, D130, L100, L110, E100, E110, E120, E130, LA105, LA110, LA115, LA135, L1742, S100, 1642HS, 1742HS, and S100. It is not compatible with 54-inch decks or zero-turn mowers. Measure your existing belt end-to-end (flat, not stretched) – it must be exactly 104 inches. OEM part GY20570 is the direct match; this is an aftermarket replacement. Check your owner’s manual for deck size (look for “42” or “48” on the deck sticker).

Key Things to Know

• Quality: At $15.99, this is a budget aftermarket belt. Expect ~1-2 seasons of use under normal residential mowing. OEM belts (GY20570) often last longer but cost 2-3x more.
• Installation: Moderate difficulty. You’ll need to remove the mower deck, release the tensioner, and route the belt around all pulleys exactly as diagrammed. Snap a photo before removal.
• Common gotcha: The belt may feel slightly tight initially. If it won’t seat, check that the tensioner arm moves freely and the pulleys are clean. Do not force it – a misrouted belt can slip or break immediately.
• Deck size matters: This belt is for 42-inch and 48-inch decks only. Using it on a 54-inch deck will cause poor engagement and rapid wear.

Should You Buy It

If you have a compatible John Deere model with a 42-inch or 48-inch deck and need a budget-friendly replacement for light-duty residential mowing, this belt is a solid choice. Skip it if you mow heavy grass, have a 54-inch deck, or want OEM durability for heavy use.