Pro Parts Place, PPP OEM SPEC Made Belt Compatible with John Deere GX25628 Z335E Z335M Z345M Z345R with 42" Deck

What It Is

This is a replacement drive belt for select John Deere Z300-series zero-turn mowers with a 42-inch deck. It transfers power from the engine pulley to the mower deck blades, enabling cutting operation.

Fitment & Compatibility

Before buying, confirm your mower model is listed: John Deere Z335E, Z335M, Z345M, Z345R—all with the 42-inch deck only. The belt replaces OEM part GX25628. Measure your existing belt’s length (OEM spec is 149.5 inches) and width (typically 1/2 inch). If your deck is 48 or 54 inches, this belt will not fit. Check your mower’s serial number against John Deere’s compatibility chart; some early production units may differ slightly.

Key Things to Know

• Quality: Pro Parts Place “OEM Spec” belts are aftermarket but made to OEM tolerances. Expect similar lifespan to OEM if deck spindles and pulleys are in good condition.
• Installation difficulty: Moderate. You’ll need to remove the belt guard and release tension from the idler pulley. A belt routing diagram is helpful—take a photo before removal.
• Common gotchas: Worn deck spindles or seized pulleys will shred any belt quickly. Inspect and replace those first. The belt may feel slightly stiff out of the box; it will loosen after a few minutes of use.
• No pulley included: This is just the belt. If your pulleys are worn, replace them separately.

Should You Buy It

If you own a John Deere Z335E, Z335M, Z345M, or Z345R with a 42-inch deck and want a reliable, affordable alternative to the $30+ OEM belt, this is a solid choice. It’s not for other deck sizes or models. For best results, confirm your existing belt is 149.5 inches and inspect your deck’s pulleys and spindles before installing.