HD Switch Deck Belt Pulley Idler Arm Tensioner Bushing & Hardware Kit fits John Deere LX280 LX289 G100 GT225 GT235 GT235E GT242 GT245 GT262 GT275 GX255 GX325 GX335 GX345 GX355 SST18 X324 Lawn Mower

What It Is

This is a replacement bushing and hardware kit for the idler arm tensioner on the deck belt pulley system. It keeps the belt tight and aligned during mowing, preventing slippage and premature belt wear on select John Deere lawn tractors and garden tractors.

Fitment & Compatibility

Check your deck size (typically 48-inch or 54-inch) and model series before buying. Fits John Deere LX280, LX289, G100, GT225, GT235, GT235E, GT242, GT245, GT262, GT275, GX255, GX325, GX335, GX345, GX355, SST18, and X324. Cross-references OEM part numbers M139117, M159117, and AM137335. Measure the idler arm bushing bore (0.5-inch ID) and hardware bolt length (1.25-inch) to confirm match—some later X300 series use a different size. Verify your deck has the spring-loaded tensioner arm, not a fixed pulley.

Key Things to Know

• Quality: HD-brand kit uses sintered bronze bushing and grade 8 hardware—holds up better than cheap plastic or zinc alternatives. Some users report the bushing is slightly undersized; lightly sand the idler arm shaft if it binds.
• Installation: Moderate difficulty (30-45 minutes). You’ll need a socket set, breaker bar, and penetrating oil for rusted bolts. The tensioner spring can be tricky to reattach—use a spring puller or zip tie to hold it.
• Common gotcha: The included bolt may be too short for decks with thick weld-nuts. Test fit before reassembling the belt. Also, check the idler pulley bearing while you’re in there—if it’s rough, replace it separately.
• Wear signs: Squeaking, belt wobble, or uneven deck belt wear usually means this bushing is shot. Replace both bushings if your deck has two idler arms.

Should You Buy It

If your John Deere mower has a loose or noisy deck belt tensioner and you want a budget-friendly fix with decent hardware, this kit works well for most 48-54 inch decks. Avoid it if you need a full pulley assembly or have an older deck with non-standard bolt spacing—buy OEM instead.