Deck Idler Arm Ternsioner & Bushing Rebuild Kit for John Deere 48C 54C GT LX GX Scotts Sabre Tractor Lawn Mowers Used with AM37249 Pulley, Replace for M143350 M111358 M131119 24H1184 T40189 M122350

What It Is

This deck idler arm tensioner and bushing rebuild kit replaces the worn-out pivot assembly that keeps the mower belt tight on John Deere 48C and 54C decks. It’s designed for use with the AM37249 pulley and fits GT, LX, GX, Scotts, and Sabre lawn tractors.

Fitment & Compatibility

Before buying, confirm your deck model (48C or 54C) and tractor series (GT, LX, GX, Scotts, Sabre). This kit replaces OEM part numbers M143350, M111358, M131119, 24H1184, T40189, and M122350. It works with the AM37249 pulley (sold separately). Measure the idler arm bolt hole spacing and bushing inner diameter—common sizes are 1/2” and 5/8”. Check that your deck uses a spring-loaded tensioner, not a fixed or manual-adjust type. If your mower has a 42-inch deck or a different arm geometry, this likely won’t fit.

Key Things to Know

• Quality: The bushing is often nylon or sintered bronze—nylon holds up better in dirty conditions. Inspect the included hardware; some kits use softer bolts that may strip.
• Installation: Moderate difficulty—requires removing the deck, belt, and pulley. A socket set and penetrating oil are helpful for rusted bolts. Expect 30–60 minutes.
• Common gotchas: The tensioner arm may be seized onto the old bushing—soak with PB Blaster before prying. The new bushing must be pressed or tapped in square; misalignment will cause belt squeal or rapid wear.
• Belt routing: After installing, double-check belt tension and routing per your manual. A loose belt will slip; overtightening can damage the new bushing.

Should You Buy It

If you have a John Deere 48C or 54C deck with a worn, wobbly idler arm and want a budget-friendly rebuild over a full arm replacement, this kit is a solid choice. It’s not for heavy commercial use—stick with OEM if you mow daily—but for home owners and light-duty mowing, it saves money and restores tension reliably.