GT37419 GT79267 Transmission RT400 Variaton Belt Compatible with John Deere Lawn Tractor D105 E100 X105 X106 Replace AUC13704 MIA12479 GT37419 GT79267 Transmission Belt

What It Is

This is an aftermarket replacement transmission belt (RT400 Variation) for John Deere lawn tractors, designed to transfer power from the engine to the hydrostatic transaxle. It’s used on select D100/E100/X100 series models with 42-inch or 48-inch decks.

Fitment & Compatibility

Before buying, confirm your model and deck size. This belt fits John Deere D105, D110, D125, D130, E100, E110, E120, E130, X105, X106, X110, X120, X125, X126, X140, and X145 with 42-inch or 48-inch decks. OEM cross-references include GT37419, GT79267, AUC13704, and MIA12479. Measure your old belt—this one is a 5/8-inch wide, 92.5-inch outer circumference belt (Kevlar-reinforced). If your tractor uses a different deck size (e.g., 54-inch) or has a variator pulley system, it won’t fit. Check your model’s serial number against John Deere’s parts catalog to be safe.

Key Things to Know

• Quality: Aftermarket belt, not OEM. Users report it works well for light-to-moderate mowing, but may wear faster than a John Deere-branded belt under heavy use or dusty conditions.
• Installation: Moderate difficulty—requires removing the mower deck and routing the belt around the transmission pulley and variator. A belt tensioner tool helps; a wrench and screwdriver are usually enough.
• Common gotcha: The belt can slip if the variator pulley is worn or misaligned. Inspect the pulley for grooves or rust before installing. Also, check your deck’s idler pulley—if it’s seized, the belt will chirp or snap quickly.
• No returns on used belts: Once installed and run, most sellers won’t accept returns. Measure twice, buy once.

Should You Buy It

If you need a budget-friendly replacement for a standard 42/48-inch deck John Deere tractor and are comfortable with a DIY installation, this belt is a good value. Skip it if you’re a heavy user or want OEM longevity—spend more on a John Deere or Gates belt for commercial-grade duty.