AM136327 Mower Deck Gage Wheel Arm Right Front or Left Rear 3/4" Dia. for John Deere X300, X304, X310, X320, X324, X340, X360, X500, X530, X534, X540, 570, X590, 48In & 54In Mower Decks

What It Is

The AM136327 is a deck gauge wheel arm that supports the outer edge of a John Deere mower deck, preventing scalping and ensuring a consistent cut height. It’s designed for the right front or left rear position on 48-inch and 54-inch mower decks used with select X300 and X500 series lawn tractors.

Fitment & Compatibility

• Deck size: Fits only 48-inch (48C, 48M) and 54-inch (54C, 54M) decks. Not for 42-inch or 60-inch decks.
• Models: Compatible with John Deere X300, X304, X310, X320, X324, X340, X360, X500, X530, X534, X540, 570, X590.
• Position: Right front or left rear. The arm uses a 3/4-inch diameter pivot pin—verify your deck’s pin size before ordering (some older decks use 5/8-inch pins).
• OEM vs aftermarket: This is an OEM John Deere part (AM136327). Aftermarket copies may have looser tolerances or thinner metal; check reviews if going non-OEM.
• What to measure: Confirm the arm length (approx. 7 inches from pivot center to wheel center) and the bracket hole diameter (3/4 inch). If your existing arm is bent or cracked, match the bend angle.

Key Things to Know

• Installation difficulty: Easy—swap takes 10–20 minutes with a socket set and possibly a pry bar to align the pin. No special tools required.
• Common gotcha: The pin can rust or seize in the bracket. Soak with penetrating oil (e.g., WD-40 Specialist) before removal. If the bracket is worn, the arm may wobble—replace the bracket too.
• Quality note: OEM steel construction is durable, but the plastic wheel may crack from heavy use or hitting obstacles. Check the wheel separately (part AM137333) if the wheel is damaged.
• Pairing: If one arm is worn, the opposite side often is too. Consider replacing both arms on the same axle to maintain even deck height.

Should You Buy It

If you own a compatible John Deere X300 or X500 series with a 48- or 54-inch deck and need a direct OEM replacement for a worn or bent gauge wheel arm, this is a solid, affordable choice. It’s not for other brands or deck sizes, and you’ll get the best result by checking pin diameter and bracket condition first. For light-duty residential mowing, it’ll last several seasons; for heavy commercial use, expect to replace the plastic wheel sooner.