JZGRDN Rear Gage Wheel Arm AM138220 AM136329 Compatible with John Deere X500 X520 X530 X534 X540 X590 X300 X304 X320 X324 X340 X360 Tractors

What It Is

This is a replacement rear gauge wheel arm for John Deere 300 and 500 Series lawn tractors. It supports the mower deck’s rear edge, preventing scalping and uneven cuts on uneven terrain.

Fitment & Compatibility

• Deck size matters: Fits 48-inch, 54-inch, and 62-inch decks on compatible models—verify your deck type before ordering.
• Compatible models: X300, X304, X320, X324, X340, X360, X500, X520, X530, X534, X540, X590. Not for older LX or L series.
• OEM cross-reference: Replaces John Deere parts AM138220 and AM136329. Aftermarket part, not genuine JD.
• Measurement check: Arm length is roughly 9 inches from pivot center to wheel bolt hole. Measure your existing arm to confirm.
• Hardware: Includes mounting bolt and nut, but reuse your original wheel (not included) if it’s in good shape.

Key Things to Know

• Quality concerns: Low 3.2-star rating from only 5 reviews. Some users report thinner metal than OEM, which can bend under heavy use on rough ground.
• Installation: Straightforward—remove one bolt, swap arm, reinstall. Requires a socket or wrench, 10-15 minutes per side.
• Common gotcha: The paint may chip quickly, but that doesn’t affect function. Check that the pivot hole alignment matches your deck bracket—minor misalignment can cause binding.
• Price vs. OEM: At $22.20, it’s roughly half the cost of a genuine John Deere arm. Worth it if you need a budget fix, but don’t expect OEM durability.

Should You Buy It

Buy this if you have a compatible John Deere and need a quick, low-cost replacement for a bent or broken rear gauge wheel arm on a residential lawn. Skip it if you mow commercially, on very rough terrain, or want parts that match OEM build quality—spend the extra for genuine John Deere.