1-Pack GY22082 GY20629 Flat Idler Pulley - Replacement for John Deere L120 L110 LA115 D125 D170 42" Deck - Compatible with MTD 756-05034A Cub Cadet Craftsman Riding Mowers (OD: 5-1/4", H: 1-3/4")

What It Is

This is a 5-1/4" diameter, 1-3/4" tall flat idler pulley that routes and tensions the drive belt on 42" mower decks. It’s a direct replacement for the factory pulley on John Deere L120, L110, LA115, D125, D170 models, plus many MTD, Cub Cadet, and Craftsman riding mowers with a 42" stamped deck.

Fitment & Compatibility

Check your deck size: this pulley fits 42" decks only. Measure your existing pulley’s outer diameter (OD) and height. This one is 5-1/4" OD x 1-3/4" tall. It replaces OEM part numbers GY22082, GY20629 (John Deere), 756-05034A (MTD), and equivalents from Cub Cadet and Craftsman. Verify your mower’s model and deck serial number before buying—some 42" decks use a different pulley if the deck is a fabricated (fabricated) style. The pulley has a smooth flat face; if your original had a grooved or ribbed face, this won’t work.

Key Things to Know

• Build quality: This is an aftermarket pulley with a sealed ball bearing and steel construction. It’s comparable to OEM for less money, but not identical—some users report slightly thinner steel.
• Installation: Easy swap—remove the belt, unbolt the old pulley (usually a 5/16" or 3/8" bolt), install the new one, and re-route the belt. No special tools needed.
• Common gotcha: The center hole diameter is 3/8". If your mower uses a 1/2" bolt or a different shoulder design, this won’t fit. Also, if your old pulley had a spacer or bushing, you may need to reuse it.
• Belt tension: After installing, check belt tension. A worn pulley can cause slipping or belt wear even if the new pulley is correct.

Should You Buy It

If you have a 42" deck on a John Deere, MTD, Cub Cadet, or Craftsman riding mower and need a quick, affordable fix for a worn or noisy idler pulley, this is a solid choice. The price is right, the rating is excellent, and installation is straightforward for anyone comfortable with basic tools. Skip it if your deck is larger than 42" or if you need an exact OEM match for warranty or precision fit.