GY21098 Spindle Assembly with GX20367 Pulley Replaces John Deere GY21098 Spindle, AUC15811 Spindle GY20962,GY20454 for John Deere D110 Spindle, D130, E100 D105, D120, Mowers(2Pack)

What It Is

This is a replacement spindle assembly (with pulley pre-installed) for the cutting deck on select John Deere lawn tractors. It houses the bearing and pulley that drive a single mower blade, and is sold as a 2-pack for dual-spindle decks.

Fitment & Compatibility

Before buying, confirm your mower deck size (typically 42-inch or 48-inch) and model. This assembly replaces OEM John Deere part numbers GY21098, AUC15811, GY20962, and GY20454. It fits these specific John Deere models: D100 series (D105, D110, D120, D130) and E100 series (E100, E120, E130). It will not fit D140, D150, D160, D170, or X300 series tractors. Measure your existing spindle housing height and pulley diameter (roughly 4.5-inch pulley) to verify physical match. This is an aftermarket part, not genuine John Deere, so check bolt pattern (three bolts, typically 3-inch spacing) and shaft diameter (1 inch) against your deck.

Key Things to Know

• Quality: Aftermarket spindle; bearings may have shorter lifespan than OEM. Grease fittings are present—grease before first use and every 10 hours.
• Installation: Moderate DIY job. You’ll need a socket set, impact wrench helpful, and a jack to lift the deck. Mark blade orientation before removal. Torque spindle bolts to 30-35 ft-lbs.
• Common Gotchas: The pulley is pre-installed but can loosen during shipping—check and tighten if needed. Deck belt routing may change with new spindle height; compare old vs. new assembly side-by-side.
• Single vs. Dual: This 2-pack covers both spindles on a dual-blade deck. If you only need one, check for single-pack options.

Should You Buy It

This is a solid, budget-friendly option if you’re handy and need to replace both spindles on a D100 or E100 series mower with a 42- or 48-inch deck. It’s not for heavy commercial use or older models outside the listed range. If you prefer genuine John Deere parts or have a high-hour mower (500+ hours), consider OEM spindles for longer bearing life.