GY21098 Spindle Assembly with GX20367 Pulley Replaces AUC15811 GY20454 GY20867 GY20962 for John Deere D100 D105 D110 D125 D130 E100 E110 E120 E130 LA105 LA110 LA115 LA120 LA135 S100 Tractors

What It Is

This is a replacement spindle assembly (GY21098) with a pre-installed GX20367 pulley, designed for 42-inch and 48-inch Edge, EZtrak, and Select Series mower decks on John Deere lawn tractors. It drives the mower blade and is a direct swap for worn or damaged original spindles.

Fitment & Compatibility

• Confirmed fit: John Deere D100–D130, E100–E130, LA105–LA135, S100 series (check your deck size—mostly 42" and 48" decks).
• Replaces OEM numbers: AUC15811, GY20454, GY20867, GY20962. If your original has any of these, this part fits.
• What to measure: The pulley diameter is 4.5 inches (114 mm), and the spindle shaft is 5/8 inch (16 mm) with two 3/8-inch mounting bolt holes spaced 3.25 inches center-to-center. Verify your deck’s bolt pattern and pulley clearance before ordering.
• Note: This is an aftermarket part, not genuine John Deere. It may use a different grease fitting or seal than OEM—check that the pulley alignment matches your belt routing.

Key Things to Know

• Quality: Mixed reviews—some report early bearing noise or seal failure after 1–2 seasons. Inspect the pulley for wobble upon arrival.
• Installation: Moderate difficulty (1–2 hours). You’ll need a jack, socket set, and possibly a puller for the old spindle. The pulley comes pre-installed, so no extra assembly.
• Common gotchas: The mounting bolts are 3/8-inch; don’t overtighten or you’ll warp the deck. Also, ensure the blade is installed with the correct orientation (sharp edge leading).
• Warranty: Typically 30-day return, but no long-term guarantee. Keep your receipt and test-run it before full use.

Should You Buy It

Buy if you need a budget-friendly, drop-in replacement for a worn spindle on a John Deere 42” or 48” deck and are comfortable with basic mechanical work. Skip it if you want OEM durability or have a deck with unusual bolt spacing—then go with a genuine John Deere spindle for higher reliability.