2 Pack Pre-Greased GY21098 Spindle Assembly with GX20367 Pulley Replace John Deere AUC15811, GY20454 for John Deere D100 D105 D110 D125 D130 E100 E110 E120 E130 LA105 LA115 LA135 S100 Mowers

What It Is

This is a pre-assembled, pre-greased spindle assembly (with pulley) for 42-inch and 48-inch stamped-steel mower decks on select John Deere 100-series, LA-series, and S100 lawn tractors. It replaces the OEM part that drives the blade, and comes as a ready-to-bolt-on 2-pack with pulleys included.

Fitment & Compatibility

Before buying, confirm your deck size—this fits only 42-inch and 48-inch decks, not 54-inch or 38-inch. Compatible models include D100, D105, D110, D125, D130, E100, E110, E120, E130, LA105, LA115, LA135, and S100. It replaces OEM numbers AUC15811, GY20454, GY21098, and GX20367. Measure your spindle shaft diameter (typically 5/8-inch) and bolt pattern (2.75-inch center-to-center) to verify. This is an aftermarket part, not John Deere genuine—check that the pulley groove width matches your belt (usually 1/2-inch).

Key Things to Know

• Pre-greased and pre-assembled: No need to pack bearings or press pulleys—just unbolt the old spindle, bolt this on, and torque to spec (typically 35-45 ft-lbs).
• Quality varies: Some users report bearing noise after a season; consider adding extra grease via the zerk fitting if equipped. Inspect the pulley for wobble before installation.
• Installation tip: Remove the blade first, then the spindle bolts from below deck. A impact wrench helps, but hand tools work. Watch for stripped bolts on older decks.
• Deck compatibility: Not for zero-turn or X300-series mowers—double-check deck part number if unsure.

Should You Buy It

This 2-pack is a solid value if you need to replace both spindles on a 42- or 48-inch John Deere 100-series deck and want a quick, no-fuss swap. It’s not the most premium option, but for the price and convenience, it’s a good bet for DIY maintenance on a residential mower. Skip it if you need a single spindle, a different deck size, or a heavy-duty commercial replacement.