42 inch Deck Spindle Blade Belt Rebuild Kit for John Deere L100 L105 L107 L108 L100 L110 L111 L118, Include Spindle GY20050 GY20785, 1/2" x 104" Belt GX20072 GY20570, Mulching Blade GX20249 GX20433

What It Is

This is a complete rebuild kit for the 42-inch deck spindle and blade belt system on select John Deere L-Series lawn tractors. It includes two spindle assemblies (GY20050, GY20785), a 1/2" x 104" drive belt (GX20072/GY20570), and two mulching blades (GX20249/GX20433)—everything needed to refresh the cutting deck’s rotating components in one order.

Fitment & Compatibility

Check your deck size first. This kit is only for a 42-inch deck (typically stamped “42” on the deck shell or in your owner’s manual). It fits the following John Deere models: L100, L105, L107, L108, L110, L111, L118. Do not assume it fits L120 or L130—those use a 48-inch deck with different spindles and belt lengths.

OEM cross-reference: Spindle GY20050/GY20785 replaces OEM 100 series spindles; belt GX20072/GY20570 is a direct replacement for the factory 104-inch belt; blades GX20249/GX20433 match OEM 42-inch mulching blades. The kit is aftermarket, not genuine John Deere, so verify dimensions if you have a non-standard deck or aftermarket spindles already installed.

Measurement check: Belt must be 1/2" wide by 104" long. Spindle bolt pattern is standard for these decks. Blades are 21.5 inches long (center hole to tip) with a 1-inch arbor hole.

Key Things to Know

• Installation difficulty: Moderate. You’ll need a socket set, a torque wrench (spindle nuts to 30-40 ft-lbs), and a blade removal tool. Expect 1-2 hours if you’ve done deck work before.
• Common gotcha: The belt routing is specific—check your deck diagram or watch a video for the correct path around the idler pulleys. Wrong routing causes slipping or premature wear.
• Quality note: Spindles are typically pre-greased and sealed, but some users report needing to add a small amount of grease to the fittings before installation. Blades are stamped steel, sharp out of the box.
• Mulching vs. bagging: These are mulching blades (curved, not straight). If you primarily bag clippings, consider standard lift blades instead—mulching blades don’t throw clippings as well into a bag.

Should You Buy It

If you have a 42-inch deck on a John Deere L100–L118 and your spindles are noisy, the belt is frayed, or blades are dull, this kit is a solid, cost-effective way to replace all three wear items at once. It’s less expensive than buying OEM parts individually, and the 4.5-star rating suggests reliable fit for most users. Skip it if you need a different deck size or only want to replace one component—individual parts may suit you better.