CUB CADET 631-08155 Fabricated 42" Mulch Plug 19A30054100 42" Xtreme S Mulch Kit

What It Is

The CUB CADET 631-08155 is a fabricated steel mulch plug designed to block the discharge chute on 42-inch Xtreme S-series mower decks, converting side-discharge mowers into mulching machines that recut clippings for lawn nutrient recycling.

Fitment & Compatibility

Before buying, confirm you have a Cub Cadet Xtreme S-series mower with a 42-inch fabricated deck (model numbers typically start with 19A30054100). This plug is OEM-specific and will not fit stamped decks or other brands. Measure your deck’s discharge opening width and compare to the plug’s dimensions (roughly 42-inch deck width). Check your mower’s model number against the 631-08155 OEM part listing—compatible with XT1, XT2, and XT3 Enduro Series with 42-inch fabricated decks, but not the 42-inch stamped deck variants.

Key Things to Know

• Quality: Fabricated steel construction is more durable than plastic plugs, but some users report fitment is tight—may require minor filing or adjustment for a perfect seal.
• Installation: Typically bolts directly to the deck’s discharge opening with included hardware; expect 15–30 minutes with basic hand tools. No welding or cutting needed.
• Common gotcha: The plug may interfere with the mower’s stock chute deflector—you might need to remove or reposition it for proper clearance.
• Performance: Works best with sharp mulching blades (sold separately); without them, you’ll get uneven clippings and clumping in tall grass.

Should You Buy It

Buy this if you own a Cub Cadet Xtreme S with a 42-inch fabricated deck and want to mulch without buying a separate mulching deck. Skip it if you have a stamped deck, a different brand, or prefer side discharge—this plug is a one-trick solution for mulching only.