731-09312 Mulch Plug 30" Deck for MTD, Craftsman, Troy-Bilt Lawn Mower, Also for CR30 TB30R R-105 R-110 R-140 R-1500, Replace 19A30013

What It Is

This is a mulch plug (part 731-09312) that blocks the side-discharge chute on 30-inch cutting decks, forcing grass clippings to recirculate for finer mulching. It’s designed for specific MTD-built tractors and zero-turn mowers.

Fitment & Compatibility

Before buying, measure your deck width—this plug fits only 30-inch decks. It replaces OEM part 19A30013 and fits MTD, Craftsman, Troy-Bilt, and Cub Cadet models with a 30” fabricated or stamped deck. Compatible with Troy-Bilt CR30, TB30R, R-105, R-110, R-140, R-1500, and similar series. Check your mower’s model number (not engine model) against the manufacturer’s parts lookup to confirm. This is an OEM Troy-Bilt part, not a universal aftermarket—stick with it for guaranteed fit on listed machines.

Key Things to Know

• Installation is simple – No tools needed; it snaps into the discharge opening and secures with a spring clip or latch (check your deck design).
• Quality matches OEM – Made of durable plastic with a rubber seal to prevent clumping and leaks. Users report a tight fit with no rattling.
• Common gotcha – If your deck has a separate side-discharge deflector that must be removed first, do that before installing the plug. Some models require flipping the deflector up or unbolting it.
• Works best with a mulching blade – For optimal fine clippings, pair with a dedicated mulching blade (not the standard high-lift blade). This plug alone won’t improve mulching if blades are worn.

Should You Buy It

If you own a 30-inch MTD/Craftsman/Troy-Bilt tractor or zero-turn and want to convert from side-discharge to mulching without buying a full kit, this plug is a straightforward, affordable solution. It’s ideal for homeowners who mow frequently and want to return nutrients to the lawn. Skip it if you prefer bagging or have a deck size other than 30 inches.