964-04007A 664-04007 Grass Bag Compatible with MTD Troy Bilt 21" Lawn Mower Bag, Replacement for 964-04115 664-04011 664-04027 664-04034 Grass Collection Bag (No Frame)

What It Is

This is an aftermarket grass collection bag (model 964-04007A / 664-04007) designed for MTD and Troy-Bilt 21-inch walk-behind mowers. It replaces several OEM part numbers and is intended for side-discharge or mulching mowers that use a rear bagging system without a separate frame.

Fitment & Compatibility

• Deck size: Only for 21-inch mowers. Do not use on 20-inch or 22-inch decks.
• Brands: MTD, Troy-Bilt, Cub Cadet, Yard-Man, Yard Machines, Bolens—any 21-inch model that originally used OEM bag #964-04115, 664-04011, 664-04027, or 664-04034.
• No frame included: This bag attaches directly to the mower’s existing bagging frame or hooks. If your mower requires a separate frame (common on older models), this bag won’t work.
• Check your mower’s model number (on a sticker under the seat or on the frame) and verify the bag attachment points match your existing setup. Measure the bag opening width—it should be roughly 12–14 inches wide.

Key Things to Know

• No frame means lighter, but less rigid – The bag relies on your mower’s frame for support. If your frame is bent or missing, this bag will sag and may not seal properly.
• Installation is easy – Slips onto the existing frame hooks or clips. No tools required.
• Mixed reviews – Some users report the bag fits loosely or the zipper fails after a few seasons. Others say it works fine as a budget replacement.
• Material – Heavy-duty polyester fabric, but not as thick as OEM. Expect 2–3 seasons of regular use.

Should You Buy It

Buy this if you need a quick, low-cost replacement for a worn-out OEM bag on a 21-inch MTD/Troy-Bilt mower and already have a functional bagging frame. Skip it if you want a premium, long-lasting bag or if your mower’s frame is missing or damaged—you’ll need a model that includes the frame.