Lawn Mower Parts 783-06424A-0637 783-06424A Black Deck Belt Cover, Compatible with MTD Craftsman Troy Bilt 783-06424A-0637 42" 46" Deck Spindle Pulley Belt Guard Cover (2)

What It Is

This is a black plastic belt guard cover (OEM replacement 783-06424A) that sits over the spindle pulley on 42" and 46" MTD-built lawn tractor decks. It protects the drive belt from debris and prevents accidental contact with the spinning pulley.

Fitment & Compatibility

Check three things before buying:

• Deck size: Fits 42" and 46" stamped-steel decks on MTD, Craftsman, Troy-Bilt, and Yard Machines tractors. Does not fit 50" or 54" decks.
• OEM number: Cross-references to 783-06424A, 783-06424A-0637, and 783-06424. If your original has a different number, measure the mounting hole spacing (approx. 3.5" center-to-center) and overall width (~6.5").
• Mounting: Uses two 5/16" bolts (not included). Verify your deck has threaded holes or existing studs in the correct locations—some models use push-on clips instead.

The pack includes two covers, so you can replace both spindles if your deck has dual pulleys.

Key Things to Know

• Material: Dense, UV-resistant black plastic—holds up well but can crack if overtightened. Hand-tighten bolts until snug, then add 1/4 turn.
• Installation: 5-minute job with a 10mm socket or wrench. No need to remove the deck or belt. Access from underneath or through the discharge chute.
• Common gotcha: Some 46" decks have a slightly different bolt pattern on one spindle. Test-fit before tightening both sides.
• Aftermarket note: This is a non-OEM replacement but matches the original dimensions and hole alignment. A few users report needing to file the hole edges for a perfect fit on older decks.

Should You Buy It

If your original belt guard is cracked, missing, or the belt keeps jumping off, this is a direct, low-cost fix. It’s ideal for DIY owners with 42" or 46" MTD-style decks who want a quick, no-mod installation. Skip it if you have a 50"+ deck or a completely different bolt pattern—measure first.