Stens 285-821 285-821 Caster Spacer

What It Is

The Stens 285-821 Caster Spacer is a replacement spacer used to maintain proper clearance between the caster wheel and the mounting bracket on zero-turn mowers and some lawn tractors. It prevents wheel binding and ensures smooth pivoting during turns.

Fitment & Compatibility

Before buying, verify the following:

• Measure the inner diameter (ID): This spacer has a 0.515” ID. If your caster bolt or axle is larger or smaller, it won’t fit.
• Check the outer diameter (OD) and length: The OD is 0.875” and the length is 1.125”. Measure your old spacer to confirm these match.
• Brand/model fit: Stens 285-821 is a direct replacement for OEM spacers on many Gravely, Ariens, Husqvarna, and Bad Boy zero-turn mowers. It also fits some older MTD and Cub Cadet models. Cross-reference with your mower’s parts diagram.
• OEM vs aftermarket: This is a non-OEM aftermarket part, but Stens is a reputable manufacturer. If your mower is still under warranty, an OEM spacer may be required to avoid voiding coverage.

Key Things to Know

• Quality: Made from steel with a zinc-plated finish for corrosion resistance. Holds up well under normal mower use, but not designed for heavy-duty or commercial abuse.
• Installation: Simple—just remove the caster wheel, slide the old spacer off, install the new one, and reassemble. No special tools needed beyond a wrench and possibly a hammer to tap it into place.
• Common gotchas: The spacer can seize to the caster bolt over time due to rust. Apply anti-seize compound during installation to make future removal easier. Also, check that the spacer isn’t too long for your bracket—if it protrudes, it can cause wheel wobble.
• Quantity: Sold individually. Most mowers need two spacers per caster wheel (one on each side of the wheel). Order accordingly.

Should You Buy It

If you need to replace a worn, rusted, or missing caster spacer on a zero-turn mower and you’ve confirmed the measurements match, this Stens spacer is a solid, affordable choice. It’s best for DIY homeowners and light-commercial users who want a reliable fix without paying OEM prices. Avoid if you need a heavy-duty commercial part or if your mower uses a non-standard bolt size.