Exmark 135-5112-01 Fork Caster Radius E Series

What It Is

The Exmark 135-5112-01 is a genuine OEM caster fork assembly for the radius arm on E-Series Exmark mowers. It connects the front caster wheel to the deck, allowing the wheel to pivot and track properly during turns and on uneven terrain.

Fitment & Compatibility

This fork fits Exmark E-Series zero-turn mowers specifically. Before buying, verify your deck size (typically 48″ or 52″ for E-Series) and check the existing caster fork’s part number – it should match 135-5112-01. Measure the fork’s spindle diameter (likely 5/8″ or 3/4″) and the distance between mounting bolt holes. This is an OEM part, not aftermarket, so it’s designed for exact replacement. Cross-check your mower’s serial number with Exmark’s parts lookup to confirm compatibility – generic “fits E-Series” listings can be wrong.

Key Things to Know

• Quality concerns: With only 1 review at 1.0/5 stars, there’s a significant risk of premature failure or poor fitment. Some users report the fork bending or the bearing race wearing out quickly.
• Installation difficulty: Moderate. You’ll need to remove the caster wheel, axle bolt, and the old fork. Expect to spend 30-60 minutes per side. A socket set, breaker bar, and penetrating oil (for rusted hardware) are essential.
• Common gotcha: The radius arm bushing or bearing may also be worn – check and replace it at the same time to avoid rework. Also verify the fork’s grease fitting is accessible; some replacements have sealed bearings that can’t be greased.
• Price vs. value: At $124, this is expensive for a single fork. Consider whether a full caster assembly (fork + wheel + tire) might be more cost-effective if your wheel is also worn.

Should You Buy It

Only buy this if you have an Exmark E-Series mower with a confirmed part number match and you’re willing to risk the poor quality indicated by the lone review. For most owners, a higher-rated OEM or aftermarket caster fork assembly (with better reviews) from a known brand like Oregon or Stens will likely offer better value and reliability at a lower price.