PTO Clutch Fitment Guide

Finding the right electric PTO clutch comes down to one thing above everything else: the OEM part number printed on the clutch you’re replacing. This guide shows you exactly where to find it, what it looks like, and how to use it to identify a correct match.

PTO Clutch Fitment Guide with illustrations of clutch components and text on a blue background.

1. Locate the OEM Part Number (Fastest & Most Accurate)

Every electric PTO clutch has a reference number engraved, stamped, or sticker-labeled directly on the clutch housing. Common locations include:

  • The outer metal shell
  • The coil or magnet housing
  • The backing plate
  • The hub area near the crankshaft bore
  • A sticker label on the side of the clutch

Examples of what these numbers look like:

917-05121, 09266700, 5218-102, AM141536, 717-04376A

Enter that number exactly as shown in the search bar to jump straight to the correct replacement. This is the most accurate and fastest way to match a PTO clutch.

2. Matching by Brand or Model (Backup Method)

If your OEM part number is missing or unreadable, the next best method is to identify your mower by brand, mower series, and model. PTO clutches are often shared across multiple mower platforms, so narrowing down your equipment is the fastest way to confirm fitment.

Start by selecting your mower brand below. Each brand guide includes model-specific PTO clutch fitment pages to help you identify the correct replacement quickly.

Once inside your brand guide, follow the model-specific links to match your exact mower and confirm the correct PTO clutch replacement.

If you prefer to browse available options directly, you can also explore our brand collections, including Cub Cadet, John Deere, Husqvarna, Ariens, Gravely, Toro, Exmark, Scag, and more.

This method works well when the OEM number is unavailable, but keep in mind that part numbers can vary by production year and configuration. Whenever possible, matching by OEM part number is still the most accurate method.

3. Key PTO Clutch Specs You Should Know

These core specifications must match your original clutch for proper operation:

  • Rotation: CW (clockwise) or CCW (counter-clockwise) — using the wrong rotation can prevent proper engagement and belt tracking.
  • Pulley Diameter: Common sizes include 5.90", 6.00", 6.10", 7.10", etc. The pulley must be close to OEM spec to maintain correct belt length and speed.
  • Crankshaft Bore: Usually 1" or 1-1/8". The bore size must match your engine crankshaft exactly.
  • Mounting Height: The overall height of the clutch must match the OEM unit so your belt lines up correctly and tension stays within spec.

If any of these dimensions are significantly off, the clutch may not engage properly, may slip, or can cause premature belt wear.

4. If Your Number Doesn’t Show Up

If search returns no results for your part number, try these steps:

  • Check for suffixes like A, B, X, or P — sometimes the base number is what matters (for example, 05121 vs. 917-05121).
  • Search a shortened version (e.g., try “05121” instead of “917-05121”).
  • Try related brands — many OEM clutches cross over between MTD-built units such as Cub Cadet, Troy-Bilt, Craftsman, White Outdoor, and others.

If you’re still not sure, you can always reach out with your part number and we’ll help confirm compatibility.

5. Find the Correct Clutch in Seconds

Best method: Use the search bar with the exact OEM part number printed on your original clutch. That will almost always take you straight to the correct replacement.

Best for browsing: If you don’t have the clutch in front of you, you can explore our brand collections, including Cub Cadet, John Deere, Husqvarna, Ariens, Gravely, Toro, Exmark, Scag, and more.

Frequently Asked Questions

These are the most common questions customers ask when identifying the correct electric PTO clutch replacement.

How do I know which PTO clutch fits my mower?

The most accurate method is to use the OEM part number stamped on your original clutch. Enter that number into the search bar exactly as shown. Matching by brand or mower model works as a backup, but OEM numbers give the most reliable results.

Where do I find the OEM number on my old clutch?

Most PTO clutches have the number engraved, stamped, or sticker-labeled on the outer shell, the coil housing, the backing plate, or near the crankshaft bore. If it's faded or missing, try searching shortened versions of the number or contact us for help.

What if my part number doesn’t come up in search?

Try removing suffixes such as A, B, X, or P, searching the base number (e.g., 05121), or checking related brands — many OEM clutches overlap between MTD-built units like Cub Cadet, Troy-Bilt, and Craftsman. If you’re unsure, message us and we’ll confirm compatibility.

Can I match a clutch by the mower model alone?

You can — but it’s less reliable. Model numbers often span multiple clutch versions. If your OEM number is available, always use that instead. If not, match by brand collection and verify rotation, pulley size, and bore diameter.

What if I receive the wrong PTO clutch for my mower?

At PTO Direct USA, we stand behind our Fitment Guarantee. If the clutch you receive does NOT match the specifications of your OEM clutch due to an incorrect part number listed on our product page, a manufacturing defect, or a shipping error, we will replace it or refund it — as long as the clutch has not been installed or test-mounted.

If something about the clutch appears incorrect, do not install the unit. Installation leaves permanent marks that prevent the part from being returned or resold.

Instead:

• Take a photo of the clutch and OEM tag if available

• Contact us with your order number

• Our team will verify the OEM cross-reference and resolve the issue quickly

What if I need help finding the right part?

We’re here to help. Use the contact form and include your OEM number (or the mower model/deck size if the number is missing). We'll guide you to the correct replacement and let you know if we can bundle additional mower parts with your order.