How to Identify the Correct PTO Clutch by OEM, Warner, or Ogura Number

Finding the right electric PTO clutch starts with the numbers and specs on your original clutch. The best match usually comes from the OEM part number stamped, engraved, or labeled on the clutch body. If that label is missing, worn off, painted over, or unreadable, a Warner or Ogura manufacturer number can often identify the same clutch family.

Already have the correct replacement? Before installing it, review our PTO Clutch Installation Guide for removal tips, wiring checks, torque guidance, and burnishing steps.

Many OEM mower clutches are built around proven Warner PTO clutch systems and Ogura PTO clutch systems, which is why manufacturer markings can be just as useful as mower-brand labels during identification.

Close-up of a PTO clutch installed under a mower, with labeled arrows identifying the Warner number 5219-52 and OEM number 717-04180 stamped on the clutch housing.
The OEM part number is the best way to confirm PTO clutch fitment. Check the clutch housing, backing plate, sticker label, or coil area before matching your replacement.

1. Start With the Number on the Original Clutch

The fastest way to identify a PTO clutch replacement is to match the number on the clutch you are removing. That number may be an OEM mower-brand number, a Warner number, or an Ogura number.

Common places to check include:

  • Outer metal clutch shell
  • Coil or magnet housing
  • Backing plate
  • Hub area near the crankshaft bore
  • Side sticker or label
  • Stamped markings near the bearing, pulley, or wire lead area

Common OEM number examples: 917-05121, 09266700, AM141536, 717-04376A, 759-05064

Common Warner number examples: 5219-91, 521991, 5218-102

Common Ogura number examples: MA-GT-JD2, MAGTJD2, MA-GT-JD11, MAGTJD11

Format tip: Warner and Ogura numbers may appear with or without dashes. For example, 5219-91 and 521991 may point to the same Warner number style. Ogura numbers can work the same way, such as MA-GT-JD2 and MAGTJD2. Search the exact number first, then try the same number with dashes removed or added.

2. Use Brand and Model as a Backup Method

If the original clutch number is missing or unreadable, identify the mower by brand, full model number, serial number, deck size, and engine configuration. This can narrow the search, but it is not as reliable as matching the number on the clutch itself.

Start with the closest brand guide or collection:

Fitment note: Model-based searching is helpful, but mower models can vary by year, engine package, deck size, and serial range. Confirm the clutch specs before ordering.

3. Confirm the Critical PTO Clutch Specs

A PTO clutch that bolts onto the crankshaft is not automatically correct. The belt drive, wiring, rotation, and mounting setup still need to match the original unit.

  • Crankshaft Bore: Usually 1 inch or 1-1/8 inch. This must match the engine crankshaft exactly.
  • Pulley Diameter: The pulley must stay close to OEM spec for correct belt speed and belt tension.
  • Rotation: PTO clutches may be CW or CCW depending on the mower application.
  • Overall Height: Height affects belt alignment, frame clearance, and deck belt tracking.
  • Wiring Style: Some replacements use universal leads or a different connector style.
  • Anti-Rotation Bracket: The stop bracket or tab must align with the mower frame or engine plate.

If any of these details are wrong, the mower may experience belt slip, poor blade engagement, premature belt wear, electrical problems, or clutch damage.

4. What to Do if Search Does Not Find Your Number

If your clutch number does not show a result right away, try a few variations before assuming the part is unavailable.

  • Search the full number exactly as shown.
  • Search the base number without suffixes such as A, B, X, or P.
  • Try a shortened version, such as 05121 instead of 917-05121.
  • Try Warner numbers with and without dashes, such as 5219-91 and 521991.
  • Try Ogura numbers with and without hyphens, such as MA-GT-JD2 and MAGTJD2.
  • Check related mower brands, especially MTD-built platforms such as Cub Cadet, Troy-Bilt, Craftsman, White Outdoor, and Yard Machines.

If you are still unsure, email support@ptodirectusa.com with your mower model number, serial number, deck size, visible clutch numbers, and clear photos of the old clutch.

5. Before Installing the New PTO Clutch

Once you identify the correct replacement, inspect the mower before installation. A failed clutch may be caused by normal wear, but wiring issues, poor belt alignment, seized hardware, damaged bearings, or incorrect installation can also cause problems.

Before installing, check:

  • Battery is disconnected before working near the wiring
  • Old clutch slides off without damaging the crankshaft
  • Crankshaft is clean and free of rust, burrs, and debris
  • Keyway and mounting hardware are in good condition
  • Deck belt is routed correctly
  • Wiring is secured away from heat, belts, pulleys, and moving parts
  • Anti-rotation bracket is properly positioned
  • Mounting bolt is torqued to the mower or engine manufacturer’s specification

Old clutch stuck during removal? If the PTO clutch will not slide off the crankshaft, stop before forcing it. Rust, burrs, a tight keyway, or seized hardware can damage the crankshaft if handled aggressively. Follow our PTO clutch stuck on crankshaft guide before prying, hammering, or pulling from one side.

For a full walkthrough, see the PTO Clutch Installation Guide.

6. Find the Correct Clutch Faster

Best method: Search the number stamped, engraved, or labeled on your original clutch.

Backup method: Search by mower brand, model number, serial number, deck size, and engine configuration.

Need help? Email support@ptodirectusa.com with your mower details and clear photos of the old clutch. Include any OEM, Warner, or Ogura numbers visible on the unit.

Frequently Asked Questions

How do I know which PTO clutch fits my mower?

The safest method is to match the number on your original clutch. This may be an OEM mower-brand part number, Warner number, or Ogura number. If no number is readable, use the mower model, serial number, deck size, and clutch specs to narrow the replacement.

Where is the part number located on a PTO clutch?

Check the outer shell, coil housing, backing plate, hub area, side label, and wire lead area. Clean the clutch carefully and inspect all sides before assuming the number is missing.

Can a Warner number replace the OEM number during identification?

Yes. If the OEM label is missing or unreadable, a Warner number can be a strong identification point. Search both dashed and non-dashed formats when needed, such as 5219-91 and 521991.

Can an Ogura number replace the OEM number during identification?

Yes. Ogura numbers can help identify the clutch family when the mower-brand number is gone. Try both hyphenated and non-hyphenated formats, such as MA-GT-JD2 and MAGTJD2.

Why do manufacturer numbers sometimes include dashes and sometimes not?

Dash formatting can vary between stamped markings, printed labels, catalogs, and aftermarket listings. If one version does not show results, search the same number with dashes removed or added.

Can I match a PTO clutch by mower model alone?

Sometimes, but model-only matching is less reliable. The same mower series can use different clutches depending on year, deck size, engine package, and serial range. Confirm bore size, pulley diameter, rotation, wiring style, and mounting layout before ordering.

What if the replacement clutch has a different connector?

Some aftermarket PTO clutches use universal leads or a different connector style. A connector difference does not always mean the clutch is wrong, but the electrical setup must be confirmed before installation.

What if the clutch looks right but the pulley is different?

Do not install it until the specs are verified. A pulley that is too small or too large can affect belt speed, belt tension, blade engagement, and clutch life.

What if I receive the wrong PTO clutch?

PTO Direct USA stands behind its Fitment Guarantee. If something appears incorrect, do not install or test-mount the clutch. Installation can leave marks that prevent return or resale.

Before contacting support, take clear photos of the clutch, pulley, wiring connector, visible labels, and mower model tag. Then email support@ptodirectusa.com with your order number and fitment details.