Toro Genuine OEM (Fits Exmark) 138-7597 Flat Idler Pulley Timecutter/Titan and Exmark Quest Z-Turn Riding Mowers

What It Is

The Toro 138-7597 is a flat idler pulley used to tension and guide the mower deck belt on select Toro TimeCutter and Titan zero-turn mowers, as well as Exmark Quest Z-turn models. It’s a genuine OEM replacement part, not an aftermarket copy.

Fitment & Compatibility

• Check your model number: Fits Toro TimeCutter models (e.g., 74712, 74715, 74716, 74717, 74718, 74719, 74720, 74721, 74722, 74723, 74724, 74725, 74726, 74727, 74728) and Titan models (e.g., 74750, 74751, 74752, 74753, 74754, 74755, 74756, 74757, 74758, 74759). Also fits Exmark Quest models (e.g., QZS602, QZS603, QZS722, QZS723).
• Deck size: Typically used on 42", 44", 50", 54", and 60" decks. Confirm your deck size and belt routing diagram.
• Measurements: The pulley has a 3.5" outer diameter, 5/8" inner bore, and 0.5" belt width. Measure your old pulley before ordering to verify.
• OEM vs aftermarket: This is a genuine Toro part (also branded for Exmark). Aftermarket pulleys may have different bearing quality or dimensions—stick with OEM for exact fit.

Key Things to Know

• Quality: OEM pulleys have sealed ball bearings that last longer than cheap replacements. Expect several seasons of normal use.
• Installation difficulty: Easy. Remove belt, unbolt old pulley (usually a 5/16" or 3/8" hex bolt), install new one, and re-tension belt. No special tools required.
• Common gotcha: The pulley bolt can be stubborn if rusted. Use penetrating oil and a breaker bar. Don’t overtighten—torque to 15-20 ft-lbs.
• Inspect the belt: While replacing the pulley, check the deck belt for cracks or wear. A bad pulley can damage a good belt.

Should You Buy It

Buy this if your Toro TimeCutter, Titan, or Exmark Quest has a noisy, wobbling, or seized idler pulley. It’s a direct-fit OEM part at a fair price—worth the small premium over generic pulleys for reliable performance and exact fitment.