0.6" x 149.625" Deck Belt for 48" Decks Fits Kubota Zero Turn Mowers ZG123S ZG124E Z121SKH Z122EBR

What This Is

This is a new aftermarket mower deck drive belt that replaces Kubota OEM part number K5579-36710. It is the belt that drives the blade spindles under the cutting deck, so a worn, cracked, glazed, or stretched belt shows up as slipping blades, poor cut quality, belt squeal, or blades that will not spin. Installing a fresh belt restores full, reliable power from the engine to the deck.

Fitment

This belt fits Kubota zero-turn mowers equipped with the 48 inch RCK48P cutting deck, which covers popular models such as ZG123S, ZG124E, Z121SKH, and Z122EBR. Kubota uses the same deck across several model years and trims, so the most reliable way to confirm fit is by your deck size and deck part number rather than by model name alone. If your machine uses a different deck width, order the belt matched to that specific deck.

Specifications

The belt measures approximately 5/8 inch (0.6 inch) wide by 149.625 inch outside length, and is about 0.45 inch thick. It is a wrapped, molded B-section belt built with aramid (Kevlar type) cord for high tensile strength, heat resistance, and long service life under the shock loads a cutting deck sees. Independent catalogs quote the outside length anywhere from 149.3 to 150 inches for this same belt, which is normal measuring variation for one part.

What Is Included

You receive one (1) deck belt. No pulleys, idlers, tensioner springs, or hardware are included. Inspect your idler pulleys and tensioner while the old belt is off, since a seized idler is a common cause of premature belt failure.

Cross-Reference

This belt cross-references common aftermarket replacements including Stens OEM-replacement belts for Kubota RCK48P decks, Rotary 15330, and D&D PowerDrive 5423. These are reference numbers to help you confirm the correct part. The genuine Kubota number is K5579-36710.

Ordering Guidance

Match the belt to your Kubota 48 inch RCK48P deck before ordering. If you are unsure, check the belt routing diagram on your deck or the deck part label, and measure your old belt. Ordering by deck rather than by model name avoids the most common fitment mistakes on zero-turn mowers.