Husqvarna 574870901 3400 Hydro Belt – Genuine OEM Replacement Drive Belt

Part Number: 574870901
Category: Zero-Turn Mower Replacement Parts & Hydrostatic Drive Components
Type: 3400 Hydro Belt – Genuine OEM Replacement Drive Belt

The Husqvarna 574870901 3400 Hydro Belt is a genuine OEM replacement drive belt designed for select Husqvarna zero-turn mowers, riding mowers, and compatible hydrostatic drive systems.

Product Specifications

• Part Number: 574870901
• Manufacturer: Husqvarna
• Product Type: Hydrostatic Drive Belt
• Factory Designation: Belt, Hydro, 3400
• Alternate Description: Hydro Belt / Hydro Drive Belt / Ground Drive Belt / Transmission Drive Belt / Zero-Turn Drive Belt
• Component Type: Drivetrain / Hydrostatic Transmission Component
• Primary Application: Lawn & Garden Equipment
• Common Equipment Types: Zero-Turn Mowers / Riding Mowers – Model Dependent
• Known Equipment Families: Husqvarna MZ / M-ZT Series and Related Equipment – Model Dependent
• System: Hydrostatic Ground Drive / Transmission System
• Function: Transfers Engine Power to the Applicable Hydrostatic Transmission Drive System
• Installation Location: Engine / Hydro Transmission Drive System – Model Dependent
• Associated Components: Engine Pulley / Hydro Transmission Pulleys / Idler Pulleys / Idler Arm / Tensioning Components / Belt Guides
• Factory Application Designation: 3400
• Replacement Type: Direct OEM Replacement
• OEM Status: Genuine Husqvarna OEM Part
• Condition: New
• Quantity: 1 Hydro Drive Belt
• Part Number Reference: 574870901
• Alternate Number Format: 574 87 09-01 / 5748709-01

Features & Benefits

• Genuine Husqvarna OEM replacement hydro drive belt
• Factory-designated Belt, Hydro, 3400
• Designed for compatible Husqvarna hydrostatic drive systems
• Used on select Husqvarna MZ and M-ZT zero-turn mower configurations
• Replaces the applicable original equipment hydro transmission belt
• Transfers engine power to the mower's hydrostatic drivetrain
• Helps maintain consistent power delivery to the transmission system
• Supports proper mower propulsion and ground-drive operation
• Application-specific belt profile, length, construction, and fit
• Designed to follow the intended factory pulley routing
• Interfaces with applicable OEM engine, hydro, and idler pulleys
• Helps restore drive performance when replacing a worn or slipping belt
• Suitable for replacing cracked, glazed, frayed, stretched, burned, damaged, or broken belts
• Useful for hydrostatic drivetrain repair and preventative maintenance
• Direct replacement for equipment specifying 574870901
• Sold individually

Hydro Drive Belt Function & Importance

The 574870901 Hydro Belt forms part of the power-transmission system responsible for propelling compatible Husqvarna zero-turn and riding mowers.

A simplified hydrostatic drive arrangement can be represented as:

Engine Drive Pulley → 574870901 Hydro Belt → Idler / Tensioning System → Hydro Transmission Pulley(s) → Hydrostatic Drive System → Drive Wheels

As the engine operates, the belt transfers rotational power from the engine pulley to the applicable hydrostatic transmission system. The transmissions then convert and regulate this power to produce mower movement according to operator control input.

Proper hydro belt operation helps provide:

• Efficient drivetrain power transfer
• Consistent mower propulsion
• Proper operation of the hydrostatic transmissions
• Smooth forward and reverse response
• Reliable interaction with the transmission drive pulleys
• Correct operation of associated idlers and tensioning components
• Maintenance of the intended factory drivetrain configuration

A worn or damaged hydro belt may contribute to slipping, squealing, hesitation, reduced ground speed, weak propulsion, inconsistent drive response, difficulty moving under load, repeated belt derailment, or complete loss of ground drive.

Because similar symptoms can also result from hydrostatic transmission problems, damaged pulleys, worn idlers, incorrect belt tension, or other drivetrain issues, the complete drive system should be inspected when diagnosing propulsion problems.

Replacement, Inspection & Installation

Replacement of the Husqvarna 574870901 3400 Hydro Belt may be appropriate if the original has:

• Developed visible cracks
• Become brittle or hardened
• Developed shiny or glazed sidewalls
• Shows burned or overheated areas
• Developed frayed or damaged edges
• Become stretched or excessively loose
• Slips during equipment operation
• Repeatedly comes off the pulley system
• Sustained cuts or other physical damage
• Broken completely

When replacing the belt, inspect the surrounding engine pulley, hydro transmission pulleys, idler pulleys, idler arm, tensioning mechanism, springs, belt guides, pulley bearings, and mounting hardware for wear or damage.

Before beginning service, park the mower on a stable, level surface, disengage the cutting system, set the parking brake, shut off the engine, remove the ignition key, allow all moving components to stop, and prevent accidental starting or unintended movement.

Before removing the original belt, note or photograph the exact belt routing, pulley arrangement, idler position, belt-guide locations, and tensioning configuration.

Install the replacement 574870901 Hydro Belt according to the applicable OEM belt-routing diagram. Verify that the belt is properly seated in each pulley groove and correctly routed around all applicable idlers and guides.

After installation, verify proper belt alignment and tension and confirm that the drivetrain responds correctly to forward and reverse control inputs before returning the mower to normal operation.

Fitment & Important Notes

• Verify compatibility with your exact Husqvarna mower model, product number, serial number, hydrostatic transmission configuration, and production revision before ordering.
• Match part number 574870901 directly with the applicable OEM parts documentation.
• 574870901 is identified as Belt, Hydro, 3400 for applicable Husqvarna equipment.
• Known applications include select Husqvarna MZ48, MZ52, MZ54, MZ61, MZ6128, M-ZT52, M-ZT61, and related zero-turn mower configurations.
• Fitment varies by specific product number and production revision even within the same mower family.
• The “3400” designation is a factory/application reference and should not be treated as a belt dimension.
• Do not assume every Husqvarna MZ, M-ZT, riding mower, or zero-turn mower uses 574870901.
• This is a hydro/ground-drive belt on applicable equipment and should not be confused with the mower deck blade-drive belt.
• The exact belt length, width, profile, construction, and routing are equipment dependent.
• Similar-looking belts can differ in length, width, sidewall profile, construction, load characteristics, and drivetrain compatibility.
• Do not select a replacement belt solely by approximate dimensions or visual appearance.
• Use 574870901 as the primary OEM fitment reference.
• Inspect all idler and transmission pulleys for rough bearings, excessive play, damaged grooves, misalignment, or debris buildup when replacing the belt.
• Inspect the idler arm and tensioning components if the previous belt repeatedly slipped or came off.
• A seized pulley, worn bearing, damaged tensioning component, or incorrect routing can cause premature failure of a new hydro belt.
• Keep oil, grease, hydraulic fluid, fuel, and other contaminants away from the belt and pulley surfaces.
• Do not cut, stretch, splice, grind, reshape, or otherwise modify the replacement belt to force fitment.
• This listing is for one Husqvarna 574870901 3400 Hydro Belt only unless otherwise specified. Pulleys, idlers, tensioning components, hydro transmissions, and other associated drivetrain parts are sold separately unless explicitly included.
• Match Husqvarna 574870901 with your mower's OEM parts documentation before ordering to ensure proper fitment.