Hydro-Gear ZT-2100 — ZF-ATBB-3D5A-3PTX (representative image) Click to zoom

Hydro-Gear ZF-ATBB-3D5A-3PTX ZT-2100 Hydrostatic Transaxle

MPN ZF-ATBB-3D5A-3PTX

Free shippingIn stockHydrostatic Transaxle

Overview

Hydro-Gear ZF-ATBB-3D5A-3PTX is a genuine Hydro-Gear ZT-2100 hydrostatic transaxle. Hydro-Gear model prefix ZF identifies the ZT-2100, covered in the same service manual as the EZT (ZT-2200).

Order by the full model number on the Hydro-Gear label (ZF-ATBB-3D5A-3PTX). Hydro-Gear builds each model to an OEM specification and advises against substituting a different model, so match every character; zero-turns use a left and a right unit — check which side you need.

More on this series: Hydro-Gear EZT (ZT-2200) guide · Shop all EZT transaxles

Fits these mowers

Brand Model
Toro Timecutter 34, 42, 50" (75750), (75753)

Used as a pair with ZF-DTBB-3D5A-2PTX on Toro Timecutter 34, 42, 50" (75750), (75753) — check your label for which side you have.

Fitment from Hydro-Gear's cross-reference. Always confirm the number on your unit's label before ordering.

Specifications

Brand Hydro-Gear (genuine)
Model / part number ZF-ATBB-3D5A-3PTX
Series ZT-2100
Type Hydrostatic Transaxle
Fluid 20W50 engine oil; 54 fl oz (1597 ml) (series spec)

Service notes

  • Hydro-Gear's ZT-2100/ZT-2200 manual says these units are factory filled and sealed and do not require routine oil maintenance.
  • After installing, purge air from the system following Hydro-Gear's procedure: wheels off the ground, cycle forward/reverse 5–6 times with the bypass open, then 5–6 times closed, and top up the oil.

Shipping and price

  • Free shipping (lower 48).
  • Low Price Guarantee: find a lower advertised price on a genuine Hydro-Gear ZF-ATBB-3D5A-3PTX and we'll beat it by 5% (before purchase). Details.

Frequently asked questions

Where do I find my Hydro-Gear model number?

On the Hydro-Gear label on the unit (on the transaxle). Current numbers look like ZC-DUBB-4MDC-3PPA. See how to find your Hydro-Gear part number.

Can I use a different model that looks the same?

Hydro-Gear strongly discourages using any model not originally specified by the mower maker; similar-looking units can differ internally. Order the exact number on your label.