Hydro-Gear ZT-2800 — ZH-GMBB-SB5B-1PXX (representative image) Click to zoom

Hydro-Gear ZH-GMBB-SB5B-1PXX ZT-2800 Hydrostatic Transaxle

MPN ZH-GMBB-SB5B-1PXX

Free shippingIn stockHydrostatic Transaxle

Overview

Hydro-Gear ZH-GMBB-SB5B-1PXX is a genuine Hydro-Gear ZT-2800 hydrostatic transaxle. The ZT-2800 is Hydro-Gear's estate-grade transaxle — "our most rugged residential transaxle for machines up to 1000 lbs."

Order by the full model number on the Hydro-Gear label (ZH-GMBB-SB5B-1PXX). 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 ZT-2800 guide · Shop all ZT-2800 transaxles

Specifications

Brand Hydro-Gear (genuine)
Model / part number ZH-GMBB-SB5B-1PXX
Series ZT-2800
Type Hydrostatic Transaxle
Pump / motor displacement 10 cc/rev pump, 16 cc/rev motor (series spec)
Input speed 3000 rpm max (non-charged) / 3600 rpm (charged), 1800 rpm min (series spec)
Output torque (up to) 300 lb-ft (406 Nm) (series spec)
Speed (up to) 8 mph (series spec)
Max machine weight 1000 lb (453 kg) gross vehicle weight (series spec)
Axle 1.0 in (25.4 mm); tapered, 4-bolt or 5-bolt flange (series spec)
Unit weight 32 lb (14.5 kg) (series spec)
Reduction 20.69:1 (ZH prefix, series spec)
Fluid 20W50 engine oil (series spec)
Filter External spin-on, Hydro-Gear 52114 (25 micron nominal / 40 absolute)

Service notes

  • Oil and filter: 20W50 engine oil and Hydro-Gear filter 52114. First change at 75–100 hours, then every 400 hours.
  • Capacity is about 2 qt per transaxle (56.6–71.9 fl oz depending on configuration), excluding the expansion tank and hose.
  • 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 ZH-GMBB-SB5B-1PXX 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 ZH-JPBB-SF7B-2XLX. 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.