Kubota GR2120B

Browse aftermarket replacement parts for the Kubota GR2120B garden tractor. Kubota GR Series 21 HP diesel garden tractor B-spec variant with 54-inch deck and 4WD, the bagger-equipped or factory-rear-discharge option in the GR2120 lineup.

Use filters or search by OEM part number to find the right part. Compatibility details are listed on each product page.

Parts Compatible with the Kubota GR2120B Garden Tractor

The GR2120B is the B-spec variant of the GR2120 garden tractor in Kubota's GR Series, distinguished from the base GR2120 by factory bagger or rear discharge mowing deck spec. It uses the same Kubota D902 era 3-cylinder diesel engine, hydrostatic transmission, and 4WD as the base GR2120, with the spec differences confined to the mower deck and discharge plumbing. The GR2120B-2 designation indicates the gen-2 refresh of the same physical machine. Customers commonly find GR2120B units in residential property mowing applications where the bagger or rear-discharge mowing pattern is preferred over the standard side-discharge configuration.

The GR2120B shares the engine and drivetrain service parts with the GR2120 base variant, but the deck and discharge spec differs significantly. The GR2120B is listed separately because the B-spec deck parts are NOT cross-compatible with the base GR2120 mower deck.

Common Replacement Parts for the Kubota GR2120B

Engine service uses Engine Oil Filter HH150-32430 and Fuel Filter 12581-43012 as the primary engine service items for the D902 engine. Cooling system service uses Thermostat 19434-73010.

Internal engine service uses Glow Plug 16851-65510 (original cold start service), Glow Plug 1G679-65512 (later revision), Gear Ring 16871-63820 (the flywheel ring gear), and Guide Oil Gauge 17456-36420. Top-end work uses Exhaust Manifold Gasket 15862-12350. Many of these internal engine parts cross to the GR2120 base variant and other Kubota equipment powered by the same era D902 engine family. Deck-specific parts for the B-spec rear discharge configuration are listed in the product grid below.