1978–1984 Kubota B5100, B6100 & B7100 I&T Shop Service Manual – Gear & HST (P/N K-2)

This condensed Intertec I&T shop-manual section covers Kubota B5100D/E, B6100D/E, B6100HST-D/E, B7100D, and B7100HST-D/E tractors in two-wheel-drive, four-wheel-drive, gear-transmission, and hydrostatic configurations. The material was previously contained in Shop Service Manual No. K-2, copyright 1986. It is the tractor section, not the complete volume or a Kubota factory manual.

The download contains 46 pages across three scanned PDF files, without searchable text or embedded PDF bookmarks.

• Engine repair: Removal and installation, cylinder-head and valve-train service, timing-gear alignment, piston and rod work, camshaft and crankshaft overhaul, dry cylinder-liner replacement, oil-pump inspection, and governor service.

• Hydrostatic transmission: Case-, charge-, and high-relief-pressure tests, vacuum testing, neutral and speed-control linkage adjustment, unit removal, internal inspection, reassembly, and operational checks.

• Six-speed transmission and clutch: Tractor splitting, clutch centering and release-lever checks, shifter mechanisms, gear and shaft inspection, and model-specific transmission layouts.

• Axles, steering and PTO: Steering-gear and axle service, differential-lock and final-drive overhaul, brake repair, rear PTO, HST mid-PTO, and PTO one-way clutches.

• Hydraulic lift: Fluid and filter service, relief-pressure testing, implement-lowering adjustment, pump and control-valve repair, lift-cover overhaul, and the optional external-attachment hydraulic block.

• Cooling and electrical: Thermo-siphon cooling and fan-belt data, glow-plug testing, alternator output specifications, Nippon Denso starter inspection, and two model-specific wiring schematics.

The dense repair procedures and measurement requirements make it best suited to mechanics and experienced owners who already have the pullers, dial indicators, pressure gauges, holding fixtures, and lifting equipment required for tractor teardown.

Engine, Fuel and Electrical Service

The condensed service-data tables identify the engine installed in each tractor group: the two-cylinder Z500-1A in the B5100D/E, D650-A in the B6100D/E, D650-AH in the B6100HST-D/E, D750-A in the B7100D, and D750-AH in the B7100HST-D/E.

Those tables organize tune-up data, engine dimensions, wear limits, capacities, approved fluids, and U.S./metric specifications by configuration.

Fuel-system material covers bleeding and injection timing plus injector opening-pressure, seat-leakage, and spray-pattern testing. Injection-pump testing and overhaul are assigned to a qualified diesel shop; recalibration requires specialized equipment and training.

Starter coverage adds no-load testing and pinion-engagement adjustment. The cooling section describes the alternator-mounted fan and belt adjustment.

HST Types and Transmission Repair

The hydrostatic sections distinguish Type I and Type II units by tractor serial number:

Earlier serial numbers use Type I. The corresponding cross-sections and assembly details help identify the correct HST layout before repair information or replacement components are selected.

HST assembly: Pistons and cylinder blocks are matched sets, and the pump-side valve plate has two identification notches. The port-block installation notes explain shaft protection to prevent seal-lip damage. Relief-valve seat removal specifies Kubota tool 07916-60841 or an equivalent.

Gear and range units: Separate illustrations show six-speed layouts for B5100D/E, B6100D/E, and B7100D, plus the two-speed range transmissions fitted to HST models. Engine/clutch-housing and clutch-housing/transmission-case splits are documented, with clutch-centering and release-lever measuring tools.

Service data includes component-specific torque specifications, gear backlash and end play, bearing and bushing clearances, hydraulic test pressures, and electrical test values.

Axles, PTO and Hydraulic Lift

Steering and axle sections cover kingpins, pivot bushings, toe-in, front-drive housings, axle shafts, differentials, and bevel gears. The B7100HST-D has its own front-drive layout; B5100D/E final drives and brakes are also distinguished from the other models.

Lift relief-pressure testing specifies tool kit 07916-50041. Lift-cylinder illustrations distinguish early pistons with an O-ring from later pistons fitted with both an O-ring and seal ring, and show the diverter-valve cylinder head used on some models.

An incorrectly set control-rod interlock can allow excessive universal-joint angle when operating a three-point-mounted tiller or mower and damage the PTO drive shaft.

Figures, Wiring and Scope

Numbered illustrations run through Fig. 106. They combine exploded assemblies, section views, test setups, and adjustment drawings. Examples include the drive-gear timing diagram, Type I and Type II HST cross-sections, the HST pressure-test port view, model-specific range-transmission gear and shaft layouts, and the hydraulic pump-to-control-valve line view.

The final two pages provide separate wiring schematics for the B5100D/E and B6100D/E group and for the B6100HST-D/E, B7100D, and B7100HST-D/E group. Figure 105 supplies the shared wire-color legend.

Exploded-view callouts support disassembly and correct installed position, but this publication is not a parts-ordering catalog. Tractor splitting, raised-machine support, injector testing, rotating PTO work, and hydraulic pressure checks require the securing, lifting, isolation, and test practices specified for the job.

File Format and Readability

• Part 1: 18 pages, including the cover and four introductory/service-data pages.
• Part 2: 12 pages, continuing with printed pages 19-30.
• Part 3: 16 pages, printed pages 31-46, including both wiring schematics.

The cover, introductory material, and wiring pages are already included in the 46-page total. There are no separate supplements.

The printed index points to numbered service paragraphs. Small switch-terminal markings and wire-color labels on the wiring diagrams are readable when enlarged, although the scans remain slightly soft.