2011–2013 Isuzu Q Series / QKR 4JB1 Diesel Engine Workshop Service Manual (P/N LNW6ALF000701)

This 11-volume OEM workshop manual set covers the 2011 model-year Isuzu Q Series, with model-specific data for the QKR55 and its 4JB1 and 4JB1-TC diesel engines. Its repair depth and reliance on pullers, gauges, presses, and lifting equipment make it best suited to trained technicians and experienced owners already equipped for workshop-level service.

Models, Systems, and Procedures Included

• Identifies QKR55 configurations used in the brake application tables, including QKR55U-EE1, QKR55L-EE1, QKR55U-HH5, QKR55L-HH5, and QKR55L-FD5, along with chassis, engine-number, and vehicle-identification locations.
• Walks through 4JB1 and 4JB1-TC engine repair, from compression testing and engine removal to cylinder-head work, valve-train inspection, timing-gear installation, crankshaft and piston service, cylinder-block rebuilding, and final adjustments.
• Documents JC52 five-speed transmission and clutch work, including cable adjustment, hydraulic bleeding, transmission replacement, internal shaft and synchronizer repair, clutch master/slave cylinder overhaul, and PTO removal and unit repair.
• Includes axle, brake, and steering procedures for long- and short-wheelbase propeller shafts, full-floating rear axles, drum brakes, manual and power steering, wheel alignment, leaf-spring suspension, and wheel/tire service.
• Details cab and body repair for glass, doors, locks, regulators, seats, instrument panels, cab mounts, complete cab removal, panel sealing, and body sectional views.
• Provides separate left- and right-hand-drive electrical volumes with parts-location drawings, circuit diagrams, connector configurations, fuse/relay/diode maps, grounding points, cable-harness routing, and system-level fault tracing.
• Supplies factory reference data for component-specific torque settings, fluid and lubricant selection, pressure and electrical tests, wear limits, clearances, adjustments, and the special tools specified for the covered repair operations.

Engine and Drivetrain Repair Depth

The engine material goes well beyond routine maintenance. It covers the cylinder head, valve guides and seals, camshaft and tappets, rocker-arm assembly, oil pump, crankshaft, pistons and connecting rods, cylinder liners, and block. The 4JB1/4JB1-TC section adds on-vehicle procedures for the manifolds, oil-cooler-equipped models, front and rear crankshaft seals, flywheel and pilot bearing, timing gears, and complete engine assembly removal and installation.

Fuel-system coverage includes the filter and water separator, engine-specific injection-nozzle disassembly and adjustment, injection-pump removal, and injection-timing adjustment. The manual also contains injection-volume and governor-performance diagrams. Cooling-system repair covers the water pump, thermostat, radiator, and drive-belt adjustment, while the electrical chapter handles the starter, alternator, battery, and QOS II preheating system. Separate sections address EGR-equipped models, catalytic-converter configurations, exhaust-brake applications, and 4JB1-TC turbocharger inspection.

The JC52 transmission volume identifies both JC520T9D and JC521T5H builds. Its unit-repair section breaks down the top-gear, main-shaft, and countershaft assemblies, then extends into PTO repair and clutch hydraulics. Axle procedures distinguish single- and dual-rear-tire full-floating layouts and the 244 mm and 292 mm differentials, including pinion-depth, bearing-preload, backlash, and shim-selection work.

Chassis, Cab, and Electrical Diagnosis

Brake coverage includes two-leading front drum brakes, manual-adjuster rear drums, wheel- and master-cylinder repair, hydraulic bleeding, pedal adjustment, the 178 mm parking brake, and exhaust-brake diagnosis. The steering and suspension volume covers pump pressure testing and bleeding, manual and power steering gear unit repair, linkage and column replacement, alignment checks, leaf-spring service, and wheel balancing.

The cab volume states that its procedures apply to Q Series bodies unless otherwise noted. It distinguishes rear cab mounts with and without rubber bushings and includes complete cab removal. Heating coverage is limited to the heater and ventilation system; there is no refrigerant-system repair chapter. The seat-belt volume covers belt and buckle removal and installation, but it does not include an airbag diagnostic or repair section.

Electrical diagnosis is split into dedicated LHD and RHD books. Named schematics include the Start and Charging circuit, QOS II system circuit, Exhaust Brake circuit, Engine Stop circuit, and the engine manual's EGR System wiring diagram. Lighting, wiper/washer, horn, backup warning, meter, heater, and fuel-heater circuits receive the same parts-location, connector, and circuit-diagram treatment.

Representative factory tools include the injection-nozzle tester 5-8840-9016-0, static timing gauge adapter set 5-8840-2834-0, power-steering pressure gauge 5-8840-0162-0, and transmission anti-lash plate installer 5-8840-2044-0. Repair cautions are equally specific: the transmission must not hang unsupported from the clutch during removal, or the clutch assembly can be damaged. The turbocharger section warns that incorrect servicing can damage pistons, valves, and cylinder liners.

PDF Set Makeup

1,332 PDF pages total — Engine: 332 pages; Brakes: 74; Cab and Chassis Electrical (LHD): 212; Cab and Chassis Electrical (RHD): 216; Frame and Cab: 84; General Information/Maintenance: 30; Heating and Ventilation: 40; JC52 Manual Transmission and Clutch: 106; Propeller Shaft and Axle: 106; Seat Belt: 14; Steering, Suspension, Wheels and Tires: 118.

OEM manual numbers printed on the covers are LG4JB-WE-1111, LGBRK-WE-1111, LGCEL-WE-1111LH, LGCEL-WE-1111RH, LGFRM-WE-1111, LGGEN-WE-1111, LGHAC-WE-1111, LGJC52-WE-1111, LGPRO-WE-1111, LGSRS-WE-1111, and LGSTG-WE-1111.

Engine rebuilding, turbocharger repair, brake work, cab removal, and electrical testing should be performed with the specified support equipment, measuring tools, and safety procedures; the manual itself treats servicing as work for qualified service personnel.