Case IH 956, 1056, 956XL, and 1056XL Workshop Manual D-155 – DT-402 Engine Service (P/N 1 091 624 R2, 1 091 627 R2)

This 886-page PDF is a scanned workshop-manual set for Case IH/J.I. Case 956, 1056, 956XL, and 1056XL tractors. It is not an engine-only publication. The 16 J.I. Case/Tenneco service sections date from 1986-1987 and cover naturally aspirated and turbocharged Neuss diesel engines, fuel injection, transmission, mechanical front drive, hydraulic lift, XL cab service, and air conditioning.

• Engine overhaul and testing covers the cylinder block and head, valve gear, camshaft and idler gear, crankcase, crankshaft and balance gear, pistons, sleeves, connecting rods, flywheel, lubrication, oil and water pumps, timing gear train, valve-lash adjustment, and engine performance checks.
• Fuel-system and turbocharger repair includes Bosch VA/CR and VE/F injection-pump operation, removal, bench overhaul, aneroid service, idle and power-output adjustment, on-engine testing, flange- and crab-mounted nozzles, and AiResearch and KKK/Schwitzer turbocharger service. It also covers cleaning the air-induction system after a compressor failure.
• Electrical equipment service covers DC generators, alternators with mechanical or transistorized regulators, JD- and JF-series starting motors, troubleshooting, MFWD relays and switches, and brake-light switch adjustment.
• Transmission service details removal and installation, shifter mechanisms, gearshift and speed-range units, rear countershaft and reverse idler gear, synchronized and non-synchronized speed reducers, differential and differential lock, PTO, and pressure-feed lubrication.
• Mechanical front-drive coverage includes the steering cylinder, axle removal, front drive shaft and center-bearing alignment, transfer gearbox and clutch service, accumulator, filter and shift solenoid, APL 335/345 differential and drive-pinion setup, and final-drive repair.
• Hydraulic diagnosis and repair covers draft and position control, lift disassembly, control-valve inspection, rockshaft and piston service, lower-link sensing adjustment, auxiliary valves, troubleshooting charts, and pressure, pilot-stream, relief-valve, and lift-capacity tests.
• XL cab and air-conditioning sections document cab tilting, service in place or tilted, cab removal and installation, tractor splitting, glass service, linkage adjustment drawings, A/C electrical circuits, performance and pressure diagnosis, leak testing, discharging, purging, evacuating, charging, and flushing.

Coverage and Configuration Details

The shared engine publications cover D-155, D-179, D-206, D-239, D-246, D-268, D-310, D-358, DT-239, DT-358, and DT-402 engines. This is the scope of the Neuss engine sections, not a claim that every listed engine was fitted to every 956 or 1056. Tractor-specific chapters identify the 956, 1056, 956XL, and 1056XL and, where assemblies are shared, also reference related 955/1055 and B-family tractors.

Variant tables separate standard and heavy-duty transfer gearboxes, 30/40 km/h versions, APL-330/335/345 axle pairings, and DZ-400 versus DZ-150 differential designs. The XL Control Centre and air-conditioning chapters are XL-specific, and the A/C procedures are written for the original R-12 system. Front-axle repair is for mechanical front-drive APL units. Dedicated full chapters for service-brake overhaul, the 2WD front axle, rear final drives, and hydrostatic power steering are not part of this set; the hydraulic section refers to a separate steering publication.

Page breakdown: one-page cover; Basic Engine, 105 pages; Fuel System and Turbochargers, 328; Electric Equipment, 48; MFWD electrical controls, 11; steering cylinder, 15; transmission, 79; seven MFWD axle and drive sections, 120; hydraulics, 63; XL Control Centre, 58; air conditioning, 58.

Engine publication numbers printed in the set are 1 091 624 R2 (Basic Engine), 1 091 627 R2 (Fuel System and Turbocharger), and 1 091 630 R2 (Electrical Equipment).

Factory Data, Tools, and Illustrations

Specification material includes torque tables, static injection-timing charts, crankcase-pressure and blow-by limits, compression and oil-pressure tests, wear limits and clearances, gear backlash and bearing preload, hydraulic pressure/flow checks, and A/C pressure-temperature and compressor-performance data.

Representative graphics include DT-358 longitudinal and cross sections, Bosch VA/CR and VE/F pump cutaways, transmission configuration cross-sections, transfer-gearbox clutch-stack layouts, hydraulic neutral/lift/lower circuit views, and the A/C wiring diagram with pressure-diagnosis charts. Tool coverage includes Bosch KDEP/FES pump fixtures, timing-indicator extension 1329 159C1, axle pullers and bearing tools, locally fabricated transfer-gearbox fixtures, hydraulic test gauges, and A/C manifold, vacuum, and leak-detection equipment.

The manual separates clutch-disc, spacer, axle, and speed-version data before transfer-gearbox assembly; mixing those specifications can make the MFWD clutch drag or slip and damage the pack. The A/C section requires contamination removal, flushing, and evacuation after compressor failure because debris or liquid refrigerant can damage compressor reed valves and pistons.

These repair procedures involve suspended components, tractor splitting, pressurized hydraulic oil, rotating driveline parts, and refrigerant. Use rated lifting and support equipment, relieve system pressure, isolate electrical power, and follow the manual's work-safety instructions.