Cub Cadet 72, 104, 105, 124 & 125 Tractor Service Manual – 1967–1969 (P/N GSS-1398)

International Harvester’s September 1969 Blue Ribbon Service Manual (P/N GSS-1398) covers Cub Cadet tractors 72, 104, 105, 124, and 125 and selected IH attachments.

PDF Format and Page Navigation

Navigation and diagram detail: The PDF has numbered bookmarks for each page. Text search is unavailable. Small terminal labels in the electric-start wiring diagram and oil-passage labels in the hydrostatic foldout are easier to read when zoomed in.

The download is one printable English PDF with 121 pages, including the front and back covers, a blank service bulletin record sheet, and the hydrostatic transmission foldout.

Tractor Repair and Attachment Service

The bullets give a selection of the service procedures. The manual also covers front wheel bearing replacement and recoil starter overhaul.

• Kohler engine overhaul: Engine removal, teardown, cylinder reboring, crankshaft and connecting rod inspection, piston and ring service, valve and guide work, camshaft and seal installation, and reassembly.
• Fuel and governor service: Carburetor teardown, cleaning, float setting, and mixture adjustment, with separate governor and throttle linkage procedures for Model 72 and the larger tractors.
• Ignition and charging: Magneto output, breaker points, condenser testing, ignition timing, starter-generator brush service, and cut-out relay and voltage regulator adjustments.
• Gear drive: Tractor splitting and recoupling, clutch and reduction-drive repair, transmission and differential teardown, rear axle and brake service, and optional creeper drive overhaul.
• Hydrostatic drive: Unit removal and installation, charge pump and valve service, internal pump and motor repair, differential work, brake and neutral adjustments, and troubleshooting.
• Steering and PTO: Steering gear overhaul, front axle service, front PTO clutch repair, and separate rear PTO illustrations for Model 72 and Models 104 and 124.
• IH attachments: Mower removal, spindle repair, blade sharpening, belt adjustment, and deck leveling. Snow thrower coverage is limited to the gearbox. The International 1 rotary tiller section covers tine timing and gearbox service.

International Harvester wrote this manual for its dealers and factory-trained service technicians, and the overhaul procedures assume access to shop equipment such as presses, pullers, and measuring tools.

Engine Inspection and Electrical Diagnosis

Engine variants: Model 72 uses the K-161S with electric start or the K-161T with a recoil starter. Models 104 and 105 use the K-241AS, while Models 124 and 125 use the K-301AS. The K-161 valve procedure addresses clearance at the valve stems, while the K-241 and K-301 use adjustable tappets. A separate compression check for Automatic Compression Release engines helps avoid misleading readings at low cranking speeds.

Inspection and assembly: Engine tables give clearances, wear limits, and component torques for overhaul work. The crankshaft seal procedures identify the FES 54-4 rear seal protector, FES 54-5 front seal protector, and FES 54-6 seal driver. Incorrect orientation of the breather plate or reed can cause oil leakage.

Wiring and test coverage: Separate diagrams show magneto ignition, lighting, and electric-start wiring, including terminal and wire-color references for the starting circuit. The manual covers starter-generator brush inspection and replacement and refers further bench testing to the separate GSS-1052-C service manual.

Gear Drive, Hydrostatic Service, and PTO

Gear drive and final drive: For Models 72, 104, and 124, the manual shows gear and spacer order, differential bearing preload, bevel gear backlash, and tooth contact patterns. The rear axle carrier uses a bronze bushing on Model 72 and a needle bearing on Models 104, 105, 124, and 125. The reduction-drive section shows the OTC-950 puller, and the front PTO clutch section shows the adjustment gauge supplied with the clutch disc repair kit.

Hydrostatic repair: For Models 105 and 125, the exploded view and oil-flow foldout show how the variable-displacement pump, fixed-displacement motor, and control linkage work together. The manual illustrates charge pumps with and without a port plate, gives dimensions for a holding fixture, and covers rotor, piston, slipper, swash plate, center section, and bearing inspection. The two-notch pump valve plate and four-notch motor valve plate have distinct locations, and scoring on the valve faces can reduce pump efficiency.

Troubleshooting: For a tractor that barely moves in either direction, the manual helps narrow the fault to the suction circuit, mechanical drive, control linkage, or charge pump and valves. The hydrostatic tables also give spring test data, assembly torques, and wear limits, with fluid requirements covered in the service procedures.

Tractor splitting, hydrostatic repair, and PTO or clutch work involve heavy assemblies, rotating components, and hydraulic oil. The service procedures call for battery isolation, blocking, lifting support, and careful cleanliness where applicable.

Hydrostatic Charge Pressure and Slipper Tolerance Examples

For Models 105 and 125, the charge pump specification is 70–120 psi at rated speed.

The pump and motor slippers have a minimum thickness of 0.121 inch. Within a block assembly, all slippers must be within 0.002 inch of one another.