1985 Bolens 1886s-05, 2086, 2087, 2288, 2289, 2388s, 2389, 2389s Service Manual (P/N 552665-5)

The official 107-page OEM publication (P/N 552665-5, Revision 3/85) is the authoritative factory reference for maintaining 1985 Bolens Large Frame tractors.

• Covers 1886s, 2086, 2087, 2288, 2289, 2389, and 2388s models, including gas and diesel powertrain variants.
• Identifies specific tractor and engine configurations including HT 18, HT 20, HT 22, HT 23, HDT 1000, Kohler, Teledyne Wisconsin, and Ducati.
• Details specific subsystems and attachments such as power steering units, two-speed transaxles, charge pumps, implement relief valves, seat interlock switches, preheat circuits, rotary mowers, snow throwers, and garden tillers.
• Features 38 exploded-view diagrams, 16 wiring schematics, and 3 comprehensive torque specification tables.
• Documents engine, chassis, electrical, and hydraulic system specifications.

Mechanical and Electrical Systems Overview

When you have a Bolens Large Frame on the lift, you need exact routing and diagnostic data. This PDF maps out the core systems. It starts with extensive electrical diagrams, light circuit diagrams, and start-run circuit drawings. These are broken down by the specific serial number changes found across the lineup, saving you time when tracing a dead short. Working on vintage heavy equipment presents serious hazards, especially regarding pressurized hydraulic lines and heavy rotating components. Reviewing factory-approved diagnostic sequences reduces the risk of injury or parts damage before turning a wrench.

The documentation moves into the hydrostatic transmission, detailing the operating principles for both Sundstrand and Eaton units using hydrostatic transmission flow charts. It covers the factory-recommended procedures for removal, installation, and internal disassembly of individual pumps, motors, and center sections. Executing a major hydrostatic overhaul or a complete two-speed transaxle repair usually forces an expensive trip to a specialized agricultural shop. However, this manual provides the step-by-step instructions to separate the pump and motor sections, rebuild the charge pump, and properly align the axles, keeping the labor entirely in-house. Further sections map out the fuel system, noting carburetor adjustment parameters, fuel filter maintenance, and air cleaner service. You will also find chassis coverage detailing front axle alignment, turning radius settings, disc brake adjustments, and P.T.O. belt tensioning. The hydraulic section rounds this out with testing parameters, control valve breakdowns, and oil cooler routing for heavy-duty applications.

Specification and Reference Data

Bypassing generic specifications in favor of these exact Bolens factory tolerances speeds up turnaround times and prevents component binding during a mechanical repair. This reference delivers the exact clearances, fluid capacities, and torque settings required to return these classic agricultural units to original equipment standards. Visual aids like maintenance charts, lubrication charts, and transaxle exploded views provide clear guidance at the bench. The transmission oil capacity for the hydrostatic unit is clearly documented at 10 quarts (9.5 L). It notes that valve clearance checks for Mitsubishi diesel engines are required every 50 hours of operation. When bolting the drivetrain back together, the main transaxle assembly bolts demand exactly 30 ft. lbs. (40 Nm) of torque. You also get specific gear data, like the 55-tooth cluster and 15-tooth pinion configuration used for the transaxle, alongside the 7-quart (6.6 L) radiator capacity for the Mitsubishi-powered 2388s.