1983–1999 Bolens QS-16, QT-16, QT-17 & 1900 Series Tractor Service Manual (P/N 552974-2)

Bolens factory service manual Form 552974-2 (4/83), superseding 552974-1, covers the 1983–1999 QS-16, QT-16, QT-17, and 1900 Series tractors, including models 1660, 1666, and 1966.

Text search and wiring detail: PDF text search is unavailable. Two basic bookmarks open the added front page and manual cover; there are no chapter bookmarks. Small labels in the denser wiring diagrams require zooming.

• Electrical diagnosis: Serial-specific wiring diagrams, starter and charging circuits, seat-switch and PTO circuits, plus battery, solenoid, and switch tests.

• Hydrostatic drive: Sundstrand internal repair, Eaton removal and reinstallation, and transaxle assembly, bearing installation, and clearance checks.

• Hydraulic lift: Eaton and Sundstrand pressure tests, implement relief-valve inspection, lift-cylinder repair, and control-valve seal replacement.

• Engine and fuel systems: Onan and Kohler engine removal, troubleshooting, carburetor adjustments, and fuel-filter and air-cleaner service.

• Chassis and PTO: Steering gear rebuilding, wheel alignment, disc brakes, interlock adjustments, attachment-drive belts, and electric clutch/brake diagnosis.

• Attachments: Mower deck leveling, gear-case and spindle repair, plus snow thrower and tiller drive-system disassembly and reassembly.

This manual is suited to mechanics comfortable with hydraulic pressure testing, electrical meters, and checking gear clearances during assembly.

Engine Variants and Repair Scope

Model 1666 covers the Onan BF/MS-powered QT-16 at S/N 0100101–0599999 and the Kohler KT17QS-powered QT-17 from S/N 0600101. The QS-16 uses the Kohler K341AQS; model 1966 uses the KT19QS.

Engine coverage includes mount identification and removal/reinstallation, with carburetor adjustments separated by engine family. Internal engine overhaul requires separate engine documentation; the Onan repair reference is Form 8965-250, which is not included.

Hydrostatic Drive and Hydraulic Lift

The 1666 transmission changes from Sundstrand to Eaton Model 11 at S/N 0500101, before its engine change. Matching both serial breaks helps avoid choosing the wrong pressure-test procedure or lubricant specification.

Sundstrand repair extends to the charge-pump gerotor, cylinder blocks, swashplate, valve plates, and motor section, supported by a Hydrostatic Exploded View. Eaton internal overhaul requires the separate Eaton Service and Repair Manual; this publication covers identification, testing, and removal/reinstallation.

Hydraulic power-lift drawings show the Sundstrand and Eaton circuits. Cylinder teardown covers piston-rod seals, while control-valve repair covers spool seals and the detent. The spool and body are matched; damage to either calls for replacement of the valve assembly.

The Sundstrand installation notes warn that protective tape left under the oil filter blocks oil flow and can damage the hydro. The hydrostatic transmission flow chart listed in the contents is absent from this PDF.

Transaxle, Steering, Brakes, and PTO

Transaxle assembly drawings identify bull gears, carrier assemblies, thrust bearings, shims, and oil seals. Clearance checks cover axle and cluster-gear end play and bevel-gear backlash, with bearing and seal installation guidance.

Steering-sector repair includes bushing replacement and shim selection. Brake linkage adjustment explains the neutral interlock, while PTO coverage separates the QS-16 mechanical drive from the QT/1966 electric clutch/brake.

PTO reference data distinguishes early and later clutch specifications. The clutch/brake cautions identify brake-flange damage from overtightened locknuts.

Mower, Snow Thrower, and Tiller Repair

Mower gear-case procedures distinguish models 19209, 19210, and 19211 from 19212, with Gear Case Breakdown and Spindle Breakdown drawings. Snow thrower coverage adds chain tension, auger-bearing removal, and gearbox service; tiller coverage includes chain-drive and tine-shaft assembly with backlash and end-play checks.

Reference data includes component torques, lubricant capacities, gear clearances, and electrical test values. Maintenance and lubrication charts cover cooling screens, spark plugs, filters, chassis pivots, and transmission fluids.

Before service, use lifting equipment rated for the tractor's weight and disconnect the battery to prevent accidental engagement.

PDF Contents and Pagination

This printable English manual has eight service groups and comes as a 94-page PDF: three original front-matter pages, 90 service pages, and one added front page. The service-page count already includes the eight-page attachment section and the duplicate of page 3-1; printed pages 3-3, 3-5, and 3-6 are absent.