BMW R26/R27 1955–1966 Repair & Parts Manual Set

The repair manual supplies the workshop procedures, while the illustrated catalog supports component identification through exploded views and part-number callouts. The price list adds descriptions and replacement notes for catalog entries.

The parts documents are later supplier references, separate from the BMW workshop publication. Their pricing and availability information is historical.

PDF Search, Navigation and Wiring Detail

Search and diagram detail: PDF text search is unavailable for the repair manual; both parts references have searchable text. None of the three PDFs has embedded bookmarks. Small terminal numbers in the wiring diagrams require zooming. The final English/Spanish sidecar continuation appears near the front of the repair file, at PDF p. 7.

The ZIP contains 268 pages across three printable PDF files. This total includes two additional front-matter pages in the repair PDF, plus the parts catalog’s cover, two introductory pages, two notes pages and one closing supplemental page.

Engine, Drivetrain and Sidecar Workshop Coverage

The following highlights are a selection of the contents, rather than a complete table of contents. Further topics include headlamp aiming and handlebar turn-signal removal.

• Engine repair: Step-by-step procedures for cylinder-head and valve work, cylinder and piston inspection, crankshaft installation, clutch and flywheel service, and oil-pump inspection.

• Timing and tune-up: Separate R26/R27 camshaft-drive, timing-chain and ignition-timing procedures, plus valve adjustment, carburetor cleaning, air-cleaner service and idle adjustment.

• Transmission overhaul: Foot-operated gear-change mechanism, primary and secondary shafts, selector adjustment, kickstarter, speedometer drive and neutral-indicator contact.

• Final drive: Propeller-shaft removal, seal and bearing service, matched pinion-and-crown-wheel identification, shim selection, backlash measurement and tooth-contact checks.

• Wheels and suspension: Wheel-bearing service, brake-lining replacement, wheel lacing and truing, suspension-unit disassembly, front swing-arm service and fork removal.

• Electrical diagnosis: Separate R26 and R27 wiring diagrams, charging-system tests, and fault charts for ignition, lighting and intermittent electrical faults.

• Sidecar conversion: BMW “Standard” sidecar attachment, chassis changes, lighting connections, alignment, hydraulic-brake filling and bleeding, and brake-sequencing adjustment.

The workshop manual was written for trained mechanics working in a properly equipped motorcycle shop; familiar operations are abbreviated, while special tools, measurements and assembly exceptions receive more detail.

Engine Inspection and Model-Specific Timing

Cylinder-head work extends to valve-guide replacement, valve-seat replacement and seat machining with Hunger equipment. Cylinder and piston sections explain measurement locations, assembly clearances and oversize selection.

For crankshaft or connecting-rod bearing defects, the manual recommends replacement crankshaft assemblies because of the bearing-fit and crankshaft-truing requirements. Its piston-installation caution identifies damaged piston-pin retaining clips as a cause of piston failure.

Separate camshaft and timing-chain indexing illustrations distinguish the two engine builds, helping prevent use of one model’s timing references on the other. The R27 chain adjuster is also described as a possible retrofit during R26 repair.

Ignition coverage includes stationary-engine checks and running-engine checks with a timing light. Carburetor troubleshooting relates an unsatisfactory idle to throttle-slide wear, intake sealing, valve-guide wear, compression and ignition faults.

Gearbox Removal and Final-Drive Setup

The R27 frame-number break determines whether direct gearbox removal under D3 or the engine-transmission-block procedure D5 applies. Internal transmission work includes selector-fork alignment, shaft end-play measurement and neutral-contact adjustment.

Final-drive instructions connect the stamped gear-set identification and pinion mounting-distance corrections with shim selection. Gear-contact illustrations distinguish acceptable contact from patterns requiring correction.

The assembly cautions explain how unprotected seal lips can be damaged and why the housing cover must fit without forcing it. Taper-roller bearing races and rollers must remain as matched sets during rear swing-arm and wheel-bearing service.

Chassis Service and Sidecar Installation

Suspension coverage includes spring and shock-absorber checks, steering-head bearing adjustment and front swing-arm bearing setup. Wheel lacing and truing are accompanied by spoke-position references and brake-drum inspection guidance.

Sidecar conversion extends beyond attachment hardware. It covers the final-drive and speedometer changes, suspension repositioning, heavier rear springs, handlebar and stand-stop changes, toe-in and camber setup, and coordination of sidecar braking with the motorcycle’s rear brake. The manual assigns this conversion work to a specialist BMW workshop.

Engine, wheel, brake, steering, frame, and sidecar work directly affects safe vehicle operation. Use proper supports and personal protective equipment, isolate fuel and electrical systems where required, follow the complete manual procedure, and verify all braking, steering, wheel, and drivetrain functions before returning the motorcycle to service.

Charging Tests, Fault Charts and Workshop Tools

Electrical information distinguishes the R27 generator and Bosch Z regulator from the R26 generator with Bosch F regulator. Battery, horn, switch, neutral-indicator and sidecar-lighting information accompanies terminal identification and wiring references.

Testing covers no-load and load-regulating voltage, cut-in voltage, reverse current, removed-armature faults and field-coil faults. The manual reserves regulator adjustments and defective field-coil replacement for Bosch service facilities.

Visual references include timing-chain indexing views, clutch and flywheel photographs, transmission-shaft and selector layouts, final-drive contact patterns, wheel-spoke references and sidecar mounting and brake illustrations, numbered through Fig. 235.

Tool listings identify the Matra 311 flywheel puller, Matra 529 clutch-centering arbor, 5042 final-drive tooth-play fixture, 5094 suspension compressor, 5096 neutral-contact gauge and 5098/4 spoke-fitting gauge. Technical-data and fits-and-clearances tables provide torque specifications, lubrication data and wear limits alongside the procedures.

Examples of Valve and Oil-Pump Clearances

For both engines, the technical-data table lists cold running valve clearances of 0.15 mm intake and 0.20 mm exhaust. Separate checking settings are given for camshaft timing.

Oil-pump inspection specifies gear-tooth flank clearance of 0.03–0.05 mm and lateral gear clearance in the housing of 0.01–0.04 mm.