Triumph GT6 & Vitesse Workshop Manual Collection, 1966–1973

The factory workshop manual supplies the GT6/Vitesse repair procedures, while the other publications address their named vehicles, component systems, competition preparation, or historical background. The two general Triumph tuning books substantially overlap.

Supplement dependencies: The TR250 supplement calls for the TR4 and GT6 workshop manuals; the GT6 manual is included, but the TR4 base manual is not. The Spitfire/TR4A emission supplement supplements the Spitfire Workshop Manual P/N 511243 and TR4A Workshop Manual P/N 510322, neither of which is included.

PDF Search, Bookmarks, and Diagram Detail

Text search: Search is unavailable in the GT6, TR250, Lucas injection, overdrive, TR maintenance, Spitfire competition, and Spitfire/TR4A emission-supplement PDFs. The two general Triumph tuning books are partly searchable; the remaining 14 PDFs contain searchable text.

Navigation and small labels: Eight files include embedded bookmarks. Some emission-training bookmarks and additional entries in the general tuning books are unusable. Small wiring labels in the GT6 manual and TR250 supplement require zooming.

The ZIP contains 23 printable PDFs totaling 1,313 pages, including covers, eight blank pages in the GT6 manual, and one promotional closing page in the Spitfire competition booklet. A readme and legacy PDF-reader installer are also included.

Engine, Drivetrain, and Electrical Repair

These selected coverage highlights outline the main workshop material rather than reproduce the complete contents. Further topics include exhaust-system removal and dust-and-water sealing of body joints.

• Engine overhaul: Step-by-step procedures cover engine and gearbox removal, dismantling, crankshaft inspection, piston installation, cylinder-head reconditioning, valve timing, and reassembly.

• Fuel and emissions: Stromberg carburetor rebuilding and balancing, fuel-pump service, crankcase ventilation, evaporative-loss testing, and running-on control diagnosis.

• Clutch and transmission: Hydraulic-cylinder repair, clutch service, gearbox dismantling, synchromesh checks, and overdrive hydraulic and electrical testing.

• Rear axle and suspension: Differential setup, pinion-bearing preload, crownwheel backlash, rear-hub work, Rotoflex couplings, and variant-specific suspension procedures.

• Brakes and steering: Bleeding, master-cylinder overhaul, disc and drum brake service, Powerstop servo testing, tandem braking, and steering-rack adjustment.

• Electrical diagnosis: Model-specific wiring diagrams, starter and charging-system tests, distributor checks, instrument testing, and hazard-warning circuits.

• Body and chassis: Body removal, chassis-dimension checks, bonnet and door adjustment, glazing, heater service, and interior-trim removal.

The factory workshop material was written for Standard-Triumph distributors and dealers and requires specialist tools for some operations; the Spitfire/TR4A supplement reserves its emission-service procedures for authorized Triumph dealers.

Overhaul Measurements and Variant Selection

Engine and differential work: The repair sections pair dismantling and assembly instructions with dimensions, clearances, tightening torques, and inspection criteria. Crankshaft end-float checks, valve-seat work, pinion-height adjustment, and differential shim calculations show the depth of the workshop coverage.

Overdrive diagnosis: The GT6/Vitesse section connects solenoid and operating-valve checks with hydraulic-pressure testing and pump diagnosis. A pump delivering oil does not, by itself, establish that operating pressure is correct.

The separate overdrive booklet concerns the earlier Vanguard, Renown, and TR2 installations. Its settings should be kept with those applications.

Suspension, Bodywork, and Wiring References

The rear-axle and suspension sections distinguish swing-axle arrangements from the lower-wishbone and Rotoflex layouts. Dimensional illustrations support accident-damage assessment, while the chassis and body sections address mounting points, panel alignment, and sealing locations.

Commission-number-specific wiring diagrams let you select the appropriate circuit before tracing a fault. GT6 Mk. 3 diagrams distinguish early and later KE installations, Swedish-market wiring, and successive USA-market KF configurations.

Illustration examples include the Coolant Circulation Diagram, Exploded Arrangement of Overdrive Unit, Diagram for Calculating Shim Pack Thicknesses, and GT6 Mark 3—U.S.A. Market Only Wiring Diagram.

Spitfire and TR4A Emission Supplement

This factory supplement addresses the S.U.-carburetor emission systems developed for the US requirements described in the publication. Its introduction identifies specifications AUD 284 and AUD 285; the servicing section specifically identifies N.A.D.A. specification AUD 285 and prohibits substitution with non-emission-specification carburetors.

Model differences: Spitfire changes include the emission cylinder head, Stellite-faced exhaust valves, revised camshaft timing, extended-range distributor, crankcase emission-control valve, and Champion UN12Y plugs. TR4A changes center on carburetor needles, main jets, dampers, throttle-disc poppet valves, and distributor characteristics.

The model data identifies distributor assemblies 214799 for the Spitfire and 214805 for the TR4A, DD and QW needles respectively, and AUC 8103 dampers.

Service depth: Procedures cover cylinder-compression comparison, distributor maintenance and performance testing, dynamic ignition timing, basic and complete carburetor synchronization, and exhaust-gas mixture checks. Reconditioning covers the float chamber, throttle disc, suction chamber, piston, needle, jet, and linkage, plus crankcase-valve cleaning and reassembly.

Its 20 numbered illustrations include Checking Piston Drop and Crankcase Emission Control Valve. Exploded views identify the individual linkage, jet, float, diaphragm, and restrictor components.

Periodic information includes initial distributor checks at 1,000 miles, distributor attention at 6,000-mile intervals, timing checks at 12,000 miles, and carburetor rebuilding or exchange around the 48,000/50,000-mile service point.

The carburetor needle must not be bent or scratched, and the original suction-chamber and throttle-component orientation matters during reassembly. Overtightening the flexible jet-tube connection can compress its gland incorrectly and cause fuel leakage.

Many tuning checks require the engine to operate at normal temperature with ignition and exhaust-gas test equipment connected. Appropriate workshop precautions around hot components, rotating engine parts, fuel, and the ignition system remain necessary.

Injection, Tuning, and Supporting References

The Lucas Mk. II manual covers metering-distributor and mixture-control-unit service, pump and motor checks, injector testing, and bench calibration. The emission-training notes explain Stromberg operation, charcoal-canister systems, thermostatic controls, anti-run-on operation, and symptom-based fault finding.

The competition books discuss engine preparation, lubrication changes, cylinder-head development, transmission modifications, suspension, and brakes. These are modification references rather than substitutes for the applicable factory procedures.

The Weber guide uses Pinto jetting examples, and the B20 carburetor descriptions explain their own installations. They provide background reference material rather than GT6-specific factory settings. The parts catalog, buyer's guide, production notes, and histories serve separate parts-identification and ownership-reference purposes.

Valve-Clearance and Emission-Setting Examples

For the GT6/Vitesse engines, the general specification tables list a cold inlet and exhaust valve clearance of 0.010 in. and a spark-plug gap of 0.025 in. These accompany the valve-adjustment and ignition-service material.

In the separate Spitfire Mk. 3/TR4A S.U. supplement, warm-idle CO is specified at 3.5–4.5% for both installations, alongside model-specific distributor advance curves and mixture-setting data.