Comprehensive factory workshop manual for the Triumph Herald 1200 and 12/50 (1959-1971). Provides complete engine rebuild procedures, twin SU carburetor tuning, gearbox and overdrive service, swing-axle suspension overhaul, brake system repair, steering rack rebuild, and Lucas electrical system diagnostics. The definitive resource for Triumph Herald owners, classic car restorers, and specialist mechanics.
1959-1971 Triumph Herald 1200 12/50 Service Repair Workshop Manual PDF
VEHICLE/EQUIPMENT INTRODUCTION:
The Triumph Herald was a small classic British car produced by the Standard-Triumph Company from 1959 to 1971. Designed by the renowned Italian stylist Giovanni Michelotti, the Herald featured a distinctive appearance with a two-door saloon, convertible, coupe, and estate body style. The unique chassis design featured a separate backbone frame that allowed the body to be unbolted from the chassis, a feature that made panel replacement and painting straightforward. The 1200 model featured a 1147cc inline-four OHV engine, while the performance-oriented 12/50 variant added a tuned engine with a higher compression ratio and improved carburetion. The all-independent swing-axle suspension provided a remarkably comfortable ride for a small car of the era, and the mechanically operated disc brakes on the front wheels were advanced for the segment. Today, the Herald is a cherished classic with a passionate owner club community supporting preservation and restoration.
SERVICE & REPAIR SCOPE:
- Engine overhaul for 1147cc OHV inline-four: rebore, regrind, and rebuild procedures
- Cylinder head decarbonizing and valve seat reconditioning
- Twin SU carburetor removal, strip, clean, and jet setting
- Engine oil pump replacement, pressure relief valve adjustment
- Clutch cable adjustment and driven plate replacement
- Four-speed gearbox with optional overdrive: synchromesh repair and bearing preload
- Propeller shaft universal joint replacement and center bearing inspection
- Rear differential and swing-axle overhaul: crown wheel setup and axle shaft seal replacement
- Front suspension: wishbone, king pin, and trunnion bearing replacement
- Rear swing axle spring and rubber spring unit service
- Front Girling disc brake caliper rebuild and pad replacement
- Rear drum brake shoe replacement and wheel cylinder overhaul
- Steering rack overhaul and column universal joint inspection
- Lucas electrical system troubleshooting: generator, distributor, and voltage regulator
- Wiring harness inspection, headlamp beam alignment, and earth strap repair
- Heater and ventilation system service
TECHNICAL SPECIFICATIONS:
- Engine: 1147cc inline-four, OHV, single cam-in-block
- Herald 1200: 48 bhp
- Herald 12/50: 61 bhp with higher compression and twin SUs
- Carburetors: Twin SU HS2
- Gearbox: 4-speed manual, Laycock overdrive optional
- Front suspension: Independent with king pin and coil springs
- Rear suspension: Swing-axle with transverse leaf spring
- Front brakes: 8.4-inch Girling disc
- Rear brakes: 7-inch drum
- Steering: Rack and pinion
- Wheelbase: 85 inches
DIAGNOSTIC INFORMATION:
- Engine oil pressure below 40 psi: inspect oil pump gear wear, main bearing clearance, and pressure relief valve
- Carburetor dashpots leaking: check dashpot damper oil level, inspect piston diaphragm for splits and tears
- Gearbox jumping out of second: worn synchromesh baulk ring or detent spring issue
- Rear end hop on bumpy roads: inspect rear rubber spring units, check swing axle pivot bushes, add anti-roll bar if not fitted
- Front brake judder under braking: inspect disc for warping, pad bedding, check trunnion bearing play
- Steering free play excessive: inspect rack end bushes, check rack pinion mesh adjustment, examine steering column U-joints
- Generator fails to charge: inspect cut-out relay contacts, clean voltage regulator contacts, test armature output
- Overdrive not engaging: test solenoid wiring, check operating switch, inspect oil level in overdrive unit
ILLUSTRATIONS & DIAGRAMS INCLUDED:
- Engine cross-section with bearing clearance specifications
- Twin SU carburetor exploded drawing with jet height adjustment
- Gearbox and overdrive assembly with torque data
- Rear swing-axle and rubber spring unit diagram
- Brake hydraulic system layout
- Full Lucas 12-volt wiring schematic
- Chassis frame with body mounting bolt sequence
- Suspension geometry with trunnion and king pin detail
COMPATIBILITY:
- Covers Triumph Herald 1200 1959 to 1971
- Covers Triumph Herald 12/50 performance variant
- All body styles: saloon, coupe, convertible, estate
- File format: Searchable PDF
FILE PROPERTIES:
- Format: Searchable PDF
- Language: English
- Delivery: Instant digital download
- Access: Download anytime after purchase
1959-1971 Triumph Herald 1200 12/50 Service Repair Workshop Manual PDF
VEHICLE/EQUIPMENT INTRODUCTION:
The Triumph Herald was a small classic British car produced by the Standard-Triumph Company from 1959 to 1971. Designed by the renowned Italian stylist Giovanni Michelotti, the Herald featured a distinctive appearance with a two-door saloon, convertible, coupe, and estate body style. The unique chassis design featured a separate backbone frame that allowed the body to be unbolted from the chassis, a feature that made panel replacement and painting straightforward. The 1200 model featured a 1147cc inline-four OHV engine, while the performance-oriented 12/50 variant added a tuned engine with a higher compression ratio and improved carburetion. The all-independent swing-axle suspension provided a remarkably comfortable ride for a small car of the era, and the mechanically operated disc brakes on the front wheels were advanced for the segment. Today, the Herald is a cherished classic with a passionate owner club community supporting preservation and restoration.
SERVICE & REPAIR SCOPE:
- Engine overhaul for 1147cc OHV inline-four: rebore, regrind, and rebuild procedures
- Cylinder head decarbonizing and valve seat reconditioning
- Twin SU carburetor removal, strip, clean, and jet setting
- Engine oil pump replacement, pressure relief valve adjustment
- Clutch cable adjustment and driven plate replacement
- Four-speed gearbox with optional overdrive: synchromesh repair and bearing preload
- Propeller shaft universal joint replacement and center bearing inspection
- Rear differential and swing-axle overhaul: crown wheel setup and axle shaft seal replacement
- Front suspension: wishbone, king pin, and trunnion bearing replacement
- Rear swing axle spring and rubber spring unit service
- Front Girling disc brake caliper rebuild and pad replacement
- Rear drum brake shoe replacement and wheel cylinder overhaul
- Steering rack overhaul and column universal joint inspection
- Lucas electrical system troubleshooting: generator, distributor, and voltage regulator
- Wiring harness inspection, headlamp beam alignment, and earth strap repair
- Heater and ventilation system service
TECHNICAL SPECIFICATIONS:
- Engine: 1147cc inline-four, OHV, single cam-in-block
- Herald 1200: 48 bhp
- Herald 12/50: 61 bhp with higher compression and twin SUs
- Carburetors: Twin SU HS2
- Gearbox: 4-speed manual, Laycock overdrive optional
- Front suspension: Independent with king pin and coil springs
- Rear suspension: Swing-axle with transverse leaf spring
- Front brakes: 8.4-inch Girling disc
- Rear brakes: 7-inch drum
- Steering: Rack and pinion
- Wheelbase: 85 inches
DIAGNOSTIC INFORMATION:
- Engine oil pressure below 40 psi: inspect oil pump gear wear, main bearing clearance, and pressure relief valve
- Carburetor dashpots leaking: check dashpot damper oil level, inspect piston diaphragm for splits and tears
- Gearbox jumping out of second: worn synchromesh baulk ring or detent spring issue
- Rear end hop on bumpy roads: inspect rear rubber spring units, check swing axle pivot bushes, add anti-roll bar if not fitted
- Front brake judder under braking: inspect disc for warping, pad bedding, check trunnion bearing play
- Steering free play excessive: inspect rack end bushes, check rack pinion mesh adjustment, examine steering column U-joints
- Generator fails to charge: inspect cut-out relay contacts, clean voltage regulator contacts, test armature output
- Overdrive not engaging: test solenoid wiring, check operating switch, inspect oil level in overdrive unit
ILLUSTRATIONS & DIAGRAMS INCLUDED:
- Engine cross-section with bearing clearance specifications
- Twin SU carburetor exploded drawing with jet height adjustment
- Gearbox and overdrive assembly with torque data
- Rear swing-axle and rubber spring unit diagram
- Brake hydraulic system layout
- Full Lucas 12-volt wiring schematic
- Chassis frame with body mounting bolt sequence
- Suspension geometry with trunnion and king pin detail
COMPATIBILITY:
- Covers Triumph Herald 1200 1959 to 1971
- Covers Triumph Herald 12/50 performance variant
- All body styles: saloon, coupe, convertible, estate
- File format: Searchable PDF
FILE PROPERTIES:
- Format: Searchable PDF
- Language: English
- Delivery: Instant digital download
- Access: Download anytime after purchase
