Land Rover Series III
1973 Land Rover Series III 88-inch Petrol — Vehicle Identification
| Identification | Number / Detail | Source / Notes |
|---|---|---|
| Chassis / VIN | 90302754A | Solihull identification plate; also recorded on Australian compliance plate |
| Engine serial number | 90137598A | Stamped on engine block; 901 prefix denotes original 8:1 compression petrol engine |
| Engine block casting number | 541874 | Raised casting number |
| Cylinder head casting number | 568750 | Raised casting number on cylinder head |
| Body number | LRS 16954 | Pressed Metal Corporation, Sydney |
| Body serial number | 6816954 | Pressed Metal Corporation, Sydney |
| Australian compliance date | 08/1973 | Leyland Motor Corporation of Australia Ltd |
| Australian model designation | LAND ROVER 3ST | Australian compliance plate |
| Solihull model designation | LAND-ROVER 88 PETROL SERIES III | Manufacturer's identification plate |
| Item | Details |
|---|---|
| Model | Land Rover 88 Petrol, Series III |
| Manufacturer | Rover–British Leyland UK Ltd, Solihull, England |
| Chassis number | 90302754A |
| Australian compliance date | August 1973 (8/73) |
| Australian compliance plate manufacturer | Leyland Motor Corporation of Australia Ltd |
| Australian body manufacturer | Pressed Metal Corporation Ltd, Sydney |
| Body number | LRS 16954 |
| Body serial number | 6816954 |
| Seating capacity | 3 |
| Maximum laden weight | 2,020 kg (4,453 lb) |
| Maximum front axle weight | 830 kg (1,828 lb) |
| Maximum rear axle weight | 1,190 kg (2,625 lb) |
| Recommended maximum towing capacity | 2 tons |
| Australian Design Rules | 1, 6, 7, 8, 11, 12, 20 |
Land Rover Series III — 2¼-litre Petrol Engine Tuning Data
| Component | Specification | Value |
|---|---|---|
| Engine | Type | In-line four-cylinder, four-stroke, overhead valves |
| Capacity | 2,286 cm³ (139.5 cu in) | |
| Compression ratio — standard | 8.0:1 (engine number commencing 901) | |
| Firing order | 1–3–4–2 | |
| Compression pressure — 8:1 | 11.2 kgf/cm² (160 psi) | |
| Idling speed | 500 rev/min | |
| Fast idle setting | 1.40 mm (0.055 in) throttle butterfly clearance; 1,200 ± 50 rev/min | |
| Ignition timing and valves | 8:1 static timing | TDC with 90-octane fuel; 3° BTDC with 85-octane fuel |
| Timing marks | On crankshaft pulley | |
| Valve clearance — inlet and exhaust | 0.25 mm (0.010 in) | |
| Distributor | Make/type | Lucas 45D |
| Rotor rotation | Anti-clockwise | |
| Contact breaker gap | 0.36–0.40 mm (0.014–0.016 in) | |
| Condenser capacity | 0.2 microfarad | |
| Serial number | 5069 | |
| Centrifugal advance | 4500 rev/min | 38°–42° crankshaft angle |
| 3500 rev/min | 30°–34° | |
| 2500 rev/min | 22°–26° | |
| 1200 rev/min | 12°–16° | |
| 900 rev/min | 4°–12° | |
| 600 rev/min | 0°–4° | |
| Below 450 rev/min | No advance | |
| Vacuum advance | Starts | 89 mm (3.5 in) Hg |
| Finishes | 635 mm (25.0 in) Hg | |
| Spark plugs | 8:1 compression | Champion N12Y or Unipart GSP131 |
| NGK alternative (added) | NGK BP5E or BP5ES | |
| Electrode gap | 0.75–0.80 mm (0.029–0.032 in) | |
| Ignition coil | Make/type | HA12 |
| Primary resistance at 20°C | 3.0–3.5 ohms | |
| Consumption at idle | Approximately 2.0 amps | |
| Carburettor | Make/type | Zenith 36IV |
| Choke diameter | 27 mm | |
| Main jet | 125 | |
| Compensating (enrichment) jet | 150 | |
| Pump jet / needle valve | 65 (short stroke, outer hole) / 1.75 | |
| High-altitude carburettor jets | Main jet 120 | 1524–2133 m (5000–7000 ft) |
| Main jet 117.5 | 2133–2743 m (7000–9000 ft) | |
| Main jet 115 | 2743–3657 m (9000–12000 ft) | |
| Main jet 112.5 / slow-running jet 55 | 3657–4267 m / 2743–4267 m respectively |
Source: Land Rover Series III workshop manual, p. 05-1, Engine Tuning Data. Original ignition timing fuel octane figures are historical specifications and should not be equated directly with modern Australian RON ratings. Centrifugal advance figures are with vacuum advance disconnected.
Permanent Live Fuse Box
| Fuse pin | Description | Fuse |
|---|---|---|
| 1 | Horn relay feed | 10 A |
| 2 | Low beam relay feed | 15 A |
| 3 | Main beam relay feed | 15 A |
| 4 | Ignition switch feed | 5 A |
| 5 | Main beam flash/ interior lamp/ Dashcam + Batt | 10 A |
| 6 | Ignition relay feed | 25 A |
Ignition Live Fuse Box
| Fuse pin | Deutch connector pin | Description | Fuse |
|---|---|---|---|
| 1 | A1 | Headlamp switch pin 4 | 7.5 A |
| 2 | A2 | Blower | 10 A |
| 3 | A3 | Spare | |
| 4 | A4 | USB/ Auxiliary/ Voltage meter | 10 A |
| 5 | A5 | Alternator warning/ Oil pressure/ Voltage stabiliser | 5 A |
| 6 | A6 | Coil + | 5 A |
| 7 | B1 | Dashcam + Acc | 5 A |
| 8 | B2 | Horn trigger on stalk | 5 A |
| 9 | B3 | Wipac LED blinker | 7.5 A |
| 10 | B4 | Wipers and washer | 7.5 A |
| 11 | B5 | Reverse lamp feed | 5 A |
| 12 | B6 | Brake lamp feed | 5 A |
Torque Wrench Settings
| Component / fastener | kgf·m | lbf·ft |
|---|---|---|
| Engine — 2¼-litre 4-cylinder | ||
| Connecting rod cap nuts | 3.5 | 25 |
| Main bearing cap bolts — petrol engines, 3-bearing | 11.5 | 85 |
| Main bearing cap bolts — diesel engines | 13.8 | 100 |
| Cylinder head bolts — petrol engines, 5/16 in. UNF | 2.4 | 18 |
| Cylinder head bolts — petrol engines, 1/2 in. UNF | 8.9 | 65 |
| Cylinder head bolts — diesel engines, 5/16 in. UNF | 2.4 | 18 |
| Cylinder head bolts — diesel engines, 1/2 in. UNF | 12.5 | 90 |
| Rocker shaft bolts — petrol engines, 5/16 in. UNF | 2.4 | 18 |
| Rocker shaft bolts — petrol engines, 1/2 in. UNF | 8.9 | 65 |
| Rocker shaft bolts — diesel engines, 5/16 in. UNF | 2.4 | 18 |
| Rocker shaft bolts — diesel engines, 1/2 in. UNF | 12.5 | 90 |
| Starter dog — petrol engines | 27.6 | 200 |
| Starter dog — diesel engines | 27.6 | 200 |
| Flywheel bolts | 8.5–9.0 | 60–65 |
| Oil filter bolts — canister to housing | 1.66 | 12 |
| Oil filter bolts — housing to cylinder block | 3.45 | 25 |
| Engine sump bolts | 1.65 | 12 |
| Manifold and exhaust system — 2¼-litre 4-cylinder petrol | ||
| Induction manifold to exhaust manifold nuts | 2.3 | 17 |
| Clutch | ||
| Clutch cover bolts | 2.48–3.04 | 18–25 |
| Gearbox | ||
| Output drive flange nut | 11.75 | 85 |
| Layshaft bolt (apply Loctite 601) | 7.00 | 50 |
| Rear axle and final drive | ||
| Hub driving flange bolts | 4.2–5.2 | 30–38 |
| Salisbury type axles — differential case bolts | 9.1–10.4 | 66–75 |
| Salisbury type axles — crownwheel bolts | 15.3–17.3 | 111–125 |
| Salisbury type axles — differential bearing cap bolts | 12.9–14.5 | 93–105 |
| Salisbury type axles — differential cover bolts | 2.8–3.5 | 20–25 |
| Rover type axles | ||
| Bevel pinion driving flange nut | 11.75 | 85 |
| Crownwheel bolts | 5.5–6.2 | 40–45 |
| Differential bearing cap bolts | 7.0–8.9 | 50–65 |
| Hub driving flange nut | 1.4–2.0 | 10–15 |
| Front axle and final drive | ||
| Hub driving flange bolts | 4.2–5.2 | 30–38 |
| Hub driving flange nut | 2.0–2.7 | 15–20 |
| Bevel pinion driving flange nut | 11.75 | 85 |
| Crown wheel bolts | 5.5–6.2 | 40–45 |
| Differential bearing cap bolts | 7.0–8.9 | 50–65 |
| Upper swivel pin bolts | 7.0–8.9 | 50–65 |
| Lower swivel pin nuts | 7.0–8.9 | 50–65 |
| Steering | ||
| Steering wheel nut | 5.4 | 40 |
| Ball joint nuts | 4.0 | 30 |
| Relay lever pinch bolts | 7.6 | 55 |
| Steering box to support bracket bolts | 7.0–8.5 | 50–60 |
| Steering box support bracket to chassis bolts | 2.0 | 15 |
| Steering box drop arm nut | 8.5–11.0 | 60–80 |
| Road wheel nuts | 10.3–11.7 | 75–85 |
| Brakes | ||
| Wheel cylinder bleed nipple | 0.5–0.8 | 4–6 |
| Master cylinder to servo nuts | 2.2–2.6 | 16–19 |
| Tipping valve retainer (dual system master cylinder) | 4.9–6.2 | 35–45 |
| Brake failure switch and pipe union | 2.2 | 16 |
| Brake failure switch unit to housing | 2.2 | 16 |
| Fluid reservoir to master cylinder bolt (single line servo) | 2.8–3.5 | 20–25 |
| Fluid reservoir to master cylinder screws (dual line servo models) | 0.3–0.4 | 2–3 |
| Servo assembly securing nuts | 1.2 | 9 |
| Suspension — all models | ||
| Leaf spring ‘U’ bolts front and rear | 8.0 | 58 |
| Shackle nuts and bolts | 8.3–9.7 | 60–70 |
| Windscreen wipers and washers | ||
| Wiper blade drive adaptor bolts | 0.34 (34 kgf·cm) | 2.5 (30 lbf·in) |
| Electrical equipment | ||
| Alternator shaft nut | 3.5–4.2 | 25–30 |
| Starter motor — petrol models | ||
| Starter through bolts | 1.0 | 8 |
Source: Land Rover Series III workshop manual, torque wrench settings, pp. 06-1–06-2 (photographed pages). Values transcribed as printed. Verify against the applicable manual and vehicle specification before use.
Engine Compression Test — 10 October 2026
| Cylinder | Compression (psi) | Compression (bar) |
|---|---|---|
| 1 | 120 | 8.27 |
| 2 | 120 | 8.27 |
| 3 | 120 | 8.27 |
| 4 | 125 | 8.62 |
| Average | 121.25 | 8.36 |
Test conditions: Engine warm, throttle fully open.
Modern Lubrication Guide – Land Rover Series III
Vehicle: 1973 Land Rover Series III 88-inch, 2¼-litre four-cylinder petrol engine (originally 8:1 compression; engine 90137598A). This practical guide uses modern lubricant specifications in place of discontinued brand names in the period handbook.
Important: These are lubricant recommendations, not a substitute for checking the actual components fitted. Check oil levels at their dipsticks or level plugs; do not fill by capacity alone. Do not substitute automatic transmission fluid or a modern Defender gearbox specification for the Series III four-speed gearbox.
Lubricants and fluids
| Diagram no. | Component | Modern recommendation | Practical notes |
|---|---|---|---|
| 20 | 2¼-litre petrol engine | SAE 20W-50 mineral or classic-engine oil, suitable for older petrol engines | Well suited to temperate Australian use. Other viscosity grades may suit colder climates; check the handbook's ambient-temperature chart. Check level with dipstick. |
| 18 | Oil-bath air cleaner (if fitted) | Same engine oil, typically SAE 20W-50 | Fill the bowl only to its marked oil-level line after cleaning. |
| 7 | Main four-speed gearbox | SAE 90 EP or 80W-90 gear oil explicitly rated API GL-4 | Choose a product clearly marked GL-4 and suitable for manual gearboxes with yellow-metal components. Do not assume a GL-5-only hypoid oil is interchangeable. |
| 8 | Transfer box | SAE 90 EP or 80W-90 API GL-4 gear oil | Check at the appropriate level plug. |
| 19, 26 | Front and rear differentials | SAE 80W-90 EP gear oil, API GL-4; a suitable GL-5 differential oil may also be used where its manufacturer confirms compatibility | Original workshop specification is GL-4 EP90. Both axles on the standard 88-inch vehicle use Rover-type differentials unless modified. |
| 4, 16 | Left and right front swivel-pin housings | SAE 90 EP / 80W-90 API GL-4 gear oil | Use oil if the housings retain their original oil-fill arrangement. Semi-fluid one-shot swivel grease is an alternative only where the conversion and component condition justify it. |
| 23 | Steering box | SAE 90 EP / 80W-90 API GL-4 gear oil | Use the appropriate fill/level point. Do not confuse with modern power-steering fluid. |
| 13 | Steering relay | SAE 90 EP / 80W-90 API GL-4 gear oil | Remove two opposite top-cover screws: one for filling and one for venting. Add slowly and allow oil to settle. Top up to the specified level rather than trying to inject a full nominal capacity. |
| 1, 2, 12, 15 | Track-rod and drag-link ball joints (where grease nipples are fitted) | NLGI 2 multipurpose lithium-based chassis grease | Some replacement sealed joints have no grease nipples and must not be drilled or forced. |
| 14, 21 | Front and rear longitudinal steering-arm ball joints (where fitted) | NLGI 2 multipurpose lithium-based grease | Grease only serviceable joints. |
| 3, 10, 17, 27 | Front and rear wheel hubs / wheel bearings | NLGI 2 high-quality wheel-bearing grease, suitable for the bearings and operating temperature | When repacking bearings, clean out old grease and avoid mixing incompatible thickener types. |
| 9, 25 | Front and rear propeller shafts | NLGI 2 multipurpose lithium-based grease | Grease universal joints and sliding splines at their nipples; wipe away excess. |
| 22, 24 | Brake and clutch hydraulic reservoirs | Fresh DOT 4 glycol-based brake fluid, provided the system contains compatible conventional seals | DOT 4 is a common modern replacement for the original DOT 3 specification. Do not mix with DOT 5 silicone fluid; if the system's current fluid is unknown, identify it before topping up. |
| 5 | Engine cooling system | Ethylene-glycol coolant with corrosion inhibitors compatible with cast-iron engines and the system's mixed metals; use the coolant maker's prescribed dilution | Prefer a conventional inhibitor chemistry compatible with the original specification. Flush thoroughly when changing coolant types; do not mix unknown formulations. |
| – | Windscreen washer bottle | Automotive windscreen-washer concentrate diluted as directed | Use a product compatible with the washer system; avoid household detergent. |
Optional equipment
If fitted, the original manual also lists a governor, hydraulic winch oil tank, rear power take-off, pulley unit and hydraulic winch gearbox. Their lubricant requirements depend on the actual equipment fitted; refer to the relevant accessory manual rather than applying the standard vehicle table indiscriminately.
Useful service notes
- Gearbox: confirm API GL-4 on the container. The original manual specifies EP90/EP80 to API GL-4 or MIL-L-2105.
- Steering relay: oil emerging immediately from the second screw hole does not necessarily mean the relay is full. Wait for trapped air to escape and the oil to settle.
- Swivels: check whether yours contain gear oil or a semi-fluid grease conversion before topping up.
- Brake and clutch: replace aged fluid periodically, and check the condition of hydraulic seals and hoses.
- Engine: viscosity choice should account for ambient temperature, oil pressure and the engine's condition; 20W-50 is a practical starting point, not a universal requirement.
References
Land Rover Series III workshop manual, lubrication chart and recommended fluids; Castrol Classic recommendations for Land Rover Series III; Series II/III 2¼-litre oil application and capacities reference.
Prepared November 2026. This is a modernised maintenance reference for the specified vehicle, not an original Land Rover publication. Check manufacturer product data before purchasing or mixing fluids.
Service lubricants, fuel, fluids and capacities
Capacities
The following capacity figures are approximate and are provided as a guide only. All oil levels must be checked using the dipstick or level plug, as applicable, with the vehicle on level ground.
| Component | Litres | Imperial unit | US unit |
|---|---|---|---|
| Engine sump oil, 4-cylinder | 6.0 | 11 pints | 13 pints |
| Engine sump oil, 6-cylinder | 6.8 | 12 pints | 14 pints |
| Extra when refilling after fitting new filter, 4-cylinder | 0.85 | 1.5 pints | 1.8 pints |
| Extra when refilling after fitting new filter, 6-cylinder | 0.5 | 1 pint | 1.2 pints |
| Air cleaner oil, 4-cylinder | 0.85 | 1.5 pints | 1.8 pints |
| Air cleaner oil, 6-cylinder | 0.5 | 1 pint | 1.2 pints |
| Main gearbox oil | 1.5 | 2.5 pints | 3 pints |
| Transfer box oil | 2.5 | 4.5 pints | 5.5 pints |
| Rear differential – Rover | 1.75 | 3 pints | 3.5 pints |
| Front differential – Rover | 1.75 | 3 pints | 3.5 pints |
| Rear differential – Salisbury 8HA | 2.5 | 4.5 pints | 5.5 pints |
| Swivel pin housing oil (each) | 0.5 | 1 pint | 1.2 pints |
| Fuel tank, 4-cylinder models except Station Wagon | 45 | 10 gallons | 12 gallons |
| Fuel tank, 6-cylinder models except Station Wagon | 50 | 11 gallons | 13 gallons |
| Fuel tank, 4-cylinder and 6-cylinder Station Wagon models | 68 | 15 gallons | 18 gallons |
| Cooling system, 4-cylinder petrol models | 8.1 | 14.25 pints | 17.1 pints |
| Cooling system, 6-cylinder petrol models | 11.2 | 20 pints | 24 pints |
| Cooling system, diesel models | 7.8 | 13.75 pints | 16.5 pints |
| Hydraulic front winch, supply tank | 20.0 | 4.5 gallons | 7.5 gallons |
| Hydraulic front winch, gearbox | 1.0 | 2 pints | 2.4 pints |
Fuel tank – service classification
| Engine | Compression ratio | Octane (manual) | Ignition timing |
|---|---|---|---|
| 2¼-litre petrol | 7.0:1 | 90 | 6° BTDC |
| 2¼-litre petrol | 7.0:1 | 83 | 3° BTDC |
| 2¼-litre petrol | 7.0:1 | 75 | TDC |
| 2¼-litre petrol | 8.0:1 | 90 | TDC |
| 2¼-litre petrol | 8.0:1 | 85 | 3° ATDC |
| 2.6-litre petrol | 7.0:1 | 83 | 2° BTDC |
| 2.6-litre petrol | 7.0:1 | 80 | TDC |
| 2.6-litre petrol | 7.0:1 | 78 | 2° ATDC |
| 2.6-litre petrol | 7.8:1 | 90 | 2° ATDC |
| 2.6-litre petrol | 7.8:1 | 85 | 6° ATDC |
| 2¼-litre diesel | – | Diesel fuel (D.E.R.V.) | |
Source: Land Rover Series III workshop manual, page 09-1. Historical octane ratings and ignition settings are reproduced as printed; do not assume the octane figures correspond directly to modern Australian RON ratings.
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