# Mercedes-Benz L 337

The Mercedes-Benz L 337 is a lorry made by Daimler-Benz, sold under the Mercedes-Benz brand. Introduced in March 1959, it was already discontinued in 1961, and replaced with the L 338. The L 337 is the first generation of Mercedes-Benz' heavy-duty "short-bonnet lorries", and has, in its default configuration, the "long" short bonnet, which is 300 mm longer than the typical Mercedes-Benz medium duty short-bonnet lorry's bonnet. Mercedes-Benz also offered the L 337 as a forward-control lorry, called the LP 337.
The L 337 was designed to comply with "Seebohm's legislation", which limited the maximum permissible total mass of lorries registered in West-Germany to 12,000 kg (plus another 12,000 kg of trailer mass). However, the L 337 was rendered obsolete by rescindment of this legislation in 1960.

## Models

* L 337: Base model, offered either as a rolling chassis or with a flatbed
* LK 337: Tipper lorry
* LP 337: Forward control lorry
* LS 337: Tractor
* LPS 337: Forward control tractor

## Description

The L 337 is a two-axle lorry with a total permissible mass of 12,000 kg and rear-wheel drive. It has a ladder frame with U-profile longitudinal sections. At launch, Mercedes-Benz offered three different wheelbase options, (3700 mm, 4200 mm, and 4400 mm); in 1960, a 5000 mm option was added. The cab is either the long version of the short-bonnet lorry cab (L, LK models), or the short version of the forward-control cab (LP models). From 1960, Mercedes-Benz offered a long variant of the forward-control cab (LP models).
Both front and rear axles are beam axles. The front axle is a stub (dead) axle, the rear axle is a hypoid drive (live) axle. Usually, such axles do not have additional reduction gearboxes if used in large on-road lorries. However, the L 337's hypoid axle was fitted with an additional, pneumatically-shifted two-speed planetary gearbox, giving the lorry 5 × 2 = 10 forward gears. This design allowed Daimler-Benz to install their modular Daimler-Benz G 32 synchromesh five speed gearbox, which otherwise would not have had proper gear spreading. The clutch used to transmit the torque from the engine to the gearbox is a dry Fichtel & Sachs GF 50 KR BH single-disc clutch. The engine used in the L 337 is the naturally aspirated, straight-six OM 326IV Diesel engine. It is precombustion chamber injected, water-cooled, and rated 190 hp (SAE gross) / 172 PS; 127 kW (DIN 70020).

## Technical specifications

Technical specifications (April 1959) :
| | L 337 | LK 337 | LP 337 |
| Dimensions and weights ||||
| Wheelbase (mm) | 4400 | 4200 | 3700/4200 |
| Length (mm) | 7650 | 7050 | 6960/7920 |
| Width (mm) | 2400 | 2430 | 2400 |
| Height (mm) | 2470 | 2490 | 2560 |
| Front track width (mm) | 1906 | 1906 | 1906 |
| Rear track width (mm) | 1788 | 1788 | 1788 |
| Ground clearance (mm) | 252 | 252 | 252 |
| Mass (kg) | 4770 | 5370 | 4740/4950 |
| Payload (kg) | 7230 | 6630 | 7260/7050 |
| Max. permissible mass (kg) | 12,000 | 12,000 | 12,000 |
| Powertrain ||||
| Clutch | Dry single-disc clutch Fichtel & Sachs/GF 50 KR/BH | Dry single-disc clutch Fichtel & Sachs/GF 50 KR/BH | Dry single-disc clutch Fichtel & Sachs/GF 50 KR/BH |
| Gearbox | Five-speed synchromesh gearbox Daimler-Benz G 32 | Five-speed synchromesh gearbox Daimler-Benz G 32 | Five-speed synchromesh gearbox Daimler-Benz G 32 |
| Driven axle | Rear axle | Rear axle | Rear axle |
| Gear ratios | 1st: 6.106:1 2nd: 3.24:1 3rd: 2.19:1 4th: 1.467:1 5th: 1:1 R: 5.64:1 | 1st: 6.106:1 2nd: 3.24:1 3rd: 2.19:1 4th: 1.467:1 5th: 1:1 R: 5.64:1 | 1st: 6.106:1 2nd: 3.24:1 3rd: 2.19:1 4th: 1.467:1 5th: 1:1 R: 5.64:1 |
| Top speed (km/h) | 72.5 | 72.5 | 83.5 |
| Brake drum area (cm$^2$) | 2830 | 2830 | 2830 |
| Engine ||||
| Type designation | Mercedes-Benz OM 326IV | Mercedes-Benz OM 326IV | Mercedes-Benz OM 326IV |
| Type | Naturally aspirated straight-six Diesel | Naturally aspirated straight-six Diesel | Naturally aspirated straight-six Diesel |
| Fuel system | Precombustion chamber injection; inline injection pump | Precombustion chamber injection; inline injection pump | Precombustion chamber injection; inline injection pump |
| Valvetrain | Four overhead valves | Four overhead valves | Four overhead valves |
| Cooling system | Water | Water | Water |
| Bore × Stroke | 128 × 140 mm | 128 × 140 mm | 128 × 140 mm |
| Displacement | 10,809 cm$^3$ | 10,809 cm$^3$ | 10,809 cm$^3$ |
| Power (DIN 70020) | 172 PS (127 kW) at 2200 rpm | 172 PS (127 kW) at 2200 rpm | 172 PS (127 kW) at 2200 rpm |
| Power (SAE gross) | 190 HP at 2200 rpm | 190 HP at 2200 rpm | 190 HP at 2200 rpm |
| Max. Torque (DIN 70020) | 58 kp⋅m (569 N⋅m) at 1300 rpm | 58 kp⋅m (569 N⋅m) at 1300 rpm | 58 kp⋅m (569 N⋅m) at 1300 rpm |
| Average piston speed | 10.3 m/s | 10.3 m/s | 10.3 m/s |
| Compression ε | 20.5 | 20.5 | 20.5 |
| Mean effective pressure | 6.75 kp·cm$^{−2}$ (662 kPa) | 6.75 kp·cm$^{−2}$ (662 kPa) | 6.75 kp·cm$^{−2}$ (662 kPa) |
| Injection pressure | 135 atü (13.2 MPa) | 135 atü (13.2 MPa) | 135 atü (13.2 MPa) |
| Firing order | 1-5-3-6-2-4 | 1-5-3-6-2-4 | 1-5-3-6-2-4 |
| Inlet opens | 31° before TDC | 31° before TDC | 31° before TDC |
| Inlet closes | 67° after BDC | 67° after BDC | 67° after BDC |
| Outlet opens | 69° before BDC | 69° before BDC | 69° before BDC |
| Outlet closes | 33° after TDC | 33° after TDC | 33° after TDC |
| Engine mass | 805 kg | 805 kg | 805 kg |
| Rated fuel consumption (DIN 70030, in l/100 km) | 18.1 | – |
| Fluid capacities ||||
| Fuel tank (l) | 100 | 100 | 100 |
| Oil pan (l) | 9–12 | 9–12 | 9–12 |
| Cooler (l) | 40 | 40 | 40 |
| Gearbox (l) | 3.7 | 3.7 | 3.7 |
| Electrical system ||||
| Starter motor | 24-V sliding armature starter Bosch BPD 6/24 AR 169 | 24-V sliding armature starter Bosch BPD 6/24 AR 169 | 24-V sliding armature starter Bosch BPD 6/24 AR 169 |
| Generator | Bosch LJ/GK 300/12-1400 AR 18 (12 V, 300 W) Driven starting from crankshaft speeds of 660 rpm | Bosch LJ/GK 300/12-1400 AR 18 (12 V, 300 W) Driven starting from crankshaft speeds of 660 rpm | Bosch LJ/GK 300/12-1400 AR 18 (12 V, 300 W) Driven starting from crankshaft speeds of 660 rpm |
| Batteries | 2 × Lead-acid, 12 V, 105 Ah | 2 × Lead-acid, 12 V, 105 Ah | 2 × Lead-acid, 12 V, 105 Ah |
| Sources | | | |