606L2, L3 Planetary Wheel Drive Gearbox Reducer

Ratios 30, 35, 43. Shorter housing, higher thermal capacity, maximum efficiency. For machines that prioritise speed and continuous duty cycle over extreme reduction.

Ratios 30, 35, 43, 68, 79. Full ratio coverage including high-reduction creep speeds. Accepts smaller-displacement, higher-speed motors for lower motor cost.

The EP-606 crosses the 10,000 Nm threshold in the planetary wheel drive gearbox range and introduces a capability that no smaller model offers: the same torque output in two different internal architectures. This matters because machine designers face a fundamental trade-off between the number of planetary stages and the motor they can use. More stages mean higher reduction per stage, which means the motor can be smaller, spin faster, and cost less — but the additional gear mesh reduces efficiency by 1-2% per stage and lengthens the housing.

The 606 L2/L3 choice lets engineers resolve this trade-off at the specification stage rather than after commitment. At ratios 30-43, both variants are available and the choice is purely about housing length, motor preference, and thermal duty. At ratios 68 and 79, only the L3 provides the necessary reduction — these high ratios are geometrically impossible in a two-stage planetary arrangement at this torque class.

Choose L2 when:

Your target ratio is 30, 35, or 43. Continuous-duty applications where thermal capacity matters (loaders cycling 8+ hours at full load). Chassis designs where the shorter housing provides critical tyre clearance. Machines that need maximum travel speed for road transit.

Choose L3 when:

Your target ratio is 68 or 79 (L2 cannot reach these). Your hydraulic system uses high-speed, small-displacement motors that benefit from the additional gear reduction. Machines operating primarily at low speeds on steep terrain where the 1% efficiency difference is less important than the traction force delivered.

Large Wheel Loaders (12-18 Tonne)

Production loaders in quarries, sand pits, and recycling yards that fill 2.5-4.0 m³ buckets at 150-200 cycles per shift. The 606L2 at ratio 35 or 43 balances stockpile penetration speed with loaded carry speed. The L2 configuration is preferred here because the continuous-duty cycle demands maximum thermal headroom. The 500-650 Nm brake option handles the 15-20% ramp grades typical of quarry haul roads.

Articulated Dump Trucks (ADTs)

ADTs in the 20-28 tonne payload class navigate steep, wet haul roads that would stop a rigid-frame truck. The 606L3 at ratio 68 or 79 provides the creep-speed traction these machines need on 20-25% loaded uphill grades. The 800 Nm brake option is essential for ADTs because the machine must hold safely on any grade it can climb while fully loaded with the engine off — a regulatory requirement in most mining jurisdictions.

Heavy Forklifts and Container Handlers

15-25 tonne capacity forklifts for steel coil handling, timber yard operations, and container depots. The 606L2 at ratio 30 or 35 provides the 15-20 km/h travel speed these machines need for productive yard transit, while the full 12,000 Nm is available for climbing loading ramps with a fully loaded mast. The slewing drive planetary gearbox handles the mast tilt and sideshift functions on the same hydraulic platform.

If both L2 and L3 produce 12,000 Nm at ratio 35, why does the L3 exist at that ratio?

At ratio 35, the L3 achieves the same output torque using a higher-speed, smaller-displacement motor — for example, a 35 cc motor at 2,450 rpm instead of a 50 cc motor at 1,715 rpm. The 35 cc motor is lighter, less expensive, and may already be in inventory for other machine systems. If the vehicle designer is standardising on a single motor displacement across multiple machine functions, the L3 configuration gives them more flexibility to do so without compromising wheel drive torque.

Can an L2 unit be field-converted to L3 by adding a third planetary stage?

No. The L2 and L3 use different housing castings with different internal cavity lengths. Adding a stage would require a different housing, different bearing arrangement, and different ring gear. The L2 and L3 are separate products that share the same output flange and wheel mounting interface but differ internally. If you need to evaluate both configurations during the development phase, Korea Ever-Power can supply one of each for back-to-back testing on the same vehicle.

What is the actual efficiency difference between the L2 and L3 at the same ratio?

Approximately 1-1.5 percentage points. The L2 at ratio 35 typically measures 94.5-95.5% on a test bench, while the L3 at the same ratio measures 93.5-94.5%. On a machine consuming 50 kW of propulsion power, this 1% difference translates to 500 watts of additional heat per wheel drive — meaningful for thermal management on continuous-duty applications but negligible for intermittent-duty machines. The L3 efficiency is still vastly superior to any worm gear wheel drive alternative.

What determines whether a planetary wheel drive needs a 2-stage or 3-stage configuration?

Physics. A single planetary stage can produce a ratio of approximately 3:1 to 10:1, depending on the sun-to-ring gear tooth count combination. Two stages in series can therefore produce ratios from roughly 9:1 to 100:1, and three stages from 27:1 to 1,000:1. The 606L2 ratios (30-43) fall within the practical two-stage range. The 606L3 ratios 68 and 79 require the multiplicative effect of three stages because no two-stage combination can reach those values at this torque class while maintaining acceptable gear tooth stress levels.

How does the 800 Nm brake compare to disc brakes at the wheel rim?

The 800 Nm brake on the 606 acts at the gearbox input shaft and is multiplied through the gear ratio to the wheel. At ratio 43, the effective holding torque at the wheel is 34,400 Nm — equivalent to a friction disc brake with a 1,200 mm diameter rotor. No wheel-rim-mounted disc brake of practical size can match this. The trade-off is that the gearbox input brake cannot function as a dynamic service brake during driving — it is designed only for static holding. Dynamic braking must be provided by the hydrostatic circuit. For machines that require a combination of hydrostatic dynamic braking and mechanical static holding, the 606 with integral input brake provides the most compact and weight-efficient solution.

What maintenance interval applies to the 606L2/L3 in quarry applications?

Oil change every 1,500 hours (reduced from the standard 2,000 hours due to the abrasive dust environment). First change at 250 hours. Use SAE 80W-90 GL-5 EP oil. Inspect the output shaft seal and wheel mounting studs at every oil change. Check brake release pressure and verify that the brake engages fully when the release line is depressurised. The brake disc is a wear component — inspect disc thickness at 5,000-hour intervals and replace when it reaches the minimum thickness marked on the disc. In quarry conditions, expect a brake disc life of 8,000-15,000 hours depending on the frequency of slope-parking events.

Six 606L2 units at ratio 43 on our 15-tonne production loaders. These machines run 10-hour shifts, 6 days a week, filling haul trucks from a granite stockpile. After 14 months and roughly 3,600 hours per unit, no bearing issues, no seal leaks, and the brake disc inspection at 3,000 hours showed minimal wear. The oil analysis trending is clean. The L2 was the right call for this application — continuous duty at 43:1 needs the thermal headroom that the shorter two-stage housing provides.

We prototyped both the 606L2 at ratio 43 and the 606L3 at ratio 68 on our 25-tonne ADT platform during the development phase. Ever-Power supplied one of each for back-to-back testing on the same vehicle. The L3 at 68 won because our haul roads in the target market (West African gold mining) average 22% grade and the extra reduction meant we could use a smaller pump without sacrificing loaded hill-climb speed. The L2 at 43 went into our flat-terrain quarry variant. Same vehicle, two spec sheets, one wheel drive family.

Steel coil handling forklift, 20-tonne capacity, 606L2 ratio 30. The drive handles the 16% ramp into our warehouse with a loaded coil without any hesitation. The 500 Nm brake holds on the ramp with engine off. The 4-star is because our chassis design left very tight clearance between the 606 housing and the inner fender, and the L2 barely fits — the L3 would not have cleared. It would help if the product data sheet included a clear dimensional envelope drawing so we could have verified this before the first prototype. The drive itself is performing well.