{"id":893,"date":"2026-06-18T01:48:19","date_gmt":"2026-06-18T01:48:19","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?post_type=product&p=893"},"modified":"2026-06-18T01:48:19","modified_gmt":"2026-06-18T01:48:19","slug":"603l2b-planetary-wheel-drive-gearbox","status":"publish","type":"product","link":"https:\/\/planetary-gearboxes.com\/ko\/product\/603l2b-planetary-wheel-drive-gearbox\/","title":{"rendered":"603L2B Planetary Wheel Drive Gearbox Reducer \u2014 2-Stage"},"content":{"rendered":"
\n

<\/p>\n

\n
\n
\n
EP-603 Series \u00b7 Heavy-Duty Variant<\/div>\n

603L2B Planetary Wheel Drive<\/h2>\n

The reinforced variant \u2014 when standard bearings are not enough.<\/p>\n

The EP-603L2B exists because not every 4,000 Nm application is created equal. A telehandler on a paved yard and a forestry forwarder on a 40-degree side-slope both need the same output torque, but the forwarder subjects the wheel drive planetary gearbox<\/a> to radial forces that would overwhelm the standard-duty bearings of the 603L2A within a few thousand hours. The L2B adds 10 kg of housing mass and steps up to an oversized bearing set specifically engineered for these extreme side-load conditions.<\/p>\n

Beyond the bearing upgrade, the L2B extends the cold-start capability to -25 deg C (versus -20 deg C for the L2A) and provides additional motor adapter mounting provisions for non-standard hydraulic motor flanges \u2014 two details that matter disproportionately in mining and forestry environments where temperatures drop hard and motor interchangeability across a mixed fleet reduces inventory cost.<\/p>\n<\/div>\n

\n

\"603L2B<\/p>\n

\n
\n
4,000<\/div>\n
Nm Output<\/div>\n<\/div>\n
\n
95 kg<\/div>\n
Reinforced<\/div>\n<\/div>\n
\n
-25\u00b0C<\/div>\n
Cold Start<\/div>\n<\/div>\n
\n
4<\/div>\n
\ube44\uc728<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

603L2B Heavy-Duty Wheel Drive \u2014 Technical Parameters<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Output torque (rated max)<\/td>\n4,000 Nm<\/td>\n<\/tr>\n
\uae30\uc5b4\ube44<\/td>\n19 : 1 \u00a0|\u00a0 23 : 1 \u00a0|\u00a0 32 : 1 \u00a0|\u00a0 40 : 1<\/td>\n<\/tr>\n
Planetary stages<\/td>\n2<\/td>\n<\/tr>\n
Maximum input speed<\/td>\n3,000 rpm<\/td>\n<\/tr>\n
Mechanical efficiency<\/td>\n\u2265 95%<\/td>\n<\/tr>\n
\uc8fc\ucc28 \ube0c\ub808\uc774\ud06c<\/td>\n210 Nm input-side, spring-applied, hydraulic release<\/td>\n<\/tr>\n
Emergency towing<\/td>\nManual declutch (free-wheel disconnect)<\/td>\n<\/tr>\n
Wheel mounting<\/td>\nRotating flange, SAE\/ISO bolt circle, heavy-duty configuration<\/td>\n<\/tr>\n
Dry weight<\/td>\nApprox. 95 kg (reinforced housing)<\/td>\n<\/tr>\n
\ub9e4\ub044\ub7fd\uac8c \ud558\uae30<\/td>\nOil bath splash, API GL-5 EP gear oil<\/td>\n<\/tr>\n
\uc791\ub3d9 \uc628\ub3c4<\/td>\n-25 to +85 deg C (Viton seals available)<\/td>\n<\/tr>\n
Gear material<\/td>\nCarburised alloy steel, CNC ground, HRC 58-62<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

<\/p>\n

\n

603L2A or 603L2B \u2014 How to Decide Between Two Wheel Drive Gearbox Variants<\/h2>\n

Both variants deliver identical torque, ratios, and efficiency. The decision comes down to what the application does to the wheel hub bearings once the gearbox is bolted to the machine.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n
\ud45c\uc900<\/th>\n603L2A<\/th>\n603L2B<\/th>\n<\/tr>\n<\/thead>\n
Dry weight<\/td>\n85 kg<\/td>\n95 kg<\/td>\n<\/tr>\n
Radial bearing capacity<\/td>\n\uae30\uc900<\/td>\nOversized (heavy-duty)<\/td>\n<\/tr>\n
Cold-start limit<\/td>\n-20 deg C<\/td>\n-25 deg C<\/td>\n<\/tr>\n
Motor adapter options<\/td>\nStandard SAE<\/td>\nExtended, multi-pattern<\/td>\n<\/tr>\n
Tyre diameter range<\/td>\nUp to 700 mm<\/td>\nUp to 900 mm+<\/td>\n<\/tr>\n
Typical terrain<\/td>\nPaved, firm soil, flat<\/td>\nRocks, ruts, steep sideslope<\/td>\n<\/tr>\n
\ube44\uc6a9<\/td>\n\ub0ae\ucd94\ub2e4<\/td>\n\ub354 \ub192\uc740<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Decision rule: <\/span>
\nIf the machine uses tyres larger than 700 mm overall diameter, operates on terrain with cross-slopes exceeding 20%, or requires cold starts below -20 deg C, specify the L2B. For all other 4,000 Nm applications, the L2A delivers the same performance at lower weight and cost.<\/span><\/div>\n<\/section>\n

<\/p>\n

\n

What Destroys Wheel Drive Bearings \u2014 and How the L2B Prevents It<\/h2>\n

The output torque specification of a planetary wheel drive gearbox tells you how much rotational force the gears can transmit. It says nothing about the radial forces that act perpendicular to the shaft axis \u2014 forces generated by tyre side-loads during cornering, terrain camber, impact with rocks and stumps, and the static weight reaction from the vehicle mass. These are the forces that destroy output bearings.<\/p>\n

\"603L2B<\/p>\n

\n
\n

Cornering Side-Load<\/strong><\/p>\n

When a vehicle corners, the centripetal force transfers through the tyre contact patch as a lateral force on the wheel hub. Larger tyres amplify this force because the moment arm (tyre width plus offset) increases. A 900 mm off-road tyre on a 6-tonne machine cornering at 15 km\/h generates 8,000-12,000 N of radial side-load on each outer wheel drive bearing \u2014 forces that act in addition to the vehicle weight reaction.<\/p>\n<\/div>\n

\n

Cross-Slope Operation<\/strong><\/p>\n

Forestry forwarders and mining haul vehicles routinely traverse 20-40 degree cross-slopes. At 30 degrees, half the vehicle weight transfers laterally through the downhill wheel bearings as a sustained radial load. On a 7-tonne machine, each downhill wheel drive absorbs approximately 17,000 N of continuous radial force. Standard bearings designed for flat-terrain operation will pit and spall within 3,000-5,000 hours under these conditions.<\/p>\n<\/div>\n

\n

Impact Loading<\/strong><\/p>\n

Striking a rock, stump, or kerb at speed generates a radial shock load of 3-5 times the static wheel load. On rough terrain where this occurs multiple times per hour, the cumulative damage to undersized bearings is rapid. The L2B oversized tapered roller bearings have approximately 40% higher dynamic load rating than the L2A set, extending the L10 bearing life proportionally under these repeated impact conditions.<\/p>\n<\/div>\n

\n

Large-Diameter Tyre Effect<\/strong><\/p>\n

Larger tyres increase the moment arm between the tyre contact patch and the gearbox output bearing. A 900 mm tyre creates approximately 30% more bending moment on the output bearing than a 700 mm tyre under the same cornering or side-slope conditions. The L2B housing geometry accommodates this increased moment by moving the output bearing further apart axially, reducing the bearing contact stress for the same external load.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

Where the Heavy-Duty Planetary Wheel Drive Earns Its Extra Weight<\/h2>\n

\"Heavy-duty<\/p>\n

\n
\n
\n

Forestry Forwarders and Skidders<\/h3>\n

Forestry machines operate on steep side-slopes, over root mats, and through deep ruts where the wheel hub is constantly subjected to multi-directional radial loading. The 603L2B at ratio 32 or 40 provides the low-speed traction these machines need to haul 8-12 tonne log bundles uphill, while the oversized bearings absorb the side-loads from driving over root balls and across drainage ditches at full load.<\/p>\n<\/div>\n

\n

Underground Mining Utility Vehicles<\/h3>\n

Mine service vehicles, personnel carriers, and explosives trucks operate on uneven drift floors with standing water, rock debris, and tight turns around pillars. The -25 deg C cold-start rating covers deep-mine environments where ventilation air chills the equipment overnight. The sealed housing resists the abrasive rock dust and shotcrete overspray that would penetrate chain or gear drives within weeks.<\/p>\n<\/div>\n

\n

Rough-Terrain Forklifts with Oversize Tyres<\/h3>\n

Military logistics forklifts, pipeline construction material handlers, and plantation agricultural equipment<\/a> that use 800-900 mm diameter off-road tyres for ground clearance and flotation. The larger tyre-to-hub moment arm makes the L2B oversized bearings a structural necessity rather than an optional upgrade. At ratio 19, these machines achieve 20+ km\/h travel speed for road transit between remote work sites.<\/p>\n<\/div>\n<\/div>\n

\n
\n

L2B Target Environments<\/h3>\n