Caterpillar 322B LN
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 322B LN is a 23-25 tonne class hydraulic crawler excavator built from 1998 to 2002 as part of Caterpillar's B-series medium excavator line. It runs the Cat 3116TA turbocharged, air-to-air aftercooled inline-six diesel, rated at roughly 120 kW (161 hp) gross and 114 kW (153 hp) net at 1950 rpm, feeding a mechanical, ECM-free unit-injection fuel system. Operating weight runs about 23.8 to 24.8 t (roughly 52,500-54,700 lb) depending on boom, stick, and counterweight configuration and which factory spec sheet is used. The "LN" suffix marks the long-and-narrow-gauge undercarriage variant of the standard 322B: it keeps the long track base for stability and flotation while narrowing the gauge for confined or soft-ground sites. Caterpillar offered it alongside the standard-gauge 322B and the wide 322B L, each with a choice of boom and stick lengths.
The 322B LN sits between the original 322 LN (1995-1998) and the 322C LN (about 2002-2005) in Caterpillar's medium-excavator lineage. Where the C-series successor moved to the Cat 3126B engine with electronic unit injection and higher gross output, the 322B LN keeps a simpler mechanically governed fuel system with no engine ECM, which owners and independent shops still value for straightforward field diagnostics. Undercarriage, linkage, and structural components carry over closely across the 322, 322B, 322B L, and 322C L family, which keeps the used-parts network deep even though the model has been out of production for two decades. That mix of parts commonality, mechanical simplicity, and low acquisition cost keeps the 322B LN working in swamp, pipeline, and confined-site jobs where its narrow gauge and long track base are still an advantage.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar 322B LN specifications
Engine
| Engine model | Cat 3116TA, inline-6, turbocharged and aftercooled |
| Gross power | 120 kW (161 hp) at 1950 rpm |
| Net power | 114 kW (153 hp) at 1950 rpm |
| Displacement | 6.6 L (403 cu in) |
| Cylinders | 6, inline |
| Bore x stroke | 107 mm x 127 mm (4.2 in x 5.0 in) |
| Emissions certification | Not documented for this production/serial range in available spec sheets. Verify emissions certification with your dealer. |
Weights
| Operating weight (322B LN, long-undercarriage/narrow-gauge config) | 23.8-24.8 t (52,490-54,680 lb), varies by configuration/series |
| Operating weight (322B L, standard-gauge sibling, for reference only) | 22.76 t (50,177 lb) - lighter standard-gauge chassis, not the LN configuration |
| Ground pressure | Not published in available spec sheets for this configuration. Depends on shoe width fitted; verify with your dealer. |
| Shipping/transport weight | No separate shipping weight documented; operating weight figure above applies |
Dimensions
| Transport length | 10.35 m (33.96 ft), standard reach boom/stick |
| Transport width (over tracks) | 2.99 m (9.81 ft) |
| Track gauge | 2.59 m (8.5 ft), narrow-gauge undercarriage |
| Transport height | 3.21 m (10.54 ft), standard reach boom/stick; cab top height about 3.14 m (10.31 ft) |
| Tail swing radius | 3.05 m (10.01 ft) |
| Track shoe width | 600 mm (23.63 in), standard shoe |
| Ground clearance | 0.48 m (1.58 ft) |
| Undercarriage length (track on ground) | 3.80 m (12.47 ft) |
| Removal counterweight clearance | 1.13 m (3.71 ft) |
Performance
| Max dig depth | 6.69 m (21.95 ft) with standard boom/stick; as low as 5.42 m (17.79 ft) with a shorter boom/stick option |
| Max reach at ground level | 10.00 m (32.81 ft) with standard boom/stick; as low as 8.65 m (28.38 ft) with a shorter boom/stick option |
| Max dump/loading height | 6.75 m (22.15 ft) |
| Max cutting height | 9.62 m (31.57 ft) |
| Max travel speed | 5.5 km/h (3.42 mph) |
| Swing speed | Not documented in available spec sheets for this model |
| Gradeability | Not documented in available spec sheets for this model |
| Max drawbar pull | 194 kN (43,650 lbf) |
| Swing torque | 70.3 kN.m (51,850 lbf.ft), shared swing system across the 322B/322B L/322B LN family |
Forces
| Bucket digging force | Not published in available spec sheets for this model/vintage. Ask your dealer for bucket-specific breakout figures. |
| Stick (arm) digging force | Not published in available spec sheets for this model/vintage. Would vary between standard and long stick options where offered. |
Service capacities (summary)
| Fuel tank | 340 L (89.9 gal) |
| Hydraulic system | 265 L (70.1 gal) |
| Engine oil | 21.5 L (5.7 gal) |
| Cooling system | 31.5 L (8.4 gal) |
| Swing drive | 8 L (2.2 gal) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
322B LN fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | 21.6 L (5.7 US gal) | Cat DEO (Diesel Engine Oil). SAE 15W-40 for normal ambient range; SAE 10W-30 for cold-weather starts below roughly -18°C (0°F), per Cat's standard multigrade oil guidance for the 3116TA diesel fitted to this machine. |
| Cooling system | 31.8 L operating fill (8.4 US gal); about 31.4 L (8.3 US gal) service refill | Cat DEAC (Diesel Engine Antifreeze/Coolant), full-strength or premix per Cat's standard concentration table. Cat ELC (Extended Life Coolant) is listed as an alternative on later printings. |
| Fuel tank | 340.3 L operating (89.9 US gal); about 340.7 L (90.0 US gal) service refill | No. 2-D diesel fuel meeting Cat's fuel specification. Use a winterized blend below freezing per the OMM cold-weather guidance. |
| Hydraulic system total (incl. tank) | 265.3 L operating (70.1 US gal); about 265.0 L (70.0 US gal) service refill, tank included | Cat TDTO/HYDO-class hydraulic oil, viscosity grade selected by ambient temperature (roughly SAE 10W in cold climates up to SAE 30W in hot climates). Hydraulic tank-only capacity is not separately published for this model; tank refill is a portion of the total system figure above — fill to the sight-gauge mark, not by a fixed tank-only number. |
| Final drive (each) | 9.8 L per side (2.6 US gal) | Cat TDTO (Transmission/Drive Train Oil), viscosity grade by ambient temperature (roughly SAE 30 in cold climates up to SAE 50 in hot climates). |
| Swing drive | 8.3 L operating (2.2 US gal); about 9.8 L (2.6 US gal) service refill | Cat TDTO (Transmission/Drive Train Oil), same viscosity-by-temperature selection as the final drives. |
| Grease (spec only) | No fixed fill volume — applied per lubrication point at scheduled greasing intervals | Cat Multipurpose grease (NLGI 2 lithium-complex) for general pins and bushings; Cat Extreme Application grease where the OMM calls out high-load or high-temperature points. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 322B LN maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 6,000 h |
|
Servicing the 322B LN beyond the schedule
Predictive Maintenance & Fluid Analysis
The 3116TA has no engine ECM, so there are no fault codes to lean on. Track condition through scheduled S.O.S sampling of engine oil, hydraulic oil, swing drive oil, and final drive oil, and trend wear metals rather than wait for a leak or a noise. Watch turbocharger boost and exhaust smoke for early injector wear on this mechanically governed fuel system. Check swing bearing grease purge and mounting-bolt torque regularly — on the long/narrow undercarriage, a loose bearing shows up as steering wander before it shows up as noise.
Corrective & Common Repairs
Expect mechanical unit-injector wear on the 3116TA first — it shows as hard cold starts, rough idle, and white or black smoke, and it's a bench-test-and-rebuild job, not a swap. Turbocharger shaft play and boost leaks follow next. On the long/narrow undercarriage, track pins, bushings, and idlers wear faster than the standard-gauge 322B because tighter turning radius on confined sites loads them harder. Hydraulic cylinder rod seals at the boom, stick, and bucket pins weep with age, and wiring harness connectors corrode — inspect grounds before chasing electrical gremlins.
Overhaul & Rebuild Points
At this machine's age, plan overhauls around the swing drive and final drive gearboxes, the main hydraulic pump, and the swing motor — all wear items on a machine that's likely working its second or third owner. The 3116TA's mechanical injection pump and unit injectors are a factory-exchange or specialist-rebuild job, not a shade-tree fix. Swing bearing replacement is a major undertaking once backlash or grease purge tests fail. Budget for a full undercarriage rebuild — chains, rollers, idlers, sprockets — since the long/narrow gauge wears unevenly versus standard 322B.
Seasonal & Environment Servicing
Cold starts on the 3116TA rely on ether or glow-plug aids and correct coolant concentration — check the antifreeze mix and battery condition before winter, since this machine predates cold-start automation on later Cat engines. The long/narrow undercarriage is built for soft, wet, or confined ground, so clear packed mud from the track frame, rollers, and idlers after swamp or wetland work to stop binding and accelerated pin wear. In hot, dusty conditions, clean the radiator and hydraulic oil cooler fins more often than the standard 250-hour interval calls for.
322B LN fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| 2302 | Governor actuator feedback signal is unstable or deviates from the expected value. | Worn or misadjusted governor actuator linkage, a faulty feedback element inside the actuator, or a loose/corroded connector on the actuator harness. | Check the actuator wiring and connector for corrosion or looseness, confirm the linkage moves freely through its full travel, then run the engine speed control calibration in dealer service mode; replace the actuator if the signal still will not settle. |
| A201 | Monitor is not communicating normally with the machine controller. | Break or corrosion in the two-wire data link between the cab monitor panel and the pump/engine speed controller, a blown fuse feeding either unit, or a failed monitor. | Inspect the monitor-to-controller data harness and connectors, check fuses feeding the monitor and controller, and confirm battery voltage reaches both units before condemning either component. |
| A202 | Monitor takes too long to respond to a signal from the controller. | Marginal data-link connection (partial short or high resistance in the wiring) or a monitor beginning to fail. | Clean and reseat the data-link connectors, check for chafed wiring near routing clips, and retest; replace the monitor if the delayed response continues. |
| 1302 | Engine oil pressure has dropped below the normal operating range. | Low engine oil level, a clogged oil filter, a worn oil pump, or a failing oil pressure sensor. | Shut the machine down and check oil level and filter condition first; if both are fine, check the oil pressure sensor and its wiring before suspecting the oil pump. |
| 1303 | Engine coolant temperature has risen above the normal operating range. | Low coolant level, a clogged radiator core or blocked fan guard, a slipping or failed fan drive, or a stuck thermostat. | Check coolant level and clean debris from the radiator core, confirm the cooling fan turns at full speed, then check the coolant temperature sensor if the cooling system checks out mechanically. |
| 1304 | Hydraulic oil temperature has risen above the normal operating range. | Low hydraulic oil level, a dirty hydraulic oil cooler core, a failing cooling fan, or sustained high-load operation in hot ambient conditions. | Check hydraulic oil level and cooler core cleanliness, confirm the cooling fan runs at full speed, and ease off sustained high-load work until the cause is found. |
| 1305 | An inlet filter element is restricted or blocked. | A dirty hydraulic return/suction filter element, or a filter bypass condition from an overdue service interval. | Inspect and replace the affected filter element, check the bypass indicator, and confirm the correct element was installed at the last service. |
| 2201 | Battery or charging system voltage is outside the normal range. | A weak or failing battery, a bad ground connection, a slipping alternator belt, or a failing alternator/regulator. | Load-test the battery, check ground straps and battery terminals for corrosion, and test alternator belt tension and charging output. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
322B LN attachments & work tools
Buckets
General-purpose buckets pin onto the 322B LN's stick and link with an 80 mm (3.15 in) pin, the same B-Link bucket geometry shared across the Cat 320-325 B/C excavator class. Heaped capacity typically runs about 0.76-1.53 m3 (1.0-2.0 cu yd) depending on boom/stick reach configuration, with roughly 1.0-1.1 m3 (1.4 cu yd) commonly used as a standard trenching bucket on this long-reach LN setup. Heavy-duty and rock/severe-duty buckets of the same width hold less material than a general-duty bucket because of thicker wear plate and a reinforced tooth/GET package. Typical widths for this size class run about 600 to 1,500 mm (24-60 in): narrower for trenching, wider for grading and cleanup.
Hydraulic hammers
The 322B LN sits in the mid-frame breaker bracket used for roughly 18-27 tonne carriers. In current Cat hammer nomenclature that lands around the H115-H120 class, with a working weight in the neighborhood of 1,000-1,500 kg (2,200-3,300 lb). Expect auxiliary flow demand around 120-180 L/min (32-48 gpm) and operating pressure roughly 160-180 kg/cm2 (2,270-2,560 psi); exact figures vary by hammer brand and series, so match the specific breaker's own data plate to this machine's aux circuit before ordering.
Quick couplers
Hydraulic pin-grabber quick couplers built for the Cat 320/322/325/330 excavator class fit the 322B LN's 80 mm bucket pin (some coupler designs step up to a 90 mm pin on the link side). Manual wedge-style mechanical couplers sized to the same pin spacing also fit. Either style bolts into the existing B-Link bucket linkage without changing the stick pin.
Thumbs/grapples
Pin-on hydraulic thumbs and rotating grapples built for the Cat 318-325 size range mount off the same stick/bucket pin and link as the factory bucket. Cat's own literature for this excavator lists hammers, shears, rotators and grapples among the supported work-tool classes. A grapple rotator or thumb kit that needs continuous rotation runs through a field-installed combine/rotate auxiliary circuit rather than a plain single-acting aux line.
Rippers
A single-shank, stick-mounted ripper sized for the 20-25 tonne excavator class pins into the same bucket linkage as a general-purpose bucket, swapped in for it. It scarifies hard-packed, frozen, or lightly cemented ground and breaks up rock or asphalt ahead of bucket work rather than doing continuous production ripping. No 322B LN-specific ripper spec sheet turned up in research; size it off the standard 20-25 ton class and verify fitment with the attachment maker.
Hydraulic-kit notes
The 322B LN's factory attachment plumbing is a standard-pressure auxiliary circuit (auxiliary control group feeding auxiliary hydraulic lines out to the stick), with a rotator/combine-function circuit available as a field-installed kit for grapples and rotating thumbs. No factory high-flow (XPS-type) circuit is documented for this B-series LN configuration; that capability arrived later in Cat's excavator lineup. For flow-hungry tools like large hammers or mulching heads, have a dealer confirm installed pump and valve capacity against the tool's requirement before ordering.
All 322B LN assemblies by section
Every catalogued assembly group for the Caterpillar 322B LN. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Electrical And Starting System
Cp-1384670 Mounting Gp-Control
| 13***70 | Control & Mtg Group-Auxiliary Flow | 1 |
Cp-1384653 Control Gp-Foot
| 13***53 | Control Group-Foot | 1 |
Cp-1534157 Harness As
| 15***57 | Harness As | 1 |
Cp-1415403 Harness As
| 14***03 | Harness As | 1 |
Cp-1534110 Harness As
| 15***10 | Harness As | 1 |
Cp-1534159 Harness As.
| 15***59 | Harness As. | 1 |
Cp-1534156 Harness As.
| 15***56 | Harness As. | 1 |
Cp-1534109 Harness As.
| 15***09 | Harness As. | 1 |
Cp-1361208 Harness As.
| 13***08 | Harness As. | 1 |
Cp-1376946 Harness As.
| 13***46 | Harness As. | 1 |
Cp-1330958 Harness As.
| 13***58 | Harness As. | 1 |
Cp-1415418 Panel Gp-Relay
| 14***18 | Panel Group-Relay | 1 |
Cp-1534111 Wiring Gp-Auxiliary Control
| 15***11 | Wiring Group-Auxiliary Control | 1 |
Cp-1284946 Wiring Gp-Auxiliary Control
| 12***46 | Wiring Group-Auxiliary Control | 1 |
Cp-1415401 Wiring Gp-Auxiliary Control
| 14***01 | Wiring Group-Auxiliary Control | 1 |
| 14***03 | Harness As | 1 |
| 14***18 | Panel Group-Relay | 1 |
Cp-1534132 Wiring Gp-Auxiliary Control
| 15***32 | Wiring Group-Auxiliary Control | 1 |
Hydraulic System
Cp-1384665 Control Ar-Auxiliary
| 12***60 | Lines Group-Pilot | 1 |
| 12***66 | Film Group; Film Gp-Combined Function | 1 |
| 13***65 | Control Ar-Auxiliary | 1 |
Cp-1384652 Control Gp-Joystick
| 13***52 | Control Group-Joystick | 1 |
Cp-1297995 Drive Gp-Pump
| 12***95 | Drive Group-Pump | 1 |
Cp-1466545 Hose As.
| 14***45 | Hose As. | 1 |
Cp-1384666 Hydraulic Ar
| 13***66 | Hydraulic Ar | 1 |
Cp-1466516 Lines Gp-Attachment
| 14***16 | Lines Group | 1 |
Cp-1384632 Lines Gp-Auxiliary Hydraulic
| 13***32 | Lines Group-Auxiliary Hydraulic | 1 |
Cp-1384466 Lines Gp-Auxiliary Hydraulic
| 13***66 | Lines Group-Auxiliary Hydraulic | 1 |
Cp-1446343 Lines Gp-Auxiliary Hydraulic
| 14***43 | Lines Group-Auxiliary Hydraulic | 1 |
Cp-1411132 Lines Gp-Auxiliary Hydraulics
| 14***32 | Lines Group-Auxiliary Hydraulics | 1 |
Cp-1434538 Lines Gp-Drain
| 14***38 | Lines Group-Drain | 1 |
Cp-1411124 Lines Gp-Drain
| 14***24 | Lines Group-Drain | 1 |
Cp-1411126 Lines Gp-Drain
| 14***26 | Lines Group-Drain | 1 |
Cp-1384642 Lines Gp-Drain
| 13***42 | Lines Group-Drain | 1 |
Cp-1623223 Lines Gp-Front
| 16***23 | Lines Group-Front | 1 |
Cp-1623221 Lines Gp-Front
| 16***21 | Lines Group-Front | 1 |
Cp-1623224 Lines Gp-Pilot
| 16***24 | Lines Group-Pilot; Lines Gp-Pilot-C | 1 |
Cp-1623220 Lines Gp-Pilot
| 16***20 | Lines Group-Pilot; Lines Gp-Pilot-C | 1 |
Cp-1384636 Lines Gp-Rotator
| 13***36 | Lines Group-Rotator | 1 |
Cp-1411125 Lines Gp-Rotator
| 14***25 | Lines Group-Rotator | 1 |
Cp-1434561 Lines Gp-Rotator
| 14***61 | Lines Group-Rotator | 1 |
Cp-1411123 Lines Gp-Rotator
| 14***23 | Lines Group-Rotator | 1 |
Cp-1360058 Lines Gp-Rotator
| 13***58 | Lines Group-Rotator | 1 |
Cp-1446325 Pump & Mounting Gp
| 13***98 | Pump Group-Gear; -Medium Pressure | 1 |
| 14***25 | Pump & Mounting Group | 1 |
| 8T***23 | Washer-Hard; (13.5x25.5x3-mm Thk)(Bolt To Shield) | 4 |
Cp-6c6746 Valve Gp
| 6C***46 | Valve Group | 1 |
Cp-1443613 Valve Gp-Auxiliary Manifold
| 14***13 | Valve Group-Auxiliary Manifold | 1 |
Implements
Cp-1411115 Installation Ar.
| 14***15 | Installation Ar. | 1 |
Cp-1411122 Installation Ar.
| 14***22 | Installation Ar. | 1 |
Cp-1411118 Installation Ar.
| 14***18 | Installation Ar. | 1 |
Cp-1411111 Installation Ar.
| 14***11 | Installation Ar. | 1 |
Service Equipment & Supplies
Cp-1287866 Plate & Film Gp
| 12***66 | Film Group; Film Gp-Combined Function | 1 |
322B LN serial number reference
The PIN plate on a 322B LN is riveted to the machine frame, typically on the right side near the cab/swing-bearing mount, with a duplicate tag sometimes found under the operator seat or on the cab riser shelf. On this pre-2001 machine the PIN reads as 8 characters: a 3-letter prefix for the model/plant/production block followed by a 5-digit sequence number (for example 1ZS00001). Match the 3-letter prefix to the serial-break tables in the parts or service manual to confirm which build block, and which manual set, covers that specific unit.
| Prefix | Identifies | Notes |
|---|---|---|
| 1ZS | 322B LN | Gosselies (Belgium) built block, shared with 322B L under the same electrical and parts manual set. Cat 3116 turbocharged-aftercooled engine. Falls inside the roughly 1998-2002 production span documented for the LN chassis. Whether a given serial in this block is an L or LN configuration is not broken out in the indexes found - check the full PIN or ask a dealer. |
| 2ES | 322B LN | Gosselies (Belgium) built block, grouped with 1ZS under the combined 322B L/LN electrical schematic and parts manuals; a work-tool attachment listing keys specifically off this prefix against the LN excavator. Same 3116 engine and plant as the 1ZS block. Split between L and LN within this range is not separately documented - confirm exact configuration with a dealer. |
Frequently asked questions
What engine powers the Caterpillar 322B LN excavator?
The 322B LN uses the Cat 3116TA, a turbocharged, air-to-air aftercooled inline-six diesel displacing 6.6 L, with mechanical unit injection and no engine ECM. It's rated at roughly 120 kW (161 hp) gross and 114 kW (153 hp) net at 1950 rpm.
What is the operating weight of the 322B LN?
Operating weight runs roughly 23.8 to 24.8 t (about 52,500-54,700 lb) depending on boom, stick, and counterweight configuration and which spec sheet is checked. Most factory configurations land near 23.8 t (52,490 lb).
What replaced the Cat 322B LN?
Caterpillar replaced it with the 322C LN, built roughly 2002-2005 on the same long/narrow undercarriage layout but powered by the Cat 3126B engine with electronic unit injection and higher gross output.
What 322B LN owners discuss
What engine issues come up most with the 3116TA in the 322B LN, and are they generation-specific?
Engine loses power or stalls the moment the hydraulics are loaded — what's the usual cause?
What swing-circuit failures are typical on this excavator?
What electrical and sensor gremlins show up on 322B LN machines?
Hydraulics cut out on their own after the machine's been running a while, then come back after it cools down — what is that?
What undercarriage wear pattern is typical, and what does the LN suffix mean for it?
What should a buyer check specifically on a used 322B LN before purchase?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 322B LN part?
Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.