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Caterpillar D 343 Engine

The Caterpillar D 343 is a 6-cylinder four stroke cycle, diesel engine rated at 2000 rpm, producing up to 488.5 kW. It powers generator sets from Caterpillar, including the 200TH2608 and D343.

Also known as: Caterpillar D 343

6
Cylinders
2000 rpm
Rated speed
488 kW
Gross power

Engine specifications

Cylinders6
Aspirationfour stroke cycle, diesel
Rated speed2000 rpm
Gross power488 kW

Service intervals

15
ItemActionHoursMonthsNotes
SystemTest1 hrToCI quarterly: exercise system under full load for 1 hour
BatteryTest6 moLoad-test battery at each semi-annual visit
Coolant antifreezeChange12 moNCCI/RCI: antifreeze change once per year during contract term
Engine tune-upOther12 moAnnual: engine tune-up with parts
Fuel filtersChange12 moAnnual: change fuel filters
Generator sets and associated systemsInspect6 moSemi-annual inspection, testing and preventive maintenance (default unless Appendix A states otherwise)
Load bankTest12 moAnnual four (4) hour load bank test / emergency service operation with four (4) hours full load test once per year
Lube oilChange12 moCMC/HCF: additional services on second visit - lube, oil and filter change
Lube oil analysisTest12 moAnnual: lube oil analysis
OilChange12 moNCCI/RCI: oil shall be changed once every 12 months
Oil filter, fuel filter and air filterChange12 moNCCI: change once every 12 months during the contract period
Primary and bypass lube filtersChange12 moAnnual: change primary and bypass lube filters
Transfer switchLubricate12 moToCI annual: check, clean and lubricate transfer switches and breakers
Valve clearanceAdjust12 moToCI annual: check valve clearance
Water filtersChange12 moAnnual: change water filters

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

20
TypeItemValueUnitCondition
ClearanceCrankshaft end play.178 to .635mm (0.0070 to 0.0250 inch)measured with dial indicator
ClearanceCrankshaft end play after assembly0.178 to 0.635mm (0.0070 to 0.0250 inch)after assembly
ClearanceEnd play at heat sink after assembly0.076 to 0.635mm (0.0030 to 0.0250 inch)after assembly
ClearanceGap at 3, 6, 9, 12 o'clock positions0.03 to 0.13mm (0.001 to 0.005 inch)between
ClearanceGap between generator and flywheel housing at locations (E), (F), (G), (H)>0.03 and <0.13mm (0.001 inch to 0.005 inch)more than 0.03 mm and less than 0.13 mm
ClearanceGenerator forward offset from midpoint of end play+ 0.50mm (+ 0.0200 inch)while generator supported by crane
ClearanceRotor end play3.81 to 7.62mm (.150 to .300 inch)approximately
ClearanceShim thickness divisor for number of shims0.8mm (0.03 inch)divide Letter L by this value
ClearanceSupport deflection during bolt tightening0.13mm (0.005 inch)maximum allowed movement
OtherExercise under full load1hourToCI quarterly
OtherFull load test duration4hoursOnce per year
OtherLoad bank data recording interval15minutesDuring load bank test
OtherLoad bank test load level80% of generator nameplate capacity4-hour resistive load bank test
OtherLoad bank test profile2 hours at 50%, 1 hour at 75%, 1 hour at 100%Annual four (4) hour load bank test
TorqueBolts (10)100N-m (75 lb ft)Tighten in pairs at 180 degree intervals in three stages
TorqueBolts (7) for shim pack and plate assembly525 + 45N-m (390 + 30 lb ft)Tighten bolts (7)
TorqueCoupling plate assembly bolts (5)525 + 25N-m (390 + 20 lb ft)Tighten in 180 degree intervals in three stages
TorqueFan mounting bolts (11)200N-m (150 Ib ft)Tighten in pairs at 180 degree intervals in three stages
TorqueGenerator mounting bolts (half of standard torque)450N-m (332 lb ft)one half of standard torque
TorqueGenerator support bolts (half of final torque)450N-m (332 Ib ft)half of final torque

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Engine oilmeeting manufacturer's specsAdd crankcase oil (grade meeting manufacturer's specs) to correct level (SCI)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

12
Alignment Of Electric Sets With Supports At The Flywheel Housing / Installation Of A New Generator Or Flexible Plates adjustment

Tools: crane, dial indicator, shims, torque wrench

  1. Loosen all bolts connecting base to foundation; loosen all bolts fastening engine supports and generator supports to base.
  2. Ensure enough clearance between bolts and bolt holes in base, engine supports, generator supports at all locations.
  3. Check clearance between base and foundation at all mounting locations; use shims to prevent deflection; tighten base-to-foundation bolts to final torque.
  4. While generator supported by crane, loosen all bolts (2) fastening generator to flywheel housing; tighten alternate bolts to final torque; check clearance between base and engine and generator support
  5. Tighten all bolts fastening engine supports and generator supports to base to half of final torque; loosen all bolts (2); measure gap between generator and flywheel housing; ensure bolts centered in c
  6. Gaps at (E), (F), (G), (H) should be more than 0.03 mm (0.001 inch) and less than 0.13 mm (0.005 inch); adjust shims or move rear of generator right or left.
  7. After shim correction, tighten generator support bolts to half of final torque 450 N-m (332 Ib ft); check gaps; repeat until 0.13 mm (0.005 inch) or less; begin with Step 5.
  8. Install dial indicator on base with tip next to support mounting bolt (4); put tip on support (3); check while tightening bolt to final torque; if indicator moves more than 0.13 mm (0.005 inch), insta
Alignment Of Electric Sets Without Supports At The Flywheel Housing adjustment

Tools: shims, torque wrench

  1. Loosen all bolts connecting base to foundation; loosen all bolts fastening generator supports and engine supports to base.
  2. Ensure clearance between bolts and bolt holes in base, engine supports, generator supports at all locations.
  3. Check clearance between base and foundation at all mounting locations; use shims to prevent base deflection; tighten base-to-foundation bolts to final torque.
  4. Check clearance between base and engine, base and engine supports, base and generator supports over entire length; use shims to prevent support deflection; tighten all mounting bolts to final torque.
Rechecking The Alignment adjustment

Tools: torque wrench, shims

  1. Loosen the sixteen close coupled adapter bolts (2); visually ensure they are centered in clearance holes.
  2. Check gaps at 3, 6, 9, and 12 o'clock positions; use 2, 4, 8, and 10 o'clock if 12 and 6 are inaccessible.
  3. If gaps are between 0.03 mm (0.001 inch) and 0.13 mm (0.005 inch), tighten all bolts; alignment check complete. If not, loosen bolts fastening generator to base frame; adjust shims; move rear of gener
  4. After adjustment, tighten generator mounting bolts to one half of standard torque 450 N-m (332 lb ft); repeat procedure starting with Step 1.
Installation Of The Generator For Generator Sets That Are Equipped With A 3500 Engine installation

⚠ Damage to engine and generator can result if electric set is operated with a plate assembly that does not have proper clearance.

⚠ If N or O is less than initial A, disassemble and check coupling plate for bowing; replace if bowed.

Tools: dial indicator, straight edge, magnetic bases, crane, torque wrench, 17 5N-4478 Plates

  1. Ensure generator is disengaged from engine; clean generator support and base contact surfaces; remove protective material from flywheel pilot bearing bore and coupling contact surface.
  2. Remove two engine side covers; rotate engine until no. 1 crankshaft throw is perpendicular; measure crankshaft end play with dial indicator; record as A and divide by two for B.
  3. With crankshaft at extreme forward position, measure distance from straight edge to flywheel housing mounting surface (C) and flywheel pilot surface (D); subtract D from C for E.
  4. Remove coupling bolts and washers; remove plates, shims, and exhaust fan; lift rotor; locate rotor so air gap equal; move rotor to extreme rear.
  5. Place dial indicator on vertical surface of heat sink at rear of rotor shaft; measure rotor end play (approximately 3.81 to 7.62 mm); record F and divide by two for G.
  6. Move rotor to extreme rear; position straight edge across mounting ring diameter; measure distance to mounting ring surface (H) and hub mounting surface (I); subtract H from I for J.
  7. Bolt a standard set of 17 5N-4478 Plates together; measure thickness in two locations along contour; average as K.
  8. Determine number of shims: subtract B, E, G, K from J for L; divide L by 0.8 mm (0.03 inch) for M; round up.
  9. Put coupling plate in flywheel bore; check clearance between coupling plate outside diameter and flywheel bore inside diameter.
  10. Install coupling plate assembly, bolts (6) and calculated shims; tighten bolts (5) in 180 degree intervals in three stages to 525 + 25 N-m (390 + 20 lb ft).
  11. Install guide bolts in flywheel; put generator on engine; install bolts (10); tighten to 100 N-m (75 lb ft) in pairs at 180 degree intervals in three stages.
  12. While crane supports generator, place dial indicator on heat sink vertical surface; push generator forward within + 0.50 mm (+ 0.0200 inch) of midpoint of end play.
  13. Install fan mounting bolts (11) into flywheel; tighten to 200 N-m (150 Ib ft) in pairs at 180 degree intervals in three stages.
  14. Place dial indicators on no. 1 crankshaft throw and heat sink; push crankshaft forward; check crankshaft end play 0.178 to 0.635 mm and heat sink end play 0.076 to 0.635 mm; record N and O.
  15. If N or O is less than initial A, disassemble; check coupling plate for bowing; replace if bowed; check calculations; install generator and repeat steps 13 and 15.
Installation Of The Generator For Generator Sets That Are Not Equipped With A 3500 Engine installation

⚠ Damage to engine and generator can result if electric set is operated with a plate assembly that does not have proper clearance.

Tools: dial indicator, indicator assembly, bar, torque wrench, guide bolt, crane

  1. Remove dirt, burrs, paint from generator support and base contact surfaces; remove protective material from flywheel pilot bearing bore and coupling contact surface.
  2. Remove timing pointer cover; install indicator assembly on front of engine; tip contacts crankshaft pulley face.
  3. Position plate assembly in flywheel bore; check clearance between plate outside diameter and bore inside diameter.
  4. Install full shim pack and plate assembly on generator with bolts; tighten bolts to 525 + 45 N-m (390 + 30 lb ft).
  5. Install guide bolt in flywheel; put generator on engine; install bolts (9) and (10); tighten but do not bend locks under bolts (8).
  6. Use dial indicator to check crankshaft end play; if reading differs from initial, remove generator and enough shims to get original end play.
  7. Install generator again and check crankshaft end play; after correct shims, bend locks under bolts (8).
Automatic Transfer Switch Semi-Annual Service maintenance
  1. Verify proper operation of exerciser clock; adjust if necessary.
  2. Provide visual inspection of all contacts and connection points.
  3. Perform building load test if practical and inspect for proper transfer and re-transfer.
  4. Verify operation of all control lamps.
Battery and Battery Charger System Semi-Annual Service maintenance
  1. Clean all battery terminals; verify integrity of cables and connectors.
  2. Load-test battery.
  3. Measure specific gravity of each battery cell.
  4. Inspect electrolyte level and add fluid if necessary.
  5. Verify proper operation and float voltage of external battery charger.
  6. Verify and record output of engine alternator.
Controls Semi-Annual Service maintenance
  1. Verify and record output voltage and adjust voltage regulator, if necessary.
  2. Calibrate control meters.
  3. Verify and record output frequency and adjust governor, if necessary.
  4. Verify operation of all control panel lamps.
  5. Inspect for any loose connections, terminals or discoloration.
Coolant System Semi-Annual Service maintenance
  1. Inspect all clamps, verify condition of all hoses and identify any leaks.
  2. Verify proper operation of engine water jacket heater.
  3. Test coolant freeze point and verify coolant level.
  4. Test coolant additive package for proper corrosion inhibitors.
  5. Inspect belt condition and tension; correct as required.
  6. Inspect radiator core for visual blockage or obstructions.
  7. Inspect for proper operation of intake louvers.
  8. Verify proper operation of remote radiator and belt condition.
Cooling System Semi-Annual Service (SCI) maintenance
  1. Visual inspection of Radiator/Heat exchanger for leaks, damage and obstructions.
  2. Add coolant to correct level.
  3. Inspect radiator cap, gasket and sealing surface.
  4. Visual inspection of water pump and cooling system gaskets for leaks.
  5. Inspect belts for cracking and fraying.
  6. Check water jacket heater for proper operation and adjust thermostat setting as needed.
  7. Check belt tension.
  8. Inspect flexible water connections for cracking, leaks and pliability.
  9. Inspect pulleys for excessive wear.
  10. Analyze coolant for proper antifreeze percentage.
  11. Analyze coolant conditioner level and add supplemental coolant additive as needed.
  12. Tighten hose clamps as needed.
  13. Lubricate fan drive with bearing lubricant.
Engine Semi-Annual Service maintenance
  1. Verify and record oil pressure and water temperature.
  2. Test all safety shutdown circuits and alarms (overspeed, overcrank, low oil pressure, high water temp, low coolant level).
  3. Inspect air intake system (air filter, crankcase breather, turbocharger).
  4. Inspect muffler system and drain condensation trap; verify rain cap operation.
  5. Inspect engine starting system; verify cable integrity and connections.
  6. Inspect exhaust flex coupling and piping for leaks and proper connection.
  7. Check for abnormal vibration or noise.
  8. Inspect spark plugs, plug wires and distributor.
Fuel System Semi-Annual Service maintenance
  1. Inspect all fuel lines and hoses for leaks and general condition.
  2. Inspect day tank and float assembly for proper operation and leaks.
  3. Inspect fuel pump for leaks.
  4. Verify proper operation of governor and governor linkage.
  5. Check fuel level in primary supply tank.
  6. Drain water and sediment from fuel filter and fuel supply tanks.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Aftermarket parts that fit this engine

24

Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.

Also used in

12
  • Caterpillar 657B — Scraper
  • Gardner Denver 1200 — Compressor
  • Gardner Denver SP1200 — Compressor
  • Gardner Denver SP900 — Compressor
  • Manitowoc 3000 — Dragline
  • Manitowoc 3100 — Dragline
  • Manitowoc 3400 — Dragline
  • Manitowoc 3600 — Dragline
  • Manitowoc 3900 — Dragline
  • Manitowoc 4000 — Dragline
  • Manitowoc 4500 — Dragline
  • Manitowoc 4600 — Dragline

Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.

Common questions

Which generators use the Caterpillar D 343 engine?

The Caterpillar D 343 powers 2 generator set(s), including Caterpillar 200TH2608, Caterpillar D343.