Home›Engines›John Deere 6068T

John Deere 6068T Engine

The John Deere 6068T is a 5.4 L 6-cylinder water cooled engine rated at 1800 rpm, producing up to 112 kW. It powers generator sets from John Deere, including the 6068TF120, ML100JDNKD and ML85JDNKD.

Also known as: John Deere 6068T

Part of the John Deere 6068 engine family — 92 variants share parts & fitment.

5.4 L
Displacement
6
Cylinders
1800 rpm
Rated speed
112 kW
Gross power

Engine specifications

Displacement5.4 L
Cylinders6
Aspirationwater cooled
Rated speed1800 rpm
Gross power112 kW

Generator sets powered by this engine

3
John Deere 6068TF120John Deere ML100JDNKDJohn Deere ML85JDNKD

How to read your John Deere engine serial & model number →

Service intervals

27
ItemActionHoursMonthsNotes
Engine Oil and Oil FilterChange250 hr6 moFirst service — First change before 100 hours maximum of break-in operation
Engine oil and filterChange100 hrFirst service — First service: change at maximum 100 hours of break-in operation
BatteryCheck250 hr6 moService battery
BatteryOther250 hr6 moService battery
Engine MountsCheck250 hr6 mo
Fire ExtinguisherOther250 hr250 Hour/6 Month; also inspect once a month
Fire extinguisherCheck250 hr6 moStandard industrial engines; at least once a month
Manual Belt Tensioner and Belt WearCheck250 hr6 mo
Air Intake Hoses, Connections, & SystemCheck500 hr12 mo
Automatic Belt Tensioner and Belt WearCheck500 hr12 mo
Coolant solution analysis - add SCAs as requiredTest500 hr12 moTest every 500 hours or 12 months
Cooling SystemCheck500 hr12 mo
Cooling SystemTest500 hr12 moPressure test cooling system
Crankcase Vent TubeClean500 hr12 moClean more often in dusty conditions
Engine Electrical Ground ConnectionCheck500 hr12 mo
Engine speedsCheck500 hr12 mo
Fuel Filter ElementReplace500 hr12 moBleed fuel system
Single or dual fuel filter elementsReplace500 hr12 mo
Cooling SystemOther2000 hr24 moFlush; with COOL-GARD extend to 3000 hours/36 months, or 5000 hours/60 months if tested annually and SCAs replenished
Cooling systemDrain2000 hr24 moFlush/refill; with COOL-GARD extend to 3000 hours or 36 months; to 5000 hours or 60 months if tested annually and SCAs replenished
Crankshaft vibration damper (6.8 L engines)Check2000 hr24 moReplace every 4500 hours or 60 months, whichever occurs first
Engine valve clearanceAdjust2000 hr24 moCheck and adjust
ThermostatsTest2000 hr24 mo
Variable speed (droop) (generator sets)Adjust2000 hr24 moGenerator (standby) applications
Engine coolantTest12 moTest the coolant solution at intervals of 12 months or less and whenever excessive coolant is lost
Supplemental coolant additiveCheck12 moReplenish additives between drain intervals by adding supplemental coolant additive every 12 months or as determined by coolant testing
Vibration damperReplace4500 hr60 moReplace every five years or 4500 hours, whichever occurs first

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

60
TypeItemValueUnitCondition
ClearanceAir Cleaner Neck to Engine Intake—Overlap38 mm (1.5 in)mm
ClearanceAssembled Rod Bearing—ID77.876—77.927mm (3.0659—3.0679 in.)
ClearanceCamshaft Follower Bore in Block—ID31.70—31.75mm (1.248—1.250 in.)
ClearanceCamshaft Follower-to-Bore—Clearance0.06—0.13mm (0.002—0.005 in.)
ClearanceCamshaft Follower—OD31.61—31.64mm (1.245—1.246 in.)
ClearanceConnecting Rod Bearing-to-Journal (New Parts)—Oil Clearance; wear limit 0.152 mm (0.0060 in.)0.050—0.127mm (0.0020—0.0050 in.)
ClearanceConnecting Rod Bore (Without Bearing Inserts)—ID82.677—82.703mm (3.2550—3.2560 in.)
ClearanceConnecting Rod Bore—Maximum Permissible Out-of-Round0.038mm (0.0015 in.)
ClearanceCrankshaft—End Play0.029—0.357mm (0.001—0.014 in.)
ClearanceCylinder Block Main Bearing Bore—ID84.455—84.481mm (3.3250—3.3260 in.)
ClearanceCylinder Head Flatness—Maximum Acceptable Out-of-Flat for Entire Length or Width0.08mm (0.003 in.)
ClearanceCylinder Head Flatness—Maximum Acceptable Out-of-Flat for Every 150 mm (5.90 in.)0.03mm (0.001 in.)
ClearanceCylinder Liner—Height above Block0.030—0.100mm (0.001—0.004 in.)
ClearanceCylinder Liner—ID106.48—106.52mm (4.192—4.194 in.)
ClearanceCylinder Liner—Maximum Taper0.05mm (0.002 in.)
ClearanceExhaust Valve Clearance For Adjusting (Rocker Arm-to-Valve Tip)0.46 mm (0.018 in.)mmengine COLD
ClearanceExhaust Valve Clearance For Checking (Rocker Arm-to-Valve Tip)0.41—0.48 mm (0.016—0.019 in.)mmengine COLD
ClearanceExhaust Valve Guide-to-Valve Stem (New) Clearance (four-valve)0.025—0.077mm (0.0010—0.0030 in.)
ClearanceExhaust Valve—Recess in Cylinder Head (four-valve); wear limit 1.81 mm (0.071 in.)0.81—1.31mm (0.032—0.052 in.)
ClearanceExhaust Valve—Recess in Cylinder Head (two-valve); wear limit 2.26 mm (0.089 in.)1.22—1.72mm (0.048—0.068 in.)
ClearanceFuel Supply Pump Push Rod Bore in Block—ID10.00—10.05mm (0.3937—0.3957 in.)
ClearanceFuel Supply Pump Push Rod—OD9.891—9.917mm (0.3894—0.3904 in.)
ClearanceFuel injection nozzle tip orifice ID0.27mm (0.0106 in.)Naturally aspirated engines
ClearanceFuel injection nozzle tip orifice ID0.29mm (0.0116 in.)Turbocharged engines
ClearanceFuel injection nozzle valve needle lift (based on zero lift)3/4 Turn CounterclockwiseturnConventional nozzle
ClearanceIntake Valve Clearance For Adjusting (Rocker Arm-to-Valve Tip)0.36 mm (0.014 in.)mmengine COLD
ClearanceIntake Valve Clearance For Checking (Rocker Arm-to-Valve Tip)0.31—0.38 mm (0.012—0.015 in.)mmengine COLD
ClearanceIntake Valve Guide-to-Valve Stem (New) Clearance (four-valve)0.012—0.064mm (0.0005—0.0025 in.)
ClearanceIntake Valves—Recess in Cylinder Head (four-valve); wear limit 1.77 mm (0.070 in.)0.77—1.27mm (0.030—0.050 in.)
ClearanceIntake Valves—Recess in Cylinder Head (two-valve); wear limit 1.63 mm (0.064 in.)0.61—1.11mm (0.024—0.044 in.)
ClearanceIntake and Exhaust Valve Guide-to-Valve Stem Wear Limit (four-valve)0.15mm (0.0059 in.)
ClearanceIntake and Exhaust Valves—Maximum Variation for a Pair of Valves (Per Cylinder)0.3mm (0.012 in.)
ClearanceMain Bearing Bore Centerline-to-Cylinder Block Top Deck—Distance337.896—337.972mm (13.3029—13.3059 in.)
ClearanceMaximum Permissible Height Difference at Nearest Point of Two Adjacent Liners, or Within a Single Liner0.05mm (0.002 in.)
ClearanceMaximum eccentricity.004in (0.10 mm) T.I.R.
ClearancePiston Pin-to-Bushing—Oil Clearance; wear limit 0.102 mm (0.0040 in.)0.020—0.056mm (0.0008—0.0022 in.)
ClearancePiston Rings 4045DF, TF150 and 6068DF, TF150 No. 1 Compression—End Gap0.33—0.58mm (0.013—0.023 in.)
ClearancePiston Rings 4045TF250 and 6068TF250 No. 2 Compression—End Gap0.75—1.00mm (0.030—0.039 in.)
ClearancePiston-to-Liner Clearance at Bottom of Piston Skirt (Naturally Aspirated Engines)0.08—0.14mm (0.003—0.005 in.)
ClearancePiston-to-Liner Clearance at Bottom of Piston Skirt (Turbocharged Engines)0.08—0.15mm (0.003—0.006 in.)
ClearanceRocker Arm Bore—ID (four-valve); wear limit 20.16 mm (0.794 in.)20.065—20.115mm (0.790—0.792 in.)
ClearanceRocker Arm Bore—ID (two-valve); wear limit 20.17 mm (0.794 in.)20.07—20.12mm (0.790—0.792 in.)
ClearanceRocker Arm Shaft—OD (four-valve); wear limit 19.91 mm (0.784 in.)19.962—20.038mm (0.786—0.789 in.)
ClearanceRocker Arm Shaft—OD (two-valve); wear limit 19.94 mm (0.785 in.)19.99—20.02mm (0.787—0.788 in.)
ClearanceValve Bridge—Pocket-to-Pocket Variation (Maximum)0.1mm (0.004 in.)
ClearanceValve Guide-to-Valve Stem (New) Clearance (two-valve); wear limit 0.15 mm (0.006 in.)0.05—0.10mm (0.002—0.004 in.)
ClearanceValve lift7/8turnRSN nozzle, Tier II certified engines
ClearanceVibration Damper—Maximum Radial Runout1.50 mm (0.060 in.)mmengine at operating temperature
ClearanceVibration damper maximum radial runout1.50mmengine at operating temperature
GapCalibrating injector orifice plate0.5mmSAE J968/ISO 7440
GapGovernor linkage gap.125-.165in (3.2-3.7 mm)use kit 23093 S.B. 95
GapMagnetic pick-up probe air gap to flywheel face0.64mm (0.025 in.)
GapRoller-to-roller dimension1.953 ± .0015in (49.61 mm ± 0.04 mm)
GapValve Face—Maximum Runout (Intake and Exhaust)0.038mm (0.0015 in.)
Injection timingAdvance check 15c0.5°MIN°875 RPM L.I.
Injection timingAdvance check 15d6.5°-7.5°°500 RPM WOT; cold start solenoid energized
Injection timingAdvance check 15e6.5°-7.5°°1500 RPM ADJ.; cold start solenoid energized
Injection timingAdvance check 15f0.25°-1.25°°1700 RPM WOT
Injection timingAdvance check 15h1.0°-2.0°°2100 RPM WOT
Injection timingAdvance check 15j2.5°-3.5°°1300 RPM ADJ.

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
CoolantEthylene glycol base coolantASTM D6210Freeze protection: 40%=-24°C (-12°F); 50%=-37°C (-34°F); 60%=-52°C (-62°F)
CoolantJohn Deere COOL-GARD II / COOL-GARD II PG pre-mixASTM D6210Or concentrate in 40—60% mixture with quality water. Do not use less than 40% or greater than 60% concentrate.
CoolantJohn Deere COOL-GARD Prediluted Coolant (50% ethylene glycol or 55% propylene glycol)ASTM D6210 prediluted/concentrate; ASTM D4985 requires initial SCA chargeSystem filled for freeze protection to -37°C (-34°F). Do not use coolant-water mixture greater than 60% glycol. Do not mix ethylene glycol and propylene glycol base coolants.
CoolantJohn Deere COOL-GARD Prediluted Coolant (preferred); John Deere COOL-GARD Coolant Concentrate 40-60% mixture with quality waterASTM D5345 (prediluted) / ASTM D4985 (concentrate)50% ethylene glycol provides freeze protection to -37°C (-34°F); 40% to -24°C (-12°F); 60% to -52°C (-62°F). Do not exceed 60%.
Engine oilJohn Deere ENGINE BREAK-IN OILAlternate: API CE, CD, CC or ACEA E2, E1 (first 100 hours)New/rebuilt engines filled at factory with break-in oil. Do not exceed 100 hours with break-in oil.
Engine oilJohn Deere PLUS-50 (preferred)ACEA E5, ACEA E4; also John Deere TORQ-GARD SUPREME, API CI-4, CH-4, CG-4, CF-4, ACEA E3, E2 (Non-Certified and Tier 1 Certified Engines)Multi-viscosity diesel engine oils are preferred. If oils meeting API CG-4, API CF-4, or ACEA E2 are used, reduce service interval by 50%.
Engine oilJohn Deere PLUS-50 (preferred); John Deere TORQ-GARD SUPREME (also recommended)API CI-4 / CH-4 / CG-4 / CF-4; ACEA E5 / E4 / E3 / E2Multi-viscosity diesel engine oils preferred. If fuel sulfur >0.5% (5000 ppm), reduce service interval by 50%. During first 100 hours of new/overhauled engine use John Deere ENGINE BREAK-IN OIL or API CD/CC or ACEA E1.
Engine oilSAE 10W-30 (if John Deere Break-In oil not available)API CE, CD, CC; ACEA E2 or E1Break-in oil; change oil and filter at maximum 100 hours. Do not use Plus-50 II or CJ-4/CI-4/CH-4 etc. for initial break-in.
Engine oilSAE 15W-40, SAE 10W-40, SAE 10W-30, SAE 5W-30, SAE 0W-40, SAE 30, SAE 40John Deere Plus-50 II (preferred), Plus-50, Torq-Gard; API CJ-4, CI-4 PLUS, CI-4, CH-4, CG-4, CF-4; ACEA E9, E7, E6, E5, E4, E3, E2Use oil viscosity based on expected air temperature range between oil changes. Reduce service interval by 50% if API CG-4, API CF-4 or ACEA E2 oils used.
FuelEN 590 or ASTM D975Cetane number 40 minimum (greater than 50 preferred, especially below -20°C (-4°F) or above 1500 m (5000 ft)). Cold Filter Plugging Point below expected low temperature or Cloud Point at least 5°C (9°F) below expected low temperature. Fuel lubricity should pass minimum 3100 gram load level (BOCLE scuffing test) / ASTM D6078 or max scar diameter 0.45 mm ASTM D6079 / ISO 12156-1. Sulfur content should not exceed 0.5% (less than 0.05% preferred); DO NOT use fuel with sulfur content greater than 1.0%. Do not mix used engine oil with diesel fuel.
Fuel5% blend (B5)ASTM D6751, EN 14214, or equivalentBio-diesel maximum allowable concentration is a 5% blend (B5) in petroleum diesel fuel. Check engine oil level daily when air temperature is -10°C (14°F) or lower. Raw pressed vegetable oils are NOT acceptable at any concentration.
FuelBio-diesel fuelASTM D6751, EN 14214 or equivalent; up to 5% blend (B5)Raw pressed vegetable oils are NOT acceptable. Check engine oil level daily when air temperature is -10°C (14°F) or lower.
FuelDiesel fuelEN 590 or ASTM D975; Cetane number 40 minimum (greater than 50 preferred) for Non-Certified, Tier I and Tier 2/Stage II enginesSulfur content should not exceed 0.5%; DO NOT use diesel fuel with sulfur content greater than 1.0%. Fuel lubricity minimum 3100 gram load (BOCLE).
FuelDiesel fuel per EN 590 or ASTM D975EN 590 / ASTM D975Cetane number 40 minimum, greater than 47 preferred below -20°C (-4°F) or above 1675 m (5500 ft). Max sulfur 10000 mg/kg (10000 ppm).
FuelGrade No. 1-D fuel usable below 5°C (40°F); Grade No. 2-D otherwiseEN 590 or ASTM D975Cetane number 45 minimum (>50 preferred). Lubricity min load 3100 grams (ASTM D6078) or max scar diameter 0.45 mm (ASTM D6079). Sulfur <0.05% (500 ppm) preferred; DO NOT use sulfur >1.0%. Bio-diesel per ASTM PS121 or DIN 51606, up to 5% blend.
FuelWinter grade fuel (No. 1-D in North America)below 0°CUse when temperatures fall below 0°C (32°F)
GreaseJohn Deere SD POLYUREA GREASE (preferred)NLGI Performance Classification GC-LB; also John Deere HD LITHIUM COMPLEX GREASE, HD WATER RESISTANT GREASE, GREASE-GARDConsult grease supplier before mixing different types of grease.
GreaseJohn Deere SD POLYUREA GREASE (preferred); HD MOLY GREASE, HD LITHIUM COMPLEX GREASE, HD WATER RESISTANT GREASE, GREASE-GARD (also recommended)NLGI Performance Classification GC-LBSome grease thickener types are not compatible; consult supplier before mixing.
OtherJohn Deere COOLANT CONDITIONER / Liquid Coolant Conditioner (supplemental coolant additive)Replenish between drain intervals every 12 months or as determined by coolant testing; premix 3% when precharging. DO NOT add SCA when drained and refilled with COOL-GARD.
OtherSAE J967/ISO 4113SAE J967/ISO 4113 (REF. S.B. 201)Calibration fluid temperature 110-115°F (43-46°C) at inlet; supply pressure 5.0 ± 0.5 PSI (34 ± 3 kPa) at pump inlet.

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
Adjust Fuel Injection Nozzles adjustment

⚠ Do not manually bottom the valve with excessive force; bending of the valve may result.

Tools: JDG949 Nozzle Wrench, JDG1515-2 Pressure Adjustment Screw Lock Nut Tool, JDG1522 Pressure Adjustment Screw Tool, JDG1521 Spring Chamber Cap Wrench

  1. Remove nozzle from tester and install in holding fixture.
  2. Remove lift adjusting lock nut.
  3. Loosen pressure adjusting screw lock nut using JDG949 Nozzle Wrench.
  4. Reconnect nozzle to tester with tip pointing downward.
  5. Back out lift adjusting screw two or three turns to prevent bottoming.
  6. Turn pressure adjusting screw in (clockwise) to increase opening pressure or out to decrease.
  7. Remove nozzle and secure in holding fixture; tighten pressure adjusting screw lock nut to 10 N•m (7 lb-ft).
  8. Adjust valve lift: turn lift adjusting screw in until valve ceases to open (conventional nozzle).
  9. Turn lift adjusting screw out 3/4 turn counterclockwise (based on zero lift); 1/8 turn tolerance permissible.
  10. Tighten lift adjusting screw lock nut to 5 N•m (3.5 lb-ft).
  11. Recheck nozzle opening pressure and chatter.
Adjusting Variable Speed (Droop) on Generator Set Engines (Stanadyne Mechanical Injection Pumps Only) adjustment
  1. Warm engine to normal operating temperature.
  2. When necessary, disconnect throttle linkage or cable.
  3. Adjust slow idle and adjust fast idle speed when necessary.
  4. Run engine at fast idle, then apply load until reaching rated speed.
  5. Check power. Adjust with the screw if needed.
  6. Remove load from engine.
  7. Again check and adjust fast idle if the droop screw has been turned.
  8. Repeat procedure until both the engine power and the fast idle speed are correct.
  9. Reinstall throttle linkage if previously removed.
Air timing pump using Hartridge tool adjustment

Tools: Hartridge basic air timing tool 7244-27, Insert 7244-30, Pilot ring 7244-26E

  1. Connect air supply at 60-100 PSI (4.1-6.9 BAR) to #1 cylinder outlet.
  2. Set Hartridge tool 7244-27 with insert 7244-30 and pilot ring 7244-26E to 208°.
  3. Install tool to drive shaft.
  4. Slowly rotate tool clockwise until rollers strike cam ring and tool stops.
  5. Scribe line on housing flange.
  6. Repeat procedure to ensure accuracy.
  7. If straight edge interferes with housing flange, place washer such as 13521 between straight edge and tool.
Check and Adjust Rotary Injection Pump Dynamic Timing adjustment

⚠ Stop engine prior to making timing adjustments; injection pump can seize if adjustment is made with engine running.

Tools: JT07158 (FKM10429A) TIME TRAC Kit, JT07177 Clamp-On Transducer, JT07172 Transducer Cable, JDG793 or JDG821 Magnetic Pick-Up Adapter, JDE81-4 or JDG1571 Timing Pin

  1. Install JT07158 (or FKM10429A) TIME TRAC Kit.
  2. Install transducer or in-line SOI sensor on No. 1 fuel injection line at nozzle end; use No. 4 or No. 6 line if access restricted.
  3. Install magnetic pick-up in flywheel timing hole with 0.64 mm (0.025 in.) air gap; do not stop engine at TDC.
  4. Engine OFF; push ON/CLEAR; select MAG PROBE, set Trig Level to 70%, press ENTER.
  5. Set Offset to 0 degrees and press ENTER.
  6. Start engine, press ENTER; run engine at 1300 rpm, press ENTER to calibrate.
  7. Warm engine to normal operating temperature; check slow and fast idle rpm; adjust as necessary.
  8. Run engine at wide open throttle and load engine down gradually to rated speed rpm.
  9. Record engine speed and timing degrees; compare to Section 06, Group 210 or machine technical manual.
  10. Stop engine; loosen injection pump mounting flange nuts and adjust pump timing.
  11. To advance timing rotate top of pump clockwise (viewed from rear/flywheel end); to retard rotate counterclockwise.
  12. Tighten injection pump mounting flange nuts to 27 N•m (20 lb-ft).
  13. Start engine and recheck dynamic timing; adjust as needed.
  14. Grind away original front plate timing mark and stamp a new mark aligned with injection pump flange mark.
Check and Adjust Slow Idle Speed—Denso Fuel Injection Pump adjustment

⚠ ALWAYS STOP ENGINE before making adjustments.

⚠ Bumper spring screw should not be used by itself to change engine speed more than 50 rpm.

Tools: Tachometer

  1. With engine running, pull governor control lever rearward to slow idle speed position; check speed.
  2. Remove slow idle stop screw cover.
  3. Loosen lock nut and back out bumper spring adjusting screw three turns.
  4. Loosen lock nut and adjust slow idle stop screw to obtain idle 30—50 rpm less than desired slow idle setting.
  5. Turn bumper spring adjusting screw in to increase engine speed a maximum of 30—50 rpm to desired slow idle.
  6. If surging persists, replace bumper spring and adjustment screw.
  7. Recheck fast and slow idle speeds; readjust slow idle if needed.
  8. Check all adjusting screw lock nuts for tightness; install covers.
  9. Connect fuel shut-off cable and speed control rod.
Check and Adjust Valve Clearance adjustment

⚠ Valve clearance MUST BE checked and adjusted with engine COLD.

⚠ To prevent accidental starting, always disconnect NEGATIVE (—) battery terminal.

Tools: JDE83 or JD81-1 Flywheel Turning Tool, JDG1571 or JDE81-4 Timing Pin, Feeler gauge, JDG966 Crankshaft Front/Rear Rotation Adapter

  1. Disconnect NEGATIVE (–) battery terminal. Remove rocker arm cover and crankcase ventilator tube.
  2. Remove plugs from timing/rotation hole and timing pin hole.
  3. Rotate flywheel in running direction until No. 1 cylinder is at TDC compression stroke.
  4. Insert timing pin in flywheel to lock engine.
  5. Check valve clearance to cold specifications.
  6. Loosen jam nut on rocker arm adjusting screw; turn screw until feeler gauge slips with slight drag.
  7. Hold adjusting screw and tighten jam nut to specification; recheck clearance.
  8. Replace rocker arm cover and crankcase ventilator tube.
Check and Adjust Valve Clearance (Four-Valve Head Engines) adjustment

⚠ Adjust with engine COLD

⚠ Replace valves, seats, springs and retainers in pairs; also replace bridge

Tools: JDE83 Flywheel Turning Tool, JDG1571 Timing Pin, Feeler gauge

  1. Disconnect NEGATIVE battery terminal.
  2. Remove rocker arm cover and crankcase ventilator tube.
  3. Remove plugs from timing/rotation hole and timing pin hole.
  4. Rotate flywheel until No. 1 cylinder is at TDC compression; insert timing pin.
  5. Loosen jam nut on rocker arm adjusting screw.
  6. Turn adjusting screw until feeler gauge slips with slight drag.
  7. Tighten jam nut to 27 N•m (20 lb-ft) and recheck clearance.
Check and Adjust Valve Clearance (Two-Valve Head Engines) adjustment

⚠ Valve clearance MUST be checked and adjusted with engine COLD

⚠ Disconnect NEGATIVE battery terminal to prevent accidental starting

Tools: JDE83 or JDE81-11 Flywheel Turning Tool, JDG1571 or JDE81-4 Timing Pin, Feeler gauge

  1. Disconnect NEGATIVE battery terminal.
  2. Remove rocker arm cover and crankcase ventilator tube.
  3. Remove plugs from engine timing/rotation hole and timing pin hole.
  4. Rotate flywheel until No. 1 cylinder is at TDC compression; insert timing pin.
  5. Loosen jam nut on rocker arm adjusting screw.
  6. Turn adjusting screw until feeler gauge slips with a slight drag.
  7. Tighten jam nut to 27 N•m (20 lb-ft) and recheck clearance.
Manual Belt Tensioner Adjustment adjustment

⚠ Do not pry against alternator rear frame.

Tools: JDG1341 Belt Tension Gauge

  1. Install JDG1341 Belt Tension Gauge on belt halfway between pulleys.
  2. Loosen cap screws (B) and (C).
  3. Slide alternator or tensioner bracket in slot to remove all excess slack.
  4. Stretch belt by prying outward on alternator front frame or tensioner bracket.
  5. Tighten cap screws (B) and (C).
  6. Run engine for ten minutes and immediately re-check belt tension per used belt specification.
  7. Reset belt tension as necessary.
Manual Belt Tensioner Adjustment Using Belt Tension Tool (Alternate Method For Engines Without Auxiliary Drive) adjustment

Tools: JDG1520 Belt Tension Tool, Torque wrench

  1. Loosen upper and lower alternator bracket cap screws. Keep lower cap screw snug enough to prevent excessive play.
  2. Insert JDG1520 Belt Tension Tool behind belt and over alternator mounting screw.
  3. Place torque wrench on belt tensioning tool at 90° to tool. Pivot alternator until desired torque is achieved.
  4. While holding tension with torque wrench, scribe a reference mark on alternator in line with notch on upper alternator bracket.
  5. Continue to hold tension and tighten upper alternator bracket cap screw.
  6. Check position of reference mark to see if alternator moved while tightening.
  7. Remove belt tension tool and tighten lower alternator bracket cap screw.
Pump settings following pump service adjustment

Tools: Kit 23093

  1. Set roller-to-roller dimension to 1.953 ± .0015 in (49.61 ± 0.04 mm); maximum eccentricity .004 in TIR.
  2. Set governor linkage gap to .125-.165 in (3.2-3.7 mm) using kit 23093.
  3. Operate at 1000 RPM WOT for 10 minutes to reach operating temperature and clear air.
  4. At 300 RPM WOT, unscrew advance cap 4 turns; bleed 30 seconds; retorque to 200-225 in. lbs.
  5. At 400 RPM WOT, check shut-off ≤4 mm³/stroke and minimum transfer pump lift 18 in. Hg (60 kPa).
  6. At 2100 RPM WOT, set transfer pump pressure 79-81 PSI (545-559 kPa), return oil 400-700 CC/MIN, housing pressure 8.5-13.5 PSI (59-93 kPa).
  7. At 1700 RPM WOT, set advance trimmer screw for 0.75°.
  8. At 300 RPM WOT, bleed advance cap as in step 4.
  9. At 1300 RPM WOT, set roller-to-roller fuel delivery 81.5-82.5 mm³/stroke.
  10. At 2100 RPM WOT, set torque screw fuel delivery 66-67 mm³/stroke.
  11. At 2300 RPM WOT, set high idle screw for 8-14 max mm³/stroke.
  12. At 875 RPM L.I., set low idle screw for 10-12 mm³/stroke.
  13. At 1300 RPM ADJ. 25 mm³/stroke, set light load advance adjusting screw for 3.0°.
  14. At 300 RPM WOT, bleed advance cap as in step 4.
  15. Check points per table 15a-15m.
Check Cold Start Advance System Operation—Rotary Pumps diagnostic

⚠ After checks are completed, return cold start circuits to original configuration to ensure proper injection pump timing and conformance to emission control standards.

Tools: JT07158 (FKM10429A) TIME TRAC Kit, Jumper wire

  1. Install JT07158 (FKM10429A) TIME TRAC Kit; checks must be performed on a cold engine.
  2. Verify voltage potential (12 or 24 volts) to the cold start solenoid.
  3. Disconnect wiring connector from the cold start advance solenoid.
  4. Start cold engine and run at 1200 rpm; check and record injection pump timing.
  5. Connect wiring connector to cold start advance solenoid.
  6. After approximately 30 seconds, check injection pump timing.
  7. Stanadyne: there should be a 7—10° increase in timing; Delphi/Lucas: a 7—10° decrease.
  8. If no change, service the cold start advance solenoid and valve, or have the injection pump serviced by an authorized ADS Diesel Repair Station.

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

Parts cataloged across the John Deere 6068 family

300
Part #DescriptionCategory
100-001Air FilterAir filter
24-21000Air FilterAir filter
60205MOUNT, CONTROL BOX - COMMONAir filter
85400737OUTER AIR FILTERAir filter
85400786INNER AIR FILTERAir filter
85403921AIR FILTER HEAVY DUTYAir filter
C03327Air CleanerAir filter
C03396AIR FILTERAir filter
G030077Air Cleaner Element (Engine) PrimaryAir filter
G030078Air Cleaner Element (Engine) SecondaryAir filter
GM100703Element, PrimaryAir filter
GM100704Element, SafetyAir filter
GM90735Air CleanerAir filter
GM91358Element, Air CleanerAir filter
GM92823Element, Air Cleaner SafetyAir filter
GM94203Heavy Duty Air CleanerAir filter
MQ-125-AIR-FILTERAir FilterAir filter
DZ114956ALTERNATORAlternator
DZ117503ALTERNATORAlternator
DZ123153ALTERNATORAlternator
LSA462M3AlternatorAlternator
RE505895ALTERNATOR (12V, 75A)Alternator
RE506196Alternator 12 Volt 55 AmpAlternator
RE533516ALTERNATORAlternator
RE533653ALTERNATORAlternator
RE533654ALTERNATORAlternator
RE537146ALTERNATOR (28V, 50A) (3142)Alternator
RE537507ALTERNATOR (12V, 90 A) (31AE)Alternator
RE537508ALTERNATORAlternator
RE550906ALTERNATORAlternator
RE555751ALTERNATORAlternator
RE558675ALTERNATORAlternator
RE558676ALTERNATORAlternator
RE558678ALTERNATORAlternator
RM100224ALTERNATOR (REMAN FOR RE505895) (12V, 75A) (3135)Alternator
SE501341(REMAN FOR AT161324, DZ114957) (3142)Alternator
SE502560(3164)Alternator
SE502628ALTERNATOR (REMAN FOR RE533654) (12V, 120A) (3141)Alternator
85402451VOLTAGE REGULATORAvr
8972824026Battery Acid charge Pb-Ca maintenance free, 24V - 1100 CCABattery
MQ-125-BATTERYBatteryBattery
85425460BELTBelt
DZ114929FAN BELT (LGTH = 1655 mm)Belt
DZ115455FAN BELT (LGTH = 1550 mm)Belt
DZ115812FAN BELT (LGTH = 1680 mm)Belt
DZ117267FAN BELT (LGTH = 1690 mm)Belt
DZ117268FAN BELT (LGTH = 1530 mm)Belt
DZ118556FAN BELTBelt
DZ118557FAN BELTBelt
DZ118558FAN BELTBelt
DZ118559FAN BELTBelt
DZ118560FAN BELTBelt
DZ118561FAN BELT; LGTH = 1750 mm (24JX)Belt
DZ118764FAN BELT (LGTH = 1525 mm)Belt
DZ118781FAN BELT (LGTH = 1700 mm)Belt
DZ118786FAN BELTBelt
DZ118815FAN BELT (LGTH = 1725 mm)Belt
DZ119018FAN BELTBelt
DZ119059FAN BELTBelt
DZ119060FAN BELT (LGTH = 1555 mm)Belt
DZ119061FAN BELT (LGTH = 1540 mm)Belt
DZ119062FAN BELTBelt
DZ119063FAN BELTBelt
DZ119416FAN BELTBelt
DZ119477FAN BELT (LGTH = 1565 mm)Belt
DZ119478FAN BELT (LGTH = 1570 mm)Belt
DZ119515FAN BELTBelt
DZ119516FAN BELTBelt
DZ119520FAN BELTBelt
DZ119521FAN BELTBelt
DZ119522FAN BELTBelt
DZ119530FAN BELT (LGTH = 1675 mm)Belt
DZ119531FAN BELTBelt
DZ119533FAN BELTBelt
DZ119715FAN BELTBelt
DZ121128FAN BELT; LGTH = 1725 mm (24JW)Belt
DZ121129FAN BELTBelt
DZ121133FAN BELTBelt
GM70424-1Fan Belt (12V)Belt
GM70424-2Fan Belt (24V)Belt
GM70798-1Fan BeltBelt
GM70798-2Fan BeltBelt
GM70798-3Fan BeltBelt
GM70798-4Fan BeltBelt
GM84749Fan BeltBelt
L114292FAN BELTBelt
MQ-125-BELTV-BeltBelt
R123308Drive Belt, L1066H Late Production and M1066H allBelt
R123437Drive Belt, LP-MP668T-H (with turbo)Belt
R123439Drive Belt, LP-MP445D (non-turbo)Belt
R123457Drive Belt LP-MP668T-H (with turbo, formerly #R123464)Belt
R123464Drive Belt, LP668D (non-turbo, replaces R123463)Belt
R134625FAN BELT (LGTH = 1645 mm)Belt
R500277FAN BELTBelt
RE518097Belt TensionerBelt
T282795FAN BELTBelt
T428692FAN BELT (LGTH = 1665 mm)Belt
T428724FAN BELT (LGTH = 1575 mm)Belt
T428725FAN BELTBelt
T428818FAN BELTBelt
T428820FAN BELT (LGTH = 1580 mm)Belt
T428822FAN BELTBelt
T428823FAN BELTBelt
T428825FAN BELTBelt
T428863FAN BELTBelt
VP64S17Pump BeltBelt
011064Cold Weather OperationCold weather operation
RM100100CONTROLLERController
RM100131CONTROLLERController
SE502800CONTROLLERController
SE502801CONTROLLER (REMAN FOR RE520953) (8498) (8420) (8414)Controller
362140-SMain controller circuit boardController board
950-1682Coolant filterCoolant filter
MOOOOO-20001QAuto START/STOP Engine Controller (ECU)ECM / ECU
RE522680Short Block Assembly (L-M1066H and NL1066H4)Engine
5990101Power switching device (contactor)Exerciser switch
950-1683Pilot Hydraulic FilterFilter
950-2002Secondary Fuel FilterFilter
MQ-125-FUEL-FILTERFuel FilterFilter
MQ-125-OIL-FILTEROil FilterFilter
85403756BATTERY ELECTROLYTEFluid
G122208Clarke Eng Fluid - 5 galFluid
G122209Clarke Eng Fluid -1 galFluid
MQ-125-COOLANTCoolantFluid
MQ-125-OILEngine OilFluid
TY22041John Deere ENGINE BREAK-IN OIL (SAE 10W-30)Fluid
24-51003Fuel Filter without Drain ValveFuel filter
24-51005Fuel Filter with Metal Drain ValveFuel filter
85400976FUEL FILTERFuel filter
85403525FUEL FILTER SEPARATORFuel filter
85431120FUEL FILTERFuel filter
950-2001Fuel FilterFuel filter
CO2775Element, Fuel Water SeparatorFuel filter
CO2776Element, Fuel Filter PrimaryFuel filter
DZ112918SECONDARY FUEL FILTERFuel filter
DZ115392Secondary Fuel FilterFuel filter
DZ122688SECONDARY FILTER ELEMENT (35E6)Fuel filter
DZ128543PRIMARY FUEL FILTERFuel filter
GM50006Fuel FilterFuel filter
GM50074Fuel Filter (primary)Fuel filter
P-205-003Fuel FilterFuel filter
RE509031Filter ElementFuel filter
RE5090362Fuel filterFuel filter
RE509208Filter Element (also order R113565)Fuel filter
RE520906PRIMARY FUEL FILTERFuel filter
RE522878Fuel filterFuel filter
RE541578CRANKSHAFT PULLEY AND DAMPER; OD = 190 mm (1343)Fuel filter
RE541922PRIMARY FUEL FILTERFuel filter
RE60021FINAL FUEL FILTERFuel filter
RE62419FUEL FILTERFuel filter
SE501934(16CB)Fuel injection nozzle
11-11013Gasket, Thermostat Cover MountingGasket
11-11023Gasket, Manifold to Expansion TankGasket
11-11043GasketGasket
11-21011GasketGasket
11-31031Gasket, Turbo Oil ReturnGasket
11-31615GasketGasket
11-31635Gasket, Turbo Exhaust (K27)Gasket
33702GASKET KITGasket
36476GASKET KITGasket
85401131ROCKER COVER GASKETGasket
DZ123559COMPLETE BLOCK ASSEMBLY INCLUDES CYLINDER HEAD WITH VALVES AND ROCKER ARM ASSEMBLY, COMPLETE GASKET KIT WITH FRONT AND REAR SEALSGasket
R116516Engine Cylinder Head GasketGasket
R123226Gasket, Water By-pass TubeGasket
R123345Gasket, Thermostat HousingGasket
R123354Gasket, Engine Oil PanGasket
R123417Gasket, Water PumpGasket
R123501GasketGasket
R123504Gasket, Remote Oil Filter AdapterGasket
R123525GasketGasket
R123543Gasket, Rocker Arm CoverGasket
R123570GasketGasket
R123572GasketGasket
R135896GasketGasket
R500374GasketGasket
R504882Gasket, Rocker Arm Cover MountingGasket
R53108Gasket, Starting MotorGasket
R90658Gasket, Exhaust ManifoldGasket
10000037182Clamp, hose - spring type CTB-27STHose
18-19501Hose 1-1/4" ID x 3-1/2" 3 Ply SiliconeHose
18-21016Hose, 2" I.D. x 1-3/4" 3 Ply SiliconeHose
18-31605Hose, 1-1/4 x 32" Wire ReinforcedHose
50332Hose, fuel .750 ID 35 PSI SAE 30R7Hose
60316Clamp, hose - SAE 032 (1.56-2.50)Hose
85401289RADIATOR TOP HOSEHose
85426005RADIATOR BOTTOM HOSEHose
GM62396Hose, ReducerHose
GM91647Hose, HumpHose
R128455Hose, Radiator InletHose
R128456Hose, Radiator OutletHose
25-11011Impeller with GasketImpeller
25-15704ImpellerImpeller
35104NOZZLE CLAMP ASSEMBLYInjector
85400893INJECTORInjector
RE48786Fuel Injector (with turbocharger, includes keys 2-3)Injector
RE519730Fuel InjectorInjector
RE60062Fuel Injector (without turbocharger, includes keys 2-3)Injector
Y5020DEF Dosing InjectorInjector
Y5021Fuel Injector HarnessInjector
223673Filter, oilOil filter
24-01002Oil FilterOil filter
352793Oil FilterOil filter
36881696ELEMENT, ENGINE OIL FILTEROil filter
950-1681Engine Oil FilterOil filter
C04521Element, Oil FilterOil filter
DZ118286OIL FILTEROil filter
GM32809FILTER, OILOil filter
GM64496Oil FilterOil filter
GM77161Oil FilterOil filter
GM86400Oil FilterOil filter
LF3703Lube, Spin-OnOil filter
P-175-002Oil FilterOil filter
RE504836OIL FILTEROil filter
RE539279ENGINE OIL FILTEROil filter
SE501813(REMAN FOR DZ100021) (5024)Oil pump
011068Status: Generator at Rest, Stop Mode, 22:31Service part / kit
011136DANGER Electrocution. Do not disable or modify the connection box door safety switch.Service part / kit
05-79650SoundshieldService part / kit
100REOZJ4Stationary non-emergency gen-setsService part / kit
12547Assembly, cam lock, qrtr turnService part / kit
12632Lug Door Safety Swtiches(2)Service part / kit
14203Block, terminal - 10 pos.Service part / kit
14204Kit, ground barService part / kit
17776THROTTLE SHAFT BUSHING REPLACEMENTService part / kit
18556Regulator, voltage - SE 350Service part / kit
18893Handle, lug doorService part / kit
18934Guard, potentiometerService part / kit
20-29601-1Element, Intake AftercoolerService part / kit
21-10000Zinc PlugService part / kit
21-10010Zinc AnodeService part / kit
22018Hinge, continuous - 10.25Service part / kit
22208Hinge, control panel - 28”Service part / kit
23025Light, interior control panelService part / kit
23093Governor linkage gap kitService part / kit
24-20015Crankcase Breather Filter, Left handService part / kit
24540Holder, manualService part / kit
25-19511Wear PlateService part / kit
25077Switch, toggle - 20A VACService part / kit
26229Kit, voltage adjustment pot w/wiresService part / kit
26431ESO MOUNTING AND GROUNDING KITService part / kit
26888PROTECTIVE SHIPPING CAPService part / kit
26891PROTECTIVE SHIPPING CAPService part / kit
27828Panel, lug box glasticService part / kit
28561WBox, lug enclosureService part / kit
28564WPanel, control leftService part / kit
28567Bus, main breaker outService part / kit
28569WPanel, lug box outletService part / kit
28570WDoor, lug boxService part / kit
28583WAngle, top lug boxService part / kit
28584Bus, lug extensionService part / kit
28653BWeldment, control boxService part / kit
28910SPRING, pressure adjustingService part / kit
29893Bracket, control board wire guideService part / kit
2x594Ampere ratingService part / kit
30175Decal, UN31A tank cautionService part / kit
30246WPanel, digital controlService part / kit
32966O.S. METERING VALVE AND ARM ASSEMBLYService part / kit
33002SEAT, springService part / kit
34195VALVE BODYService part / kit
34270COIL ASSEMBLYService part / kit
34488HOUSING AND ADVANCE PISTON KITService part / kit
36493HEAD AND ROTOR KITService part / kit
37055CSA SOLENOID KIT 12V NON-DELAYService part / kit
38411CONNECTOR, back-leakageService part / kit
51551Decal set, safetyService part / kit
51552Decal, high tempService part / kit
54-51006Drain Valve, MetalService part / kit
54005CAP, DEF FILLService part / kit
55104CAP, FUEL FILL 3.50 - GREENService part / kit
60020Nut, M8-1.25 sflg lockService part / kit
60062Screw, 10-32 x .750 pan phil, G2Service part / kit
60068Screw, 10-24X.500 pan philService part / kit
60145Nut, .375-16 ser flg lockService part / kit
60161Nut, .250-20 hx ser flgService part / kit
60168Screw, .312-18X.750 hx hdService part / kit
60175Screw, .250-20X.500 sflg hexService part / kit
60252Washer, #10 split lockService part / kit
60268Rivet, .188 dia. x .126 to .250 grip, SSService part / kit
60270Nut, 8-32 nylock, G6Service part / kit
60398Screw, 10-32 x .500 pan phil, SSService part / kit
60452Washer, .313 flat 1.125/1.0 bonded rubber, SSService part / kit
60473Rivet, 3/16Service part / kit
60478Screw, .375-16X2.000 hx hdService part / kit
60505Nut, .312-18 U-clip - long typeService part / kit
60507Screw, .312-18x1.0 std hex, SSService part / kit
60525Screw, 8-32X1.500 pan philService part / kit
6068HF120-183EngineService part / kit
60749Plug, hole .500 dia. whiteService part / kit
61045Nut, 10-32 sflgService part / kit
65309Connector, 21 pin, deutschService part / kit
65444Transformer, currentService part / kit
655KGround Contact AreaService part / kit
65890Lug, terminal dual #6-350mcmService part / kit
66191Controller, eng/gen - prog.Service part / kit
66455Relay, 12V/70A NC/80A NO w/diodeService part / kit
80REOZJ4Stationary non-emergency gen-setsService part / kit
85401081COOLANT HEATER RESISTANCE 1000W 240VService part / kit
85403616ELECTRONIC ACTUATORService part / kit
85403731STARTING BATTERY 12V 100Ah 450AService part / kit
85404267AIR HEATER RESISTANCE 1200W 12VService part / kit

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Aftermarket parts that fit this engine

55
RE543266 SinoCMP $179.00 FridayParts $255.15 RE523502 Amazon eBay $213.99 NAPA $270.78 FridayParts $187.69 SinoCMP $339.00 AL114430 FridayParts $97.50 RE48786 Amazon eBay $44.95 FridayParts $105.00 AT112393 Amazon eBay $50.00 FridayParts $79.90 KuduParts $107.00 RE59277 FridayParts $139.59 RE505100 FridayParts $139.59 AR65507 Amazon eBay $12.00 FridayParts $27.20 RE507758 FridayParts $1498.68 RE533505 FridayParts $146.88 SinoCMP $189.00 RE534111 FridayParts $146.88 SinoCMP $189.00 RE522542 eBay FridayParts $94.27 SE501181 FridayParts $94.27 36713DR FridayParts $94.27 RE65912 FridayParts $32.99 RE55390 FridayParts $50.09 T46317 FridayParts $43.69 RE33885 FridayParts $43.69 P776696 FridayParts $56.50 6005024536 FridayParts $115.80 AR80653 Amazon eBay $86.29 FridayParts $108.97 AR80652 Amazon eBay $98.99 FridayParts $108.97 7700068425 FridayParts $326.56 616RZ FridayParts $326.56 RE515037 FridayParts $1498.68 RE521616 FridayParts $126.84 RE527039 FridayParts $310.20 RE55512 FridayParts $389.00 RE505102 FridayParts $1475.70 AT318160 Amazon eBay $52.25 KuduParts $107.00 F435201 KuduParts $107.00 F435511 KuduParts $107.00 RE43231 KuduParts $107.00 P566990 KuduParts $128.00 FridayParts $132.85 55200077 KuduParts $128.00 ST1154 KuduParts $128.00 74039 KuduParts $128.00 SH74039 KuduParts $128.00 7225312 KuduParts $128.00 861015 KuduParts $128.00 DER852V2C05 KuduParts $128.00 30TR850H6LLLA KuduParts $128.00 FP102789 KuduParts $128.00 4ZTA9 KuduParts $128.00 F061786 KuduParts $128.00 MP4727 KuduParts $128.00 H0850R006EB3V KuduParts $128.00 42212912 KuduParts $128.00 WHE20509 KuduParts $128.00 R102846 FridayParts $199.90 R91403 FridayParts $199.90 FP-XP-0012330 FP-XP-0001286 FP-XP-0000836 FP-XP-0000288

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
  • John Deere 200LC — Excavator
  • John Deere 360DC — Skid Steer Loader
  • John Deere 360DG — Skid Steer Loader
  • John Deere 460DG — Skidder
  • John Deere 540G II — Skidder
  • John Deere 540G III — Skidder
  • John Deere 548G — Skidder
  • John Deere 548G II — Skid Steer Loader
  • John Deere 640D — Skid Steer Loader
  • John Deere 648D — Skidder
  • John Deere 790E LC — Excavator
  • John Deere 9400 — Combine

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

What is the displacement of the John Deere 6068T?

The John Deere 6068T has a displacement of 5.4 liters with 6 cylinders.

Which generators use the John Deere 6068T engine?

The John Deere 6068T powers 3 generator set(s), including John Deere 6068TF120, John Deere ML100JDNKD, John Deere ML85JDNKD.