John Deere 6068TF250 — Specs, Engine, Parts & Maintenance

Service parts for the 6068TF250

Grouped by system, with how many of each the parts manual calls for.

Oil system

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Frequency	60.0 Hz
Standby power	100 kW
Oil capacity	6.2 L
Alternator	Mecc Alte ECO 34-2L
Voltage options	240 V, 208 V, 480 V
Phase	1ph,3ph
Rated current	360 A
Power factor	0.8
Circuit breaker	50 A
Battery cranking	925 CCA
Battery voltage	12 V
Battery quantity	925
Coolant capacity	7.4 L
Max ambient	63 °C
Dry weight	4860 kg
Fuel tank	70.0 L

Engine

John Deere 6068TF250

Displacement	6.8 L
Aspiration	Turbocharged
Rated speed	1800 rpm

Filters for the John Deere 6068TF250

Engine-mounted filters the filter manufacturers list for this engine family. These come from the engine, not from this generator set’s own parts list, so confirm against your serial number before ordering.

System	Filter	Description	Cross-references
Oil filter	P550779	Lube Filter, Spin-On Full Flow	JOHN DEERE RE504836, JOHN DEERE RE50486, NAPA 7750S, SKYJACK 13502869	KuduParts $19.00
Oil filter	P551352	Lube Filter, Spin-On Full Flow	JOHN DEERE DZ118286, JOHN DEERE PMLF3703, NAPA 401062, BALDWIN B40168	buy
Fuel filter	P550090	Fuel Filter, In-Line	JOHN DEERE AE20952, JOHN DEERE AT101565, ASV INCORPORATED 0201914, LOESING 025125	FridayParts $45.66
Fuel filter	P551130	Fuel Filter, Box	JOHN DEERE AR50041, JOHN DEERE R16951, NAPA 3370, BALDWIN BF909	KuduParts $37.00
Fuel / water separator	P551424	Fuel Filter, Water Separator Spin-On	JOHN DEERE RE503198, JOHN DEERE RE522868, NAPA 3532, NAPA 600094	KuduParts $16.00 FridayParts $18.50
Fuel / water separator	P551422	Fuel Filter, Water Separator Cartridge	JOHN DEERE AT274723, JOHN DEERE RE22878, NAPA 3978, CLAAS 0011318200	KuduParts $22.00 FridayParts $24.50

Same engine, other brands

3 brands

The John Deere 6068TF250 in this set also powers 4 generator sets sold under 3 other brands. Service parts and maintenance intervals for the engine are shared; enclosure, alternator, controller and ratings are not.

Brand	Models
MQ Power	DCA-125SSJU, DCA-125SSJU2
Atlas Copco	QAS 108
Kohler	100REOZJ

Maintenance & consumables

for the John Deere 6068TF250

Item	Spec	Part #	Interval
Fuel filter		—	500 hr
Oil filter	last changed 7-26-23	GM32809		Amazon Amazon Amazon Amazon eBay $26.25 NAPA $28.76
Battery		—
Belt		—	250 hr
Coolant	-35F	—
Coolant filter		—
Oil		—	500 hr
Spark plug		—	500 hr

Service intervals

Item	Action	Hours	Months	Notes
Engine Oil and Oil Filter	Change	250 hr	6 mo	First service — First change before 100 hours maximum of break-in operation
Engine oil and filter	Change	100 hr		First service — First service: change at maximum 100 hours of break-in operation
Battery	Check	250 hr	6 mo	Service battery
Battery	Other	250 hr	6 mo	Service battery
Engine Mounts	Check	250 hr	6 mo
Fire Extinguisher	Other	250 hr		250 Hour/6 Month; also inspect once a month
Fire extinguisher	Check	250 hr	6 mo	Standard industrial engines; at least once a month
Manual Belt Tensioner and Belt Wear	Check	250 hr	6 mo
Air Intake Hoses, Connections, & System	Check	500 hr	12 mo
Automatic Belt Tensioner and Belt Wear	Check	500 hr	12 mo
Coolant solution analysis - add SCAs as required	Test	500 hr	12 mo	Test every 500 hours or 12 months
Cooling System	Check	500 hr	12 mo
Cooling System	Test	500 hr	12 mo	Pressure test cooling system
Crankcase Vent Tube	Clean	500 hr	12 mo	Clean more often in dusty conditions
Engine Electrical Ground Connection	Check	500 hr	12 mo
Engine speeds	Check	500 hr	12 mo
Fuel Filter Element	Replace	500 hr	12 mo	Bleed fuel system
Single or dual fuel filter elements	Replace	500 hr	12 mo
Cooling System	Other	2000 hr	24 mo	Flush; with COOL-GARD extend to 3000 hours/36 months, or 5000 hours/60 months if tested annually and SCAs replenished
Cooling system	Drain	2000 hr	24 mo	Flush/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)	Check	2000 hr	24 mo	Replace every 4500 hours or 60 months, whichever occurs first
Engine valve clearance	Adjust	2000 hr	24 mo	Check and adjust
Thermostats	Test	2000 hr	24 mo
Variable speed (droop) (generator sets)	Adjust	2000 hr	24 mo	Generator (standby) applications
Engine coolant	Test		12 mo	Test the coolant solution at intervals of 12 months or less and whenever excessive coolant is lost
Supplemental coolant additive	Check		12 mo	Replenish additives between drain intervals by adding supplemental coolant additive every 12 months or as determined by coolant testing
Vibration damper	Replace	4500 hr	60 mo	Replace 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

Type	Item	Value	Unit	Condition
Clearance	Air Cleaner Neck to Engine Intake—Overlap	38 mm (1.5 in)	mm
Clearance	Assembled Rod Bearing—ID	77.876—77.927	mm (3.0659—3.0679 in.)
Clearance	Camshaft Follower Bore in Block—ID	31.70—31.75	mm (1.248—1.250 in.)
Clearance	Camshaft Follower-to-Bore—Clearance	0.06—0.13	mm (0.002—0.005 in.)
Clearance	Camshaft Follower—OD	31.61—31.64	mm (1.245—1.246 in.)
Clearance	Connecting Rod Bearing-to-Journal (New Parts)—Oil Clearance; wear limit 0.152 mm (0.0060 in.)	0.050—0.127	mm (0.0020—0.0050 in.)
Clearance	Connecting Rod Bore (Without Bearing Inserts)—ID	82.677—82.703	mm (3.2550—3.2560 in.)
Clearance	Connecting Rod Bore—Maximum Permissible Out-of-Round	0.038	mm (0.0015 in.)
Clearance	Crankshaft—End Play	0.029—0.357	mm (0.001—0.014 in.)
Clearance	Cylinder Block Main Bearing Bore—ID	84.455—84.481	mm (3.3250—3.3260 in.)
Clearance	Cylinder Head Flatness—Maximum Acceptable Out-of-Flat for Entire Length or Width	0.08	mm (0.003 in.)
Clearance	Cylinder Head Flatness—Maximum Acceptable Out-of-Flat for Every 150 mm (5.90 in.)	0.03	mm (0.001 in.)
Clearance	Cylinder Liner—Height above Block	0.030—0.100	mm (0.001—0.004 in.)
Clearance	Cylinder Liner—ID	106.48—106.52	mm (4.192—4.194 in.)
Clearance	Cylinder Liner—Maximum Taper	0.05	mm (0.002 in.)
Clearance	Exhaust Valve Clearance For Adjusting (Rocker Arm-to-Valve Tip)	0.46 mm (0.018 in.)	mm	engine COLD
Clearance	Exhaust Valve Clearance For Checking (Rocker Arm-to-Valve Tip)	0.41—0.48 mm (0.016—0.019 in.)	mm	engine COLD
Clearance	Exhaust Valve Guide-to-Valve Stem (New) Clearance (four-valve)	0.025—0.077	mm (0.0010—0.0030 in.)
Clearance	Exhaust Valve—Recess in Cylinder Head (four-valve); wear limit 1.81 mm (0.071 in.)	0.81—1.31	mm (0.032—0.052 in.)
Clearance	Exhaust Valve—Recess in Cylinder Head (two-valve); wear limit 2.26 mm (0.089 in.)	1.22—1.72	mm (0.048—0.068 in.)
Clearance	Fuel Supply Pump Push Rod Bore in Block—ID	10.00—10.05	mm (0.3937—0.3957 in.)
Clearance	Fuel Supply Pump Push Rod—OD	9.891—9.917	mm (0.3894—0.3904 in.)
Clearance	Fuel injection nozzle tip orifice ID	0.27	mm (0.0106 in.)	Naturally aspirated engines
Clearance	Fuel injection nozzle tip orifice ID	0.29	mm (0.0116 in.)	Turbocharged engines
Clearance	Fuel injection nozzle valve needle lift (based on zero lift)	3/4 Turn Counterclockwise	turn	Conventional nozzle
Clearance	Intake Valve Clearance For Adjusting (Rocker Arm-to-Valve Tip)	0.36 mm (0.014 in.)	mm	engine COLD
Clearance	Intake Valve Clearance For Checking (Rocker Arm-to-Valve Tip)	0.31—0.38 mm (0.012—0.015 in.)	mm	engine COLD
Clearance	Intake Valve Guide-to-Valve Stem (New) Clearance (four-valve)	0.012—0.064	mm (0.0005—0.0025 in.)
Clearance	Intake Valves—Recess in Cylinder Head (four-valve); wear limit 1.77 mm (0.070 in.)	0.77—1.27	mm (0.030—0.050 in.)
Clearance	Intake Valves—Recess in Cylinder Head (two-valve); wear limit 1.63 mm (0.064 in.)	0.61—1.11	mm (0.024—0.044 in.)
Clearance	Intake and Exhaust Valve Guide-to-Valve Stem Wear Limit (four-valve)	0.15	mm (0.0059 in.)
Clearance	Intake and Exhaust Valves—Maximum Variation for a Pair of Valves (Per Cylinder)	0.3	mm (0.012 in.)
Clearance	Main Bearing Bore Centerline-to-Cylinder Block Top Deck—Distance	337.896—337.972	mm (13.3029—13.3059 in.)
Clearance	Maximum Permissible Height Difference at Nearest Point of Two Adjacent Liners, or Within a Single Liner	0.05	mm (0.002 in.)
Clearance	Piston Pin-to-Bushing—Oil Clearance; wear limit 0.102 mm (0.0040 in.)	0.020—0.056	mm (0.0008—0.0022 in.)
Clearance	Piston Rings 4045DF, TF150 and 6068DF, TF150 No. 1 Compression—End Gap	0.33—0.58	mm (0.013—0.023 in.)
Clearance	Piston Rings 4045TF250 and 6068TF250 No. 2 Compression—End Gap	0.75—1.00	mm (0.030—0.039 in.)
Clearance	Piston-to-Liner Clearance at Bottom of Piston Skirt (Naturally Aspirated Engines)	0.08—0.14	mm (0.003—0.005 in.)
Clearance	Piston-to-Liner Clearance at Bottom of Piston Skirt (Turbocharged Engines)	0.08—0.15	mm (0.003—0.006 in.)
Clearance	Rocker Arm Bore—ID (four-valve); wear limit 20.16 mm (0.794 in.)	20.065—20.115	mm (0.790—0.792 in.)
Clearance	Rocker Arm Bore—ID (two-valve); wear limit 20.17 mm (0.794 in.)	20.07—20.12	mm (0.790—0.792 in.)
Clearance	Rocker Arm Shaft—OD (four-valve); wear limit 19.91 mm (0.784 in.)	19.962—20.038	mm (0.786—0.789 in.)
Clearance	Rocker Arm Shaft—OD (two-valve); wear limit 19.94 mm (0.785 in.)	19.99—20.02	mm (0.787—0.788 in.)
Clearance	Valve Bridge—Pocket-to-Pocket Variation (Maximum)	0.1	mm (0.004 in.)
Clearance	Valve Guide-to-Valve Stem (New) Clearance (two-valve); wear limit 0.15 mm (0.006 in.)	0.05—0.10	mm (0.002—0.004 in.)
Clearance	Valve lift	7/8	turn	RSN nozzle, Tier II certified engines
Clearance	Vibration Damper—Maximum Radial Runout	1.50 mm (0.060 in.)	mm	engine at operating temperature
Clearance	Vibration damper maximum radial runout	1.50	mm	engine at operating temperature
Gap	Magnetic pick-up probe air gap to flywheel face	0.64	mm (0.025 in.)
Gap	Valve Face—Maximum Runout (Intake and Exhaust)	0.038	mm (0.0015 in.)
Other	Air cleaner neck to engine intake overlap	38	mm
Other	Auxiliary gear drive, continuous operation at 2500 rpm	30	kW	continuous
Other	Auxiliary gear drive, intermittent operation at 2500 rpm	37	kW	intermittent
Other	Coolant capacity, 4.5 L engine	8.5	L
Other	Coolant capacity, 6.8 L engine	11.3	L
Other	Crankshaft Journal—OD	77.800—77.826	mm (3.0629—3.0640 in.)
Other	Damper Pulley Inner Ring—Wobble (Maximum)	0.5	mm (0.020 in.)
Other	Damper Pulley Outer Ring—Wobble (Maximum)	1.50	mm (0.060 in.)
Other	Damper—Maximum Radial Runout (Concentricity)	1.50	mm (0.060 in.)	engine at operating temperature
Other	Exhaust Valve Head—OD (four-valve)	35.87—36.13	mm (1.412—1.422 in.)

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

Fluid	Grade	Standard	Ambient	Notes
Coolant	Ethylene glycol base coolant	ASTM D6210		Freeze protection: 40%=-24°C (-12°F); 50%=-37°C (-34°F); 60%=-52°C (-62°F)
Coolant	John Deere COOL-GARD II / COOL-GARD II PG pre-mix	ASTM D6210		Or concentrate in 40—60% mixture with quality water. Do not use less than 40% or greater than 60% concentrate.
Coolant	John Deere COOL-GARD Prediluted Coolant (50% ethylene glycol or 55% propylene glycol)	ASTM D6210 prediluted/concentrate; ASTM D4985 requires initial SCA charge		System 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.
Coolant	John Deere COOL-GARD Prediluted Coolant (preferred); John Deere COOL-GARD Coolant Concentrate 40-60% mixture with quality water	ASTM 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 oil	John Deere ENGINE BREAK-IN OIL	Alternate: 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 oil	John 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 oil	John Deere PLUS-50 (preferred); John Deere TORQ-GARD SUPREME (also recommended)	API CI-4 / CH-4 / CG-4 / CF-4; ACEA E5 / E4 / E3 / E2		Multi-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 oil	SAE 10W-30 (if John Deere Break-In oil not available)	API CE, CD, CC; ACEA E2 or E1		Break-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 oil	SAE 15W-40, SAE 10W-40, SAE 10W-30, SAE 5W-30, SAE 0W-40, SAE 30, SAE 40	John 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, E2		Use 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.
Fuel		EN 590 or ASTM D975		Cetane 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.
Fuel	5% blend (B5)	ASTM D6751, EN 14214, or equivalent		Bio-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.
Fuel	Bio-diesel fuel	ASTM 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.
Fuel	Diesel fuel	EN 590 or ASTM D975; Cetane number 40 minimum (greater than 50 preferred) for Non-Certified, Tier I and Tier 2/Stage II engines		Sulfur 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).
Fuel	Diesel fuel per EN 590 or ASTM D975	EN 590 / ASTM D975		Cetane 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).
Fuel	Grade No. 1-D fuel usable below 5°C (40°F); Grade No. 2-D otherwise	EN 590 or ASTM D975		Cetane 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.
Fuel	Winter grade fuel (No. 1-D in North America)		below 0°C	Use when temperatures fall below 0°C (32°F)
Grease	John Deere SD POLYUREA GREASE (preferred)	NLGI Performance Classification GC-LB; also John Deere HD LITHIUM COMPLEX GREASE, HD WATER RESISTANT GREASE, GREASE-GARD		Consult grease supplier before mixing different types of grease.
Grease	John Deere SD POLYUREA GREASE (preferred); HD MOLY GREASE, HD LITHIUM COMPLEX GREASE, HD WATER RESISTANT GREASE, GREASE-GARD (also recommended)	NLGI Performance Classification GC-LB		Some grease thickener types are not compatible; consult supplier before mixing.
Other	John 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.

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

Procedures

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

Remove nozzle from tester and install in holding fixture.
Remove lift adjusting lock nut.
Loosen pressure adjusting screw lock nut using JDG949 Nozzle Wrench.
Reconnect nozzle to tester with tip pointing downward.
Back out lift adjusting screw two or three turns to prevent bottoming.
Turn pressure adjusting screw in (clockwise) to increase opening pressure or out to decrease.
Remove nozzle and secure in holding fixture; tighten pressure adjusting screw lock nut to 10 N•m (7 lb-ft).
Adjust valve lift: turn lift adjusting screw in until valve ceases to open (conventional nozzle).
Turn lift adjusting screw out 3/4 turn counterclockwise (based on zero lift); 1/8 turn tolerance permissible.
Tighten lift adjusting screw lock nut to 5 N•m (3.5 lb-ft).
Recheck nozzle opening pressure and chatter.

Adjusting Variable Speed (Droop) on Generator Set Engines (Stanadyne Mechanical Injection Pumps Only) adjustment

Warm engine to normal operating temperature.
When necessary, disconnect throttle linkage or cable.
Adjust slow idle and adjust fast idle speed when necessary.
Run engine at fast idle, then apply load until reaching rated speed.
Check power. Adjust with the screw if needed.
Remove load from engine.
Again check and adjust fast idle if the droop screw has been turned.
Repeat procedure until both the engine power and the fast idle speed are correct.
Reinstall throttle linkage if previously removed.

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

Install JT07158 (or FKM10429A) TIME TRAC Kit.
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.
Install magnetic pick-up in flywheel timing hole with 0.64 mm (0.025 in.) air gap; do not stop engine at TDC.
Engine OFF; push ON/CLEAR; select MAG PROBE, set Trig Level to 70%, press ENTER.
Set Offset to 0 degrees and press ENTER.
Start engine, press ENTER; run engine at 1300 rpm, press ENTER to calibrate.
Warm engine to normal operating temperature; check slow and fast idle rpm; adjust as necessary.
Run engine at wide open throttle and load engine down gradually to rated speed rpm.
Record engine speed and timing degrees; compare to Section 06, Group 210 or machine technical manual.
Stop engine; loosen injection pump mounting flange nuts and adjust pump timing.
To advance timing rotate top of pump clockwise (viewed from rear/flywheel end); to retard rotate counterclockwise.
Tighten injection pump mounting flange nuts to 27 N•m (20 lb-ft).
Start engine and recheck dynamic timing; adjust as needed.
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

With engine running, pull governor control lever rearward to slow idle speed position; check speed.
Remove slow idle stop screw cover.
Loosen lock nut and back out bumper spring adjusting screw three turns.
Loosen lock nut and adjust slow idle stop screw to obtain idle 30—50 rpm less than desired slow idle setting.
Turn bumper spring adjusting screw in to increase engine speed a maximum of 30—50 rpm to desired slow idle.
If surging persists, replace bumper spring and adjustment screw.
Recheck fast and slow idle speeds; readjust slow idle if needed.
Check all adjusting screw lock nuts for tightness; install covers.
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

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

Disconnect NEGATIVE battery terminal.
Remove rocker arm cover and crankcase ventilator tube.
Remove plugs from timing/rotation hole and timing pin hole.
Rotate flywheel until No. 1 cylinder is at TDC compression; insert timing pin.
Loosen jam nut on rocker arm adjusting screw.
Turn adjusting screw until feeler gauge slips with slight drag.
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

Disconnect NEGATIVE battery terminal.
Remove rocker arm cover and crankcase ventilator tube.
Remove plugs from engine timing/rotation hole and timing pin hole.
Rotate flywheel until No. 1 cylinder is at TDC compression; insert timing pin.
Loosen jam nut on rocker arm adjusting screw.
Turn adjusting screw until feeler gauge slips with a slight drag.
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

Install JDG1341 Belt Tension Gauge on belt halfway between pulleys.
Loosen cap screws (B) and (C).
Slide alternator or tensioner bracket in slot to remove all excess slack.
Stretch belt by prying outward on alternator front frame or tensioner bracket.
Tighten cap screws (B) and (C).
Run engine for ten minutes and immediately re-check belt tension per used belt specification.
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

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

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

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

Measure Valve Lift diagnostic

⚠ Measure at 0.00 mm clearance and with engine COLD

Tools: JDG1571 or JDE81-4 Timing Pin, Flywheel turning tool, Dial indicator

Remove rocker arm cover.
Set No. 1 piston at TDC compression and install timing pin.
Set rocker arm-to-valve tip clearance to 0.00 mm for the appropriate valves.
Place dial indicator on top of valve spring cap or rotator; set dial to 0.
Remove timing pin and rotate engine one full revolution (360°).
Record maximum dial reading as valve reaches full open.
Compare to specification; if out of spec, inspect entire valve train and camshaft.

Pressure Testing Cooling System diagnostic

⚠ Explosive release of fluids from pressurized cooling system can cause serious burns. Only remove filler cap when cool enough to touch with bare hands.

Tools: D05104ST Tester

Test radiator cap: remove radiator cap and attach to D05104ST Tester.
Pressurize cap to specification. Gauge should hold pressure for 10 seconds within normal range.
If gauge does not hold pressure, replace radiator cap.
Remove the cap from gauge, turn it 180°, and retest cap.
Test cooling system: allow engine to cool, remove radiator cap, fill radiator with coolant to normal operating level.
Connect gauge and adapter to radiator filler neck and pressurize cooling system to radiator cap specification.
With pressure applied, check all cooling system hose connections, radiator, and overall engine for leaks.
If leakage is detected, correct and pressure test again.

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

Common questions

How many kW is the John Deere 6068TF250?

The John Deere 6068TF250 is rated 100 kW standby.

What engine does the John Deere 6068TF250 use?

The John Deere 6068TF250 is powered by the John Deere 6068TF250 engine.

What is the cooling system capacity of the John Deere 6068TF250?

The John Deere 6068TF250 cooling system holds 7.4 liters (2.0 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.

How much oil does the John Deere 6068TF250 take?

The John Deere 6068TF250 has an engine oil capacity of 6.2 liters (6.6 US quarts), per the manufacturer specification sheet.

What is the dry weight of the John Deere 6068TF250?

The John Deere 6068TF250 has a dry weight of 4860 kg (10714 lb).

How big is the fuel tank on the John Deere 6068TF250?

The John Deere 6068TF250 has a 70 liter (18 US gallon) fuel tank.

What voltage does the John Deere 6068TF250 produce?

The John Deere 6068TF250 is offered in 240 V, 208 V, 480 V, 1ph,3ph-phase.

How many cold cranking amps does the John Deere 6068TF250 require?

The John Deere 6068TF250 uses 925 batteryies, 12 V each, 925 CCA, per the manufacturer specification sheet.

What alternator does the John Deere 6068TF250 use?

The John Deere 6068TF250 uses a Mecc Alte ECO 34-2L alternator.

What oil filter fits the John Deere 6068TF250?

The John Deere 6068TF250 uses oil filter part number GM32809.

Troubleshooting

Symptoms & remedies

Symptom	Cause	Remedy
Alternator does not excite	Blown fuse	Replace fuse
Alternator does not excite	Insufficient voltage	Increase speed by 15%
Alternator does not excite	No residual voltage	For an instant apply on the + and – terminals of the electronic regulator a 12 V battery voltage with a 30 ? resistor in series respecting the polarities
After being excited, alternator does not excite	Connections are interrupted	Check connection cables per drawings
Low voltage at no load	Voltage potentiometer out of setting	Reset voltage
Low voltage at no load	Intervention of protection	Check RPM

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full John Deere 6068TF250 troubleshooting guide (102 entries) →

Repair guides

Step-by-step procedures compiled from the John Deere service manual for this model.

Parts

Part #	Description	Qty	System
223673	Filter, oil	1	Oil filter	Amazon eBay $26.99 NAPA $35.41 KuduParts $14.00

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Fuel consumption

Rating	L/h	gal/h
No/full load	6.8	7.9
Prime	6.8	1.8
Standby	1.0	0.26

Available documents

Engine spec — 06-05 John Deere 4045, 6068 (John Deere)Engine spec — 6068TF220 C (John Deere)Engine spec — 6068TF250 B (John Deere)Engine spec — 6068TF250 B S0 R0 (John Deere)Engine spec — 6068TF250 D (John Deere)Engine spec — 6068TF250 D S0 R0 (John Deere)Engine spec — 6068TF250 E (John Deere)Engine spec — 6068TF250 H (John Deere)Engine spec — 6068TF250 H S0 R0 (John Deere)Engine spec — 6068TF250 I (John Deere)Engine spec — 6068TF250 I S0 R0 (John Deere)Engine spec — 6068TF250 indEngine spec — John-Deere-4045-6068-eng (John Deere)Engine spec — dswt89-industrial-engine-selection-guide (John Deere)Engine spec — off highway diesel engine ratings (John Deere)Operator's manual — CTM207 (John Deere)Owner's manual — JD 4045-6068 01FEB02 (John Deere)Owner's manual — TP5853 (John Deere)Owner's manual — TP5853F (John Deere)Parts manual — gm turbo john deere parts (John Deere)Parts manual — tp5386 (John Deere)Parts manual — tp6286Service manual — CTM104 30JUN05 PWT4.5and6.8Base GB (John Deere)Service manual — CTM207 JD 4045 6068 Mechanical Fuel (John Deere)Service manual — Eng SM tp5854 (John Deere)Service manual — John-Deere-4045-Manual (John Deere)

This page was generated from the 26 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.

John Deere 6068TF250 Generator Set

Service parts for the 6068TF250

Oil system

Specifications

Engine

Filters for the John Deere 6068TF250

Same engine, other brands

Maintenance & consumables

Service intervals

Service specifications

Recommended fluids

Procedures

Common questions

Troubleshooting

Symptoms & remedies

Repair guides

Parts

Fuel consumption

Available documents