Home›Engines›John Deere RG6135HF485

John Deere RG6135HF485 Engine

The John Deere RG6135HF485 is a 13.5 L turbocharged engine rated at 1800 rpm. It powers generator sets from Generac and Magnum, including the MMG405, MMG465, MMG405 and MMG405 Super Start. It holds 90.4 L (23.9 gal) of coolant.

Also known as: John Deere RG6135HF485

13.5 L

Displacement

1800 rpm

Rated speed

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Coolant capacity	90.4 L
Displacement	13.5 L
Aspiration	turbocharged
Rated speed	1800 rpm

Generator sets powered by this engine

Shared across brands: Generac, Magnum

Generac MMG405 Generac MMG465 Magnum MMG405 Magnum MMG405 Super Start Magnum MMG465

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

Common problems

OVERSPEED OR UNDERSPEED SHUT DOWN
Cause: Engine speed is above or below 60.0 Hz.
Fix: Disconnect loads and check frequency. Adjust engine speed as needed.
OVERCRANK SHUT DOWN
Cause: Engine will not start.
Fix: Check fuel level, fuel pump operation, air filter for blockage. Refer to engine manual for additional troubleshooting.
LOW OIL PRESSURE SHUT DOWN
Cause: Oil pressure is less than 20 psi (138 kPa).
Fix: Check oil level, inspect for leaks, check oil pressure sender.
LOW FUEL LEVEL SHUT DOWN
Cause: Fuel level is low or fuel tank has leaks.
Fix: Check and refill fuel. Inspect for leaks.
LOW COOLANT LEVEL SHUT DOWN
Cause: Coolant level is low or coolant lines have leaks.
Fix: Check and refill coolant. Inspect for leaks. Check engine oil for contamination.
HIGH COOLANT TEMPERATURE SHUT DOWN
Cause: Coolant temperature is 230°F (110°C) or more.
Fix: Check coolant level, add if necessary. Inspect for leaks. Check radiator shroud and ducting. Adjust water pump belt tension.

Compiled from service & troubleshooting documentation across every generator set that uses the John Deere RG6135HF485.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	paper element		—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Engine oil and oil filter	Change	250 hr		First service — Change after first 100 hours, then every 250 hours. If John Deere PLUS-50 or equivalent is used, every 500 hours.
Oil vapor recirculation system/non-return valve	Check	250 hr
Air intake hoses, connections, and system	Check	500 hr	12 mo
Battery	Inspect	500 hr	12 mo	Service battery
Belt tensioner and belt wear	Check	500 hr	12 mo	At 500 hour/12 month interval, remove belt and check for wear; inspect pulleys and bearings
Coolant pump weep hole foam filter	Check	500 hr	12 mo
Cooling system	Check	500 hr	12 mo
Engine ground connection	Check	500 hr	12 mo
Engine mounts	Check	500 hr	12 mo
Fuel filters/water separator	Replace	500 hr	12 mo	Replace fuel filters/clean water separator
Generator drive plate torque	Check	500 hr	12 mo	See page 45
Leveling jack(s)	Lubricate	500 hr	12 mo
Oil vapor recirculation filter	Replace	500 hr	12 mo
Thermostats	Test	500 hr	12 mo
Air cleaner elements	Replace	2000 hr	24 mo
Alternator and fan belts	Replace	2000 hr	24 mo
Coolant	Check	2000 hr	24 mo	Add coolant
Electrical wiring and connections	Check	2000 hr	24 mo
Fuel system	Drain	2000 hr	24 mo	Bleed fuel system
Fuses	Check	2000 hr	24 mo

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
Other	Fine voltage adjustment window (V Detect)	45	seconds
Other	Fuel level low fuel shutdown setpoint	5	%
Other	Fuel level low fuel warning setpoint	15	%
Pressure	Air filter restriction indicator - replace element	20	in. H2O
Pressure	Air filter restriction indicator - replace primary air cleaner	25	in. H2O
Pressure	Engine oil pressure, low oil pressure shut down	less than 20	psi (138 kPa)
Pressure	Engine oil pressure, normal operating	35-80	psi (241-552 kPa)	engine running
Pressure	Engine oil pressure, verify within 5 seconds of start	5	psi (34 kPa)	within 5 seconds of start
Speed	Generator frequency, no load	60.0	Hz	no load
Speed	Operating speed	1800	rpm
Temperature	Coolant temperature minimum display	100	°F (38°C)
Temperature	Maximum water/coolant temperature shut down	230	°F (110°C)
Temperature	Viscous fan clutch temperature range	170-200	°F (77-93°C)
Torque	Generator drive plate bolts	33	ft-lb (45 Nm)
Torque	Shorting (link) board hardware	25	ft-lbs
Torque	Trailer wheel lug nuts, first pass	20-25	ft-lbs (27-33 Nm)
Torque	Trailer wheel lug nuts, second pass	50-60	ft-lbs (67-81 Nm)
Torque	Trailer wheel lug nuts, third pass	90-120	ft-lbs (122-162 Nm)
Voltage	Battery voltage, normal reading on 12 volt systems	13-14	V	engine running
Voltage	Battery voltage, normal reading on 24 volt systems	24-26	V	engine running
Voltage	Voltage regulation	+/- 1	%

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	Capacity	Notes
Engine oil	John Deere PLUS-50 or equivalent				Consult the engine operation and maintenance manual for the proper grade of oil, including special operating conditions. If John Deere PLUS-50 or equivalent is used, oil can be changed every 500 hours.
Grease	High quality grease made specifically for lubrication of wheel bearings				Trailer wheel bearings; minimum lubrication every 12 months or 12,000 miles (19,312 km)

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

Fault codes

Code	Name	Meaning	Severity	Action
AnInIOM Sd	AnInIOM Sd	Shutdown alarm configurable on the input of IG-IOM/IGS-PTM.	Shutdown
AnInIOM Wrn	AnInIOM Wrn	Warning alarm configurable on the input of IG-IOM/IGS-PTM.	Warning
Battery Flat	Battery Flat (low battery)	If the controller switches off during starting sequence due to bad battery condition, it doesn't try to start again and activates this protection.	Shutdown
Binary Input	Binary Input	Configurable warning/shutdown alarms on the inputs of IL-NT.
ChrgAlternFail	ChrgAlternFail	Failure of the alternator to charge the battery.	Warning
EmergencyStop	EmergencyStop	If the input Emergency Stop is opened or the red E-Stop button is pushed, shutdown is immediately activated.	Shutdown
Engine Temp Sd	Engine Temp Sd	Water temperature is greater than Sd Water Temp setpoint.	Shutdown
Engine Temp Wrn	Engine Temp Wrn	Water temperature is greater than Wrn Water Temp setpoint.	Warning
Fgen<, >	Fgen<, >	The generator frequency is out of limits given by Gen >f and Gen <f setpoints.	Shutdown
Fuel Level Sd	Fuel Level Sd	Fuel level is smaller than Sd Fuel Level setpoint (5%).	Shutdown
Fuel Level Wrn	Fuel Level Wrn	Fuel level is smaller than Wrn Fuel Level setpoint (15%).	Warning
GCB fail	GCB fail	Failure of the generator circuit breaker.	Shutdown
Igen unbl	Igen unbl	The generator current is unbalanced.	Shutdown
Low BackupBatt	Low BackupBatt	RTC backup battery is flat (low).	Warning
Oil Press Sd	Oil Press Sd	Oil pressure is smaller than Oil Press Sd setpoint.	Shutdown
Oil Press Wrn	Oil Press Wrn	Oil pressure is smaller than Oil Press Wrn setpoint.	Warning
Overload	Overload	The load is greater than the value given by Overload setpoint.	Shutdown
Overspeed	Overspeed	The protection comes active if the speed is greater than Overspeed setpoint.	Shutdown
ParamFail	ParamFail	Wrong checksum of parameters. Happens typically after downloading new firmware or changing of the parameter. The controller stays in INIT mode.		Check all parameters, write at least one new parameter.
PickupFault	PickupFault	Failure of the magnetic pick-up sensor for speed measurement.	Shutdown
Sd IOM fail	Sd IOM fail	IOM/IGS-PTM module.	Shutdown
SprinkIActive	SprinkIActive	The protection is active if the output Sprinkler is closed.	Warning
Start failed	Start failed	Unit did not start.	Shutdown
Stop fail	Stop fail	Unit did not stop.	Shutdown
Ubat	Ubat	Battery voltage is out of limits given by Batt Undervolt setpoints.	Warning
Underspeed	Underspeed	During starting, when the RPM reaches Starting RPM setpoint the starter switches off and speed can drop under Start RPM again; underspeed protection becomes active. Evaluation starts 5 seconds after start up.	Shutdown
Vgen unbal	Vgen unbal	The generator voltage is unbalanced more than the value of Volt unbal setpoint.	Shutdown
Vgen<, >	Vgen<, >	The generator voltage is out of limits given by Gen <V and Gen >V setpoints.	Shutdown
Wrn ECU Alarm	Wrn ECU Alarm	ECU alarm list is not empty.	Warning
Wrn RA15 fail	Wrn RA15 fail	Warning alarm in case of lost connection to IGL=RA15 module.	Warning
WrnMaintenance	WrnMaintenance	The period for servicing is set by the WrnMaintenance setpoint. The protection comes active if the running hours of the engine reach this value (250 hours).	Warning

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

Procedures

Adjusting the Display Back Lighting adjustment

Press and hold Enter.
Press the up or down buttons on the Diagnostics keypad to increase or decrease brightness.
Release the Enter button when the desired brightness is attained.

Changing Output Voltage adjustment

⚠ NEVER ATTEMPT TO CHANGE THE VOLTAGE WHILE THE ENGINE IS RUNNING. LETHAL VOLTAGE MAY BE PRESENT AT THE CONNECTION LUGS ON THE SHORTING (LINK) BOARD.

Tools: Wrench, Torque wrench

Shut the generator down and set main circuit breaker and control power switch to OFF.
Remove all 1/2 in. nuts holding the shorting (link) board.
Move the board to the lower position for 480/277V 3Ø or the upper position for 208/120V 3Ø.
Replace all hardware and tighten to 25 ft-lbs of torque.
Reinstall the reconnect box door and start the generator per the Pre-Start Check List.

Resetting of the Time to Service Reminder adjustment

With the unit shut down, power up the controller with the Control On/Off toggle switch.
Press Page Select, move the cursor down to Engine Protect and press Enter.
Press Enter; the current run time in hours appears under WrnMaintenance.
Press the up arrow and reset the current run time hour setting to 250.
Press Enter to save the current run time hour setting.
Move the CONTROL ON/I toggle switch to the CONTROL OFF/O position.

Checking Generator Drive Plate Torque maintenance

Tools: Torque wrench

Disconnect the engine starting battery.
Remove the generator fan guard.
Torque each of the drive plate bolts to 33 ft-lb (45 Nm).
Reinstall the generator fan guard and reconnect the battery.

Trailer Wheel Bearings maintenance

Tools: Grease gun

Remove the small rubber plug on the grease cap.
Attach a standard grease gun fitting to the grease zerk fitting.
Pump grease into the fitting until new grease is visible around the nozzle.
Wipe any excess grease from the hub and replace the rubber plug.

AUTO (Remote) Starting of the Generator operation

Perform a manual start of the generator at least once to verify correct operation.
Press the AUTO button; LCD window highlights AUTO in the upper left corner.
Close the main circuit breaker (set to ON/I).
Secure the generator by closing and locking all access doors.
The generator is now ready for remote starting.

Auto Exercise Timer operation

⚠ The controller must be in AUTO mode to run at the programmed time.

Press the PAGE SELECT button until Password appears at the top of the screen.
Press the down arrow to select Date/Time and press ENTER.
Press the down arrow to select Timer1 Repeat and press ENTER; choose the day(s) and press ENTER.
Select Timer1 ON Time and press ENTER; adjust the desired start time.
Select Timer1Duration and press ENTER; set the run duration.
Press PAGE SELECT three times to return to the main menu.
Press the AUTO button to switch modes to automatic.

Auxiliary Fuel Tank Option operation

Shut down the unit and check that the internal tank fuel level is above five percent.
Attach the auxiliary fuel tank fuel lines to the AUXILIARY FUEL INLET and AUXILIARY FUEL OUTLET fittings.
Open the AUXILIARY FUEL INLET and AUXILIARY FUEL OUTLET valves inside the right front door.

Fuel Transfer Pump Option operation

Shut down the unit (not required if external bulk supply is already connected).
Attach the external bulk fuel supply to the FUEL TRANSFER INLET fitting.
Turn on the fuel transfer switch.

Manual Starting of the Generator operation

⚠ CARBON MONOXIDE: USING A GENERATOR INDOORS CAN KILL YOU IN MINUTES!

Move the control ON/OFF toggle switch to the CONTROL ON/I position.
LCD window indicates MAN mode and Ready; Ready/Manual LED is lit.
Press the green ENGINE START button.
Prestart (Preheat) screen is displayed with a countdown from 20 seconds to zero.
Starting screen is displayed; the engine cranks and starts running.
Running screen displays.
LCD toggles between Generator Display Screen and Engine Display Screen.
If engine does not start, controller pauses 15 seconds and makes two more attempts (three total).
If no start after three cycles, LCD shows SD Start Fail; wait two minutes and press FAULT RESET.
Engine speeds up to a constant 1800 rpm.
Check for excessive noise or vibration and coolant, oil or fuel leaks before applying loads.
Check AC output voltage; fine adjust with the fine voltage adjustment screw if needed.
Check frequency reads approximately 60 Hz with no loads.
Switch main circuit breaker ON, then convenience outlet breakers as needed.

Shutting Down the Generator operation

⚠ If the unit does not shut down within 15 seconds, a Stop Fail alarm is displayed.

Open all circuit breakers to remove loads from the generator.
Let the engine run approximately five minutes to allow it to cool down.
Push the red ENGINE STOP button; a 15 second Stop Value timer starts.
Move the CONTROL ON/OFF toggle switch to the CONTROL OFF/O position.

Towing the Trailer operation

Use the jack to raise or lower the trailer onto the hitch; lock the hitch coupling.
Attach the safety chains or cables to the vehicle and raise the jack foot completely.
Connect trailer wiring; check stop and signal lights.
Make sure all doors are properly latched.
Check trailer tire inflation.
Check the wheel lugs and tighten or replace any loose or missing.
Limit highway towing speed to 45 mph (72 km/h).

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

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
		Cam lock connections	L1 - Black, L2 - Red, L3 - Blue, N (Neutral) - White, G (Ground) - Green	Series 16 taper nose 400A, 600V cam locks; make all connections to one side only
120	3	Low Delta	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
208/120	3	Link board attached in 208 VOLT 3Ø position (upper position)	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Shorting (link) board upper position
208/120	3	Low Wye	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
240/120	1	Low Zig Zag	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
240/120	3	High Delta	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
480/240	1	High Zig Zag	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
480/277	3	High Wye	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Dedicated 12 lead generators option
480/277	3	Link board attached in 480 VOLT 3Ø position (lower position)	T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12	Shorting (link) board lower position

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

RE531195 FridayParts $38.50 RE518339 FridayParts $108.70 RE531334 FridayParts $108.70 RE543187 FridayParts $239.99 SE501270 Amazon eBay $310.00 FridayParts $239.99

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

Common questions

What is the displacement of the John Deere RG6135HF485?

The John Deere RG6135HF485 has a displacement of 13.5 liters.

Which generators use the John Deere RG6135HF485 engine?

The John Deere RG6135HF485 powers 5 generator set(s), including Generac MMG405, Generac MMG465, Magnum MMG405, Magnum MMG405 Super Start, Magnum MMG465.

What is a common problem with the John Deere RG6135HF485 engine?

A commonly reported issue on generators using the John Deere RG6135HF485 is: OVERSPEED OR UNDERSPEED SHUT DOWN. Cause: Engine speed is above or below 60.0 Hz.. Fix: Disconnect loads and check frequency. Adjust engine speed as needed..