John Deere 6135 Marine Engine Turbocharger Replacement: What Should You Check First?
Your John Deere 6135 marine engine isn't performing the way it normally does.
Maybe it feels down on power.
Perhaps you're seeing more exhaust smoke than usual, hearing an unfamiliar noise from the turbocharger area, or you've found oil around the intake or exhaust side.
The first thought might be:
“The turbo is bad. I need a new John Deere 6135 turbocharger.”
Maybe.
But before ordering one, there are a few things worth checking.
The John Deere 6135 is a 13.5-litre six-cylinder engine family with several marine configurations. Different ratings and installations mean you shouldn't select a turbocharger simply because a listing says “fits John Deere 6135.”
For other components, visit our John Deere 6135 Marine Engine Parts page.
Which John Deere 6135 Marine Engines Use a Turbocharger?
The John Deere 6135 marine family includes turbocharged engine configurations such as:
6135AFM75
6135AFM85
6135SFM75
6135SFM85
6135HFM85
These engines use turbocharging together with applicable charge-air cooling arrangements to deliver the required marine-engine performance.
But that doesn't mean you should assume every 6135 uses an identical turbocharger.
Engine model, rating, serial number and configuration still matter.
What Is a Verified John Deere 6135 Turbocharger Part Number?
One important confirmed reference is:
RE544926 — John Deere Reman Turbocharger
John Deere lists RE544926 as a Reman turbocharger for marine applications including:
- 6135AFM75
- 6135AFM85
- 6135HFM85
- 6135SFM75
- 6135SFM85
That makes RE544926 a useful reference when sourcing a replacement turbocharger for these engines.
However, we still recommend confirming the complete engine model, engine serial number and existing turbocharger identification before ordering.
A compatibility listing is a starting point.
The engine information is the final check.
Does RE544926 Fit Every John Deere 6135?
No — don't treat it that way.
RE544926 is documented for several 6135 marine applications, but 6135 alone isn't enough information to identify every turbocharger requirement.
If someone sends us:
“Need turbo for John Deere 6135.”
we'd ask for more information.
Ideally:
Engine model: 6135AFM85
Engine serial number: XXXXX
Existing turbo number: XXXXX
Quantity: 1
If you can also send photographs of the existing turbocharger and engine plate, even better.
My John Deere 6135 Has Lost Power. Is the Turbocharger Bad?
Possibly, but don't order a turbocharger based on power loss alone.
A turbocharger problem can reduce boost pressure and engine performance, but several other problems can produce similar symptoms.
These can include:
- Restricted air filter or air intake
- Charge-air leak
- Damaged intake hose
- Aftercooler restriction
- Exhaust restriction
- Fuel-system problem
- Injector problem
- Sensor or control-system fault
- Engine overload
- Turbocharger control problem
- Internal engine condition
So if the engine suddenly feels weak under load, the turbocharger is certainly worth inspecting.
It just shouldn't automatically be blamed.
What Are Common Signs of a Failing 6135 Turbocharger?
Several symptoms can justify a closer inspection.
Loss of Power
If the turbocharger isn't producing the expected boost, the engine may struggle to produce normal power.
This can become especially noticeable under load.
Unusual Turbocharger Noise
A turbocharger normally makes some noise.
A new whining, scraping or unusual mechanical sound deserves attention.
Excessive Exhaust Smoke
Changes in air supply can affect combustion and contribute to abnormal exhaust smoke.
But smoke alone doesn't prove the turbocharger has failed.
Oil Around the Turbocharger
Oil found around the compressor or turbine side should be investigated.
Before condemning the turbo, however, check the lubrication system, oil drain and surrounding connections.
Excessive Shaft Movement
Abnormal shaft movement can indicate internal wear.
Turbocharger shaft condition should be evaluated according to the correct service specifications rather than by guessing from feel alone.
Can a Boost Leak Feel Like a Failed Turbocharger?
Absolutely.
This is a very realistic situation.
The engine loses power.
The operator says:
“Turbo isn't boosting.”
A replacement turbocharger is ordered.
The new turbo goes on.
And the engine still has the same problem.
Why?
Because the turbocharger wasn't the problem.
A damaged hose, loose connection, leaking charge-air joint or another problem between the turbocharger and engine can allow compressed air to escape.
So before replacing an expensive turbocharger, inspect the complete charge-air system.
Can a Dirty Aftercooler Reduce Turbocharger Performance?
It can affect the overall air system and engine performance.
The turbocharger and aftercooler work as parts of the same air-handling system.
John Deere marine 6135 engines use different aftercooling arrangements depending on the model designation.
For example, John Deere identifies the A, S and H designations with different charge-air cooling configurations.
So when investigating low power or abnormal boost performance, don't look only at the turbocharger.
Consider the entire intake and charge-air system.
What Does AFM, SFM or HFM Mean on a John Deere 6135?
These letters provide useful information about the engine configuration.
For the 6135 marine family, John Deere's model designation identifies different air-intake and aftercooling arrangements.
In simplified terms:
A — turbocharged and aftercooled, air-to-engine coolant
S — turbocharged and aftercooled, air-to-seawater
H — turbocharged and aftercooled, air-to-air
That is one reason why the complete designation matters.
6135AFM85 tells you much more than simply 6135.
Can Low Oil Supply Damage a Turbocharger?
Yes.
A turbocharger depends heavily on correct lubrication.
Its rotating assembly operates at extremely high speed.
Problems with oil supply can quickly become turbocharger problems.
If a turbo has failed, we'd want to understand why it failed before fitting the replacement.
Check the relevant lubrication components and oil supply according to the engine service procedure.
Installing a new turbo without addressing an oil-supply problem can damage the replacement.
What About the Turbocharger Oil Return?
The oil needs somewhere to go after lubricating the turbocharger.
A restricted or incorrectly functioning oil return can contribute to oil-related turbocharger problems.
One useful associated John Deere reference is:
R521349 — Engine Turbocharger Oil Return Gasket
John Deere lists R521349 for applicable marine engines including:
6135AFM75
6135AFM85
6135HFM85
6135SFM75
6135SFM85
This doesn't mean the gasket needs replacement every time someone reports a turbo problem.
It simply shows why the turbocharger should be viewed as part of a complete installation rather than as an isolated component.
What Gaskets Are Associated With the John Deere 6135 Turbocharger?
Another useful verified reference is:
R521343 — Engine Turbocharger to Exhaust Elbow Gasket
John Deere lists this gasket for several 6135 marine applications, including:
- 6135AFM75
- 6135AFM85
- 6135HFM85
- 6135SFM75
- 6135SFM85
Another documented reference is:
R518844 — Turbocharger Gasket
This is also listed by John Deere for applicable 6135 marine engines.
When replacing a turbocharger, check which installation gaskets and sealing components are required for the specific engine.
Don't automatically reuse old sealing components simply because they appear intact.
Should I Replace a Turbocharger Just Because It Is Passing Some Oil?
Not automatically.
Oil around the turbocharger can have several possible causes.
Before deciding that the turbo itself has failed, consider:
- Oil supply
- Oil return
- Engine crankcase pressure
- Intake restriction
- Turbocharger wear
- Operating conditions
- Installation condition
The source of the oil needs to be identified.
A turbocharger shouldn't be replaced simply because someone sees oil in the surrounding pipework.
My Turbocharger Failed. Should I Check the Intake System?
Yes.
Before installing the replacement, inspect the air path.
You don't want debris from a previous failure sitting somewhere in the intake system.
Depending on the nature of the failure, inspect applicable:
Air-intake piping
Compressor connections
Charge-air piping
Aftercooler
Intake manifold
If a compressor wheel has suffered physical damage, finding out where the missing material went is important.
Should I Check the Exhaust Side Too?
Yes.
A replacement turbocharger needs to operate in a healthy system.
Inspect the applicable exhaust connections and mounting surfaces.
Look for problems such as:
- Damaged gaskets
- Loose connections
- Cracks
- Exhaust leakage
- Restrictions
- Debris
- Damaged mounting surfaces
Exhaust leaks around the turbine side can also affect turbocharger operation.
Can I Install a Used John Deere 6135 Turbocharger?
A used turbocharger may physically fit, but that doesn't automatically make it a good replacement.
You need to know its:
Correct part number
Previous application
Operating history
Shaft condition
Housing condition
Wheel condition
Lubrication history
A used turbocharger with an unknown history can turn an urgent repair into another repair.
Depending on availability and customer requirements, a new, Reman, OEM-quality or suitable replacement turbocharger may be the better option.
Is RE544926 New or Remanufactured?
RE544926 is a John Deere Reman turbocharger.
That distinction should be clear when requesting or comparing quotations.
Don't compare the price of a Reman turbocharger directly with an unknown aftermarket unit without also comparing:
Condition
Specification
Warranty
Core requirements
Manufacturer
Actual compatibility
Price alone doesn't tell you whether two turbochargers are equivalent.
Should I Replace the Turbocharger Gaskets at the Same Time?
When a turbocharger is removed, check the installation hardware and sealing components required by the service procedure.
Applicable 6135 references include:
| Part NumberDescription | |
| RE544926 | John Deere Reman turbocharger |
| R521343 | Turbocharger-to-exhaust-elbow gasket |
| R521349 | Turbocharger oil-return gasket |
| R518844 | Turbocharger gasket |
These are useful verified references for applicable 6135 applications.
They should still be checked against the exact engine model and serial number before ordering.
John Deere 6135 Turbocharger FAQs
What turbocharger fits a John Deere 6135AFM85?
RE544926 is a John Deere Reman turbocharger listed for the 6135AFM85.
Confirm the complete engine serial number and existing turbocharger before ordering.
Does RE544926 fit the John Deere 6135SFM85?
Yes. John Deere lists 6135SFM85 among the compatible marine applications for RE544926.
Does RE544926 fit the 6135HFM85?
Yes. John Deere also lists 6135HFM85 as an applicable engine for RE544926.
Is RE544926 a marine turbocharger?
Yes.
John Deere specifically states that RE544926 is used only in marine applications.
Can a bad turbocharger cause a John Deere 6135 to lose power?
Yes, a turbocharger problem can contribute to low boost and reduced engine power.
But low power can also result from air leaks, aftercooler problems, fuel-system issues, exhaust restrictions and other engine problems.
Diagnose the cause before replacing the turbo.
Can a bad turbo cause black smoke?
Insufficient air supply can contribute to poor combustion and black smoke.
However, black smoke alone doesn't confirm a turbocharger failure.
Fuel delivery, air restrictions, engine load and other issues should also be investigated.
Should I replace the turbo if it is making noise?
An unusual turbocharger noise deserves inspection, particularly if it is new or accompanied by performance changes.
But identify the source of the noise before ordering a replacement.
Do I need the serial number to order a 6135 turbocharger?
We strongly recommend providing it.
The best information is:
Complete engine model + engine serial number + existing turbocharger number.
That gives us a much stronger basis for identifying the correct replacement.
Related John Deere Marine Engine Pages
For additional engine components and information:
John Deere 6135 Marine Engine Parts
John Deere 6090 Marine Engine Parts
John Deere 6068 Marine Engine Parts
John Deere Marine Engine Parts
John Deere Marine Engine Types & Applications
Marine Spare Parts Catalogue
Need a John Deere 6135 Marine Turbocharger?
Looking for a John Deere 6135 marine engine turbocharger, Reman turbo, turbocharger gasket or related air-system component?
Send us:
Complete engine model
Engine serial number
Existing turbocharger part number
Required quantity
Photographs of the existing turbocharger
Delivery country or port
If you're looking for RE544926, include your complete engine information so the application can be checked before supply.