DD Platform Heavy Duty Cylinder Kit Inspection Guideddcsn-ddc.freightliner.com/cps/rde/xbcr/ddcsn/DDC-SVC-MAN-0199.pdf · 1 DD Platform Heavy Duty Cylinder Kit Inspection ... connecting

DDC-SVC-MAN-0199

DD Platform Heavy Duty Cylinder KitInspection Guide

Specifications are subject to change without notice. Detroit Diesel Corporation is registered to ISO 9001:2001.Copyright Detroit Diesel Corporation. All rights reserved. Detroit Diesel Corporation is a Daimler company.Printed in U.S.A.

Table of Contents

1 DD Platform Heavy Duty Cylinder Kit Inspection Guide................................................................................................... 32 Warranty.................................................................................................................................................................................. 4

2.1 Warranty.......................................................................................................................................................................... 43 Cylinder Kit Overview............................................................................................................................................................ 5

3.1 Cylinder Block and Liner................................................................................................................................................ 53.2 Piston and Connecting Rod............................................................................................................................................. 6

4 Normal Wear......................................................................................................................................................................... 104.1 Normal Wear................................................................................................................................................................. 104.2 Piston............................................................................................................................................................................. 104.3 Piston Rings................................................................................................................................................................... 114.4 Piston Pin....................................................................................................................................................................... 134.5 Connecting Rod............................................................................................................................................................. 144.6 Cylinder Liner............................................................................................................................................................... 15

5 Dust Out................................................................................................................................................................................. 195.1 Dust Out........................................................................................................................................................................ 195.2 Cylinder Liner............................................................................................................................................................... 195.3 Piston and Piston Rings................................................................................................................................................. 205.4 Piston Pin....................................................................................................................................................................... 225.5 Repair Strategy.............................................................................................................................................................. 26

6 Scuffing................................................................................................................................................................................... 286.1 Scuffing......................................................................................................................................................................... 286.2 Thrust and Anti-Thrust Scuffing................................................................................................................................... 286.3 Repair Strategy.............................................................................................................................................................. 296.4 360 Degree Scuffing...................................................................................................................................................... 306.5 Repair Strategy.............................................................................................................................................................. 336.6 Broken Piston Ring Scuff.............................................................................................................................................. 336.7 Repair Strategy.............................................................................................................................................................. 356.8 Bent Connecting Rod Scuff........................................................................................................................................... 356.9 Repair Strategy.............................................................................................................................................................. 37

7 Cylinder Kit Wear Out......................................................................................................................................................... 397.1 Cylinder Kit Wear Out.................................................................................................................................................. 397.2 Liner.............................................................................................................................................................................. 397.3 Piston and Rings............................................................................................................................................................ 407.4 Repair Strategy.............................................................................................................................................................. 42

8 Cracked Piston and Impact Damage................................................................................................................................... 438.1 Cracked Piston and Impact Damage............................................................................................................................. 438.2 Repair Strategy.............................................................................................................................................................. 46

9 Piston Dome Separation........................................................................................................................................................ 489.1 Piston Dome Separation................................................................................................................................................ 489.2 Repair Strategy.............................................................................................................................................................. 49

10 Piston Pin Failure................................................................................................................................................................ 5010.1 Piston Pin Failure........................................................................................................................................................ 5010.2 Repair Strategy............................................................................................................................................................ 51

11 Upper Liner O-ring Failure................................................................................................................................................ 5311.1 Upper Liner O-ring Failure......................................................................................................................................... 5311.2 Repair Strategy............................................................................................................................................................ 54

12 Liner Cavitation................................................................................................................................................................... 5612.1 Liner Cavitation........................................................................................................................................................... 5612.2 Repair Strategy............................................................................................................................................................ 57

13 Vertical Failure vs. Horizontal Failure............................................................................................................................. 5813.1 Vertical Failure vs. Horizontal Failure........................................................................................................................ 58

Table of Contents

2 All information subject to change without notice.Copyright 2017 DETROIT DIESEL CORPORATIONDDC-SVC-MAN-0199

1 DD Platform Heavy Duty Cylinder Kit Inspection Guide

The purpose of this guide is to provide detailed inspection instructions for the components that make up a cylinder kit on aDD Platform heavy duty engine. These components include:

Piston Piston Rings Piston Pin and Retainers Piston Cooling Nozzle Connecting Rod Cylinder Liner

This is an educational resource guide to enhance knowledge of cylinder kit wear and defects. This is not step-by-steptroubleshooting. There are many illustrations identifying normal wear and failures associated with cylinder kit components.

The vehicle may enter the shop with any of the following complaints:

High Oil Consumption Excessive Crankcase Pressure Coolant in the Oil Oil in the Coolant Misfire or Misfire Fault Codes Excessive Smoke Engine Locked Up or Seized Noisy or Knocking Low Power High Wear Metals in an Oil Analysis

Identifying the root cause or primary failed part (PFP) is necessary for determining a proper repair strategy, preventingadditional downtime, and deciding responsibility for the failure. The cylinder kit is a system, with several parts workingtogether. Often times, a failure of one component can affect others within the cylinder kit. To determine the root cause of afailure, all parts of the cylinder kit must be examined. Other parts of the engine and vehicle may also need to be inspected.

This information applies to all DD13, DD15 and DD16 on-highway engines.

The Cylinder Kit Inspection Guide is separated into 12 sections.

Warranty Cylinder Kit Overview Normal Wear Dust Out Scuffing Cylinder Kit Wear Out Cracked Piston and Impact Damage Piston Dome Separation Piston Pin Failure Upper Liner O-ring Failure Liner Cavitation Vertical vs. Horizontal Failure

DD Platform Heavy Duty Cylinder Kit Inspection Guide

All information subject to change without notice. 3DDC-SVC-MAN-0199Copyright 2017 DETROIT DIESEL CORPORATION

2 Warranty

2.1 WarrantyDetroit covers repairs resulting from defects in material or manufacturer workmanship of a Detroit product. Determining theroot cause of failure and primary failed part (PFP) is essential in determining the warranty eligibility.

NOTE: Extended Service Coverages (ESC) do NOT cover original or replacement parts that fail as a result ofwear out.

There are several factors that should be considered when determining the PFP and its failure mode.

These factors include:

1. Workmanshipa. Refer to the Warranty Manual for how to proceed in repairs with a failure that is a result of improper

workmanship by a service outlet.2. Contaminated fluids. Examples include, but are not limited to:

a. Contamination as a result of the incorrect fluid being added to the unit. This can include, but is not limited to: Diesel Exhaust Fluid (DEF) in the fuel or fuel in the DEF. Fuel, lubricating oil, or coolant being used outside of the specifications listed in the EPA07/EPA10/GHG14

DD Platform Operators Manual or GHG17 DD Platform Operators Manual.3. Operator-induced failures, abuse, negligence or certain modifications. Examples include, but are not limited to:

Operator-induced engine overspeed. Misapplication, misuse, or storage damage. Failing to follow the correct maintenance schedule. Failure due to a modification exceeding Detroit specifications.

4. Accidents or acts of nature. Examples include, but are not limited to: Flood damage Hurricane damage Lightning damage Vehicular accidentsThe examples above are some examples of situations that would exclude the failure from warranty eligibility.If the failure is identified to be eligible for warranty, the unit should be restored to operating condition by repairing orreplacing only the defective or damaged parts that are necessary, according to the terms of the appropriate warrantystatement. Other parts removed in the repair process will be reinstalled as is, unless the user authorizes the additionalexpense. The intent of a warranty repair is to repair or replace the warranted parts and restore the rest of the engine toits operating condition prior to the warrantable failure, not to restore the engine to like new condition.

2 Warranty


3 Cylinder Kit Overview

3.1 Cylinder Block and LinerThe cylinder liners on a heavy duty DD engine feature a "bottom stop" design, meaning the liners are installed with a lowercollar into the cylinder block. The lower area of the cylinder block is referred to as the balcony. Each cylinder liner has oneupper sealing ring and one lower sealing ring. A removable Carbon Scraper Ring (CSR) was added for GHG14 engines andis incorporated into a recessed area on top of the inner diameter of the liner. The CSR prevents excess carbon build-up on thecylinder liner and piston. This results in consistent oil consumption over the life of the engine.

1. Main Bearing and Crankshaft Bore2. Main Oil Gallery3. Cooling Jacket4. Upper Liner Bore

5. Liner Seat (Balcony)6. Secondary Oil Gallery7. Bay to Bay Breather Passage

Figure 1. Cylinder Block Cutaway (From the Rear)



1. Cylinder Liner2. Head Gasket Compression Seal Surface3. Upper Sealing Ring4. Upper Cooling Jacket

5. Lower Cooling Jacket6. Lower Collar / Balcony Area7. Lower Sealing Ring and Bottom Stop8. Lower Flange

Figure 2. Cylinder Block and Cylinder Liner

1. Lower Liner O-ring Area2. Lower Ring Reversal3. Piston Ring Travel

4. Upper Ring Reversal5. Upper Liner O-ring Area6. Carbon Scraper Ring (CSR) Location

Figure 3. Cylinder Liner



3.2 Piston and Connecting RodThe pistons used in DD Platform heavy duty engines are constructed from a high alloy steel. The piston starts as two piecesand is then welded together using a dual-friction process to form a single unit. This design is very strong and allows forhigher peak cylinder pressures. An anti-friction manganese phosphate coating is applied to the piston pin bore areas and agraphite coating is applied to the piston skirts.

There are three piston rings per piston; the top ring (fire ring), second ring (compression ring), and an oil control ringassembly. The oil control ring assembly consists of two parts. The first part is the oil control ring body, which has twoscraper rails that contact the cylinder liner. The second part is the coil spring, which provides uniform tension to keep thebody of the oil control ring against the cylinder liner. The piston is secured to the connecting rod using a steel piston pin andtwo retaining clips. This allows free movement of the piston assembly during the up and down stroke of the piston andconnecting rod. There is an oil gallery in the piston below the piston dome that cools the piston and provides lubrication tothe oil control ring assembly, piston pin, connecting rod bushing, and the piston skirts. This gallery is supplied with oil fromthe piston cooling nozzle while the piston is at Bottom-Dead-Center (BDC) in its stroke.

The connecting rod is forged from high strength steel and uses a cracked design for the joint from the connecting rod to theconnecting rod bearing cap. This cracked design creates more surface area and increases the strength of the joint. A bushingis pressed into the small end of the connecting rod to support the piston pin. This bushing is not serviced separately from theconnecting rod assembly.

1. Thrust Side of Piston2. Oil Control Ring Assembly3. Second (Compression) Ring

4. Ring Travel Area / Liner Hone5. Top (Fire) Ring6. Anti-Thrust Side of Piston

Figure 4. Piston and Connecting Rod (From Front of Engine)



1. Connecting Rod Bolt (2 qty.)2. Connecting Rod Bushing (Not Serviced Separately)3. Retaining Ring (2 qty.)4. Piston Pin5. Piston

6. Oil Control Ring Assembly7. Compression Ring8. Fire Ring9. Connecting Rod

Figure 5. Piston and Connecting Rod

1. Piston Skirt2. Cover Plate (No Longer Used)3. Piston Pin4. Retaining Clip5. Piston Pin Bore6. Oil Control Ring Assembly7. Compression Ring

8. Fire Ring9. Cooling Gallery

10. Combustion Bowl11. Piston Dome12. Top Land13. Second Land

Figure 6. Piston Assembly



1. Coil Spring Area2. Peaked Oil Scraper Rails

3. Oiling Hole

Figure 7. Oil Control Ring Body

1. Coil Spring 2. Tension WireFigure 8. Oil Control Ring Coil Spring



4 Normal Wear

4.1 Normal WearMoving engine components experience wear during normal operation. The degree of wear will depend on the operatingconditions and operating environment. Much of the wear that is seen in an engine is considered normal, unless there is acondition that leads to additional clearances or visible damage. This section will show examples of normal wear for cylinderkit components. Parts that exhibit normal wear should not be replaced, as no failure is present.

4.2 PistonNormal wear on a piston includes some wear of the anti-friction coating on the piston skirts and piston pin bore areas. Therewill be no scuffing on the piston skirts or ring lands. The piston dome will show no impact damage. The piston rings willmove freely in their respective grooves and there will be minimal carbon build-up on the ring lands and piston dome.

1. Normal Carbon Deposits 2. No Impact DamageFigure 9. Piston Dome Normal Wear

4 Normal Wear


1. Normal Carbon Deposits on Ring Lands 2. No Scuffing or DamageFigure 10. Piston Showing Normal Deposits and No Damage

1. Normal Anti-Friction Coating Wear 2. Normal Light Score MarksFigure 11. Piston Skirt Showing Normal Wear



4.3 Piston RingsThe top (fire) ring will have a dull silver appearance when normally worn. The second (compression) ring is tapered and willwear from the bottom up. The scraper rails on the oil control ring body will be present and not wore down. The scrapers arepeaked when new. All rings will be completely intact with good tension. It should be noted that ring wear will always beheaviest adjacent to the gap area due to ring tension.

1. Rings are Intact and Free in the Ring GroovesFigure 12. Normally Worn Piston Rings

4 Normal Wear


1. Scraper Rails are Present and Not Wore Down2. Compression Ring Normal Wear

3. Fire Ring Dull Silver Appearance

Figure 13. Normal Wear Piston Rings

4.4 Piston PinA piston pin with normal wear will have an even and shiny appearance across the entire surface. There can be oil stainingfrom normal use. There may be some cloudiness at the piston pin bore area from normal wear. The cloudiness occurs due toabrasives in the lubricating oil. The pin will show only minor scoring and the retainers will be intact.



1. Light Scoring 2. Some CloudinessFigure 14. Normal Wear Piston Pin

4.5 Connecting RodThe connecting rod should be free of bends at the beam and show no impact damage. The piston pin bushing may show lightpolishing, staining, and scoring that cannot be felt with a fingernail. The connecting rod bearing shell surface on the rod andbearing cap should be smooth and show no material transfer. The piston pin oiling holes should also be open and clear of anydebris.

4 Normal Wear


1. Staining 2. PolishingFigure 15. Connecting Rod Bushing Showing Normal Wear

1. No Bearing Shell Material TransferFigure 16. Connecting Rod Bearing Shell Surface



4.6 Cylinder LinerA cylinder liner with normal wear will have clearly visible cross-hatch all the way around the ring travel area (360 degrees).There may be some blemishes, cloudy spots, or light score marks that cannot be caught with a fingernail. The top 20 mm(0.80 in) of the ring travel area will typically appear cloudy. Carbon build-up above the upper ring reversal area will bepresent if the liner does not use a carbon scraper ring. The carbon scraper ring helps to prevent carbon raking (verticalstreaks). Carbon raking, by itself, is not a failure.

1. Shadow Marking / Discoloration2. Cloudy Appearance at Upper Ring Reversal

3. Carbon Above Upper Ring Reversal (Without CarbonScraper Ring)

Figure 17. Cylinder Liner Showing Normal Wear

4 Normal Wear


1. Visible Crosshatch / Hone2. Cloudy Appearance at Upper Ring Reversal

3. Carbon Above Upper Ring Reversal (Without CarbonScraper Ring)


1. Staining / Discoloration2. Light Vertical Marks

3. Cloudy / Discoloration




1. Light Polishing 2. Vertical Streaking / Carbon RakingFigure 20. Cylinder Liner Showing Normal Wear

1. Light Polishing 2. White Mark / BlemishFigure 21. Cylinder Liner Showing Normal Wear

4 Normal Wear


5 Dust Out

5.1 Dust OutDust out is a condition that occurs when dirt is able to enter the air intake system and the combustion chambers. The dirtcontaminates cylinder kit lubrication and can rapidly accelerate wear for the cylinder liner bores, piston pins and piston pinbores. This wear leads to abnormally high oil consumption and possible aftertreatment failure. The effects of dust out willtypically be seen in all cylinders since a leak in the air system is generally a systematic problem. The wear may not be exactlythe same on every cylinder, but the signs should still be evident. Any oil lubricated surface could show signs of abrasivescoring including the main and connecting rod bearings. The evidence of abrasion and excessive wear on lubricatedcomponents is the major indicator of a dust out condition. In addition to the visible wear, the engine lubricating oil may alsofeel gritty from dirt particles.

5.2 Cylinder LinerThe cylinder liner will show heavy wear in the ring reversal areas on an engine that has experienced dust out. There may evenbe a noticeable step in the liner. The cross-hatch hone pattern will be almost non-existent and the liner may show verticalscoring from abrasive dirt particles.

1. Wear Step at Lower Ring Reversal2. Wear Step at Upper Ring Reversal

3. Missing Crosshatch / Vertical Scoring

Figure 22. Dusted Liner



1. No Crosshatch / Hone 2. Vertical ScoringFigure 23. Dusted Liner

5.3 Piston and Piston RingsHeavy carbon build-up on the piston dome and top ring land will be typical of an engine that has experienced dirt ingestion(dust out). This carbon build-up is caused by excessive amounts of oil being burned in the combustion chamber. The oilcontrol ring body has two scraper rails that may show excessive wear when the cylinder is subjected to dirt ingestion. Thiscondition is referred to as "flattened or plateaued scrapers". The amount of wear depends on the amount of dirt, type of dirt,and run time.

5 Dust Out


1. Abnormal Carbon DepositsFigure 24. Abnormal Carbon Deposits on Piston Dome

1. Scraper Rails Wore Down (Plateaued) 2. Excessive Carbon DepositsFigure 25. Oil Control Ring Wear and Carbon Deposits



1. Extreme Wear on Oil Scraper Rails (Plateaued)Figure 26. Oil Control Ring Excessive Wear from Dirt Ingestion

1. Oil Control Ring Extreme Wear (Scraper RailsCompletely Worn)

2. Excessive Carbon Deposits

Figure 27. Dusted Oil Control Ring

5 Dust Out


5.4 Piston PinThe piston pin is lubricated by engine oil. If dirt is allowed to enter the cylinders, it can also enter the oiling system. Any oillubricated component can then be subjected to accelerated wear due to the abrasive properties of dirt. A piston pin that hasbeen lubricated with dirty oil will have a very cloudy appearance at the piston pin bore areas. The manganese phosphatecoating on the piston pin bore will match the wear on the piston pin due to abrasion.

1. Heavy Clouding / AbrasionFigure 28. Piston Pin with Abrasive Wear from Dust Out



1. Abrasive WearFigure 29. Piston Pin Bore with Abrasive Wear to Manganese Phosphate Coating

1. Dirt AccumulationFigure 30. Dirt in Charge Air Cooler Piping

5 Dust Out


1. Evidence of DirtFigure 31. Dirt in Charge Air Cooler

1. Dirt ParticlesFigure 32. Dirt Particles in Charge Air Cooler



1. Dirt AccumulationFigure 33. Dirt in Air Filter Housing

1. Dirt in Turbocharger Shaft 2. Abrasive Wear to Compressor WheelFigure 34. Signs of Dirt Ingestion in Turbocharger

5 Dust Out


5.5 Repair StrategyThe following is a recommended repair strategy when a dust out condition has been identified. The primary failed part(PFP) / breach in the air system must be found and corrected to prevent future downtime and make an accurate repair.

1. Determine the cause of the dust out. Possible causes: Leaking air filter housing or inlet to turbocharger Leaking air compressor inlet hose or pipe Torn or damaged air filter Leaking charge air / boost connections Leaking charge air cooler Leaking joints at the cold boost pipe or intake manifold

2. The following components must be cleaned per the appropriate manuals: Air filter housing and tubing Charge Air Cooler (CAC)

3. Replace the following components: All six complete cylinder kits (pistons assemblies, liners, connecting rods) All main and connecting rod bearing shells Oil pump Engine lubricating oil and oil filter Turbocharger Oil cooler Air compressor Charge air boots Supporting gaskets and seals



6 Scuffing

6.1 ScuffingCylinder kits operate in high temperatures, high pressures, and high unit loads. Therefore, pistons, piston rings, and cylinderliners are sensitive to problems with the Air-Fuel-Ratio (AFR), lack of adequate lubrication, and cylinder wall cooling.Scuffing is defined as a slight transfer of metal from one surface to another due to a lack of sufficient lubrication or clearancefrom over-temperature events. If allowed to continue, galling will occur. Galling is a high transfer of metal. There are severaltypes of cylinder kit scuffing described in detail below.

6.2 Thrust and Anti-Thrust ScuffingAs a reminder, the thrust side of the piston / liner is on the exhaust side (valve relief side). The anti-thrust side of the piston /liner is the intake side (no valve relief). A scuff that occurs on the thrust side is considered a "thrust scuff". A scuff on theanti-thrust side is considered an "anti-thrust scuff". There is more load on the thrust side of the piston, so scuffing in this areatends to be more common. The cylinder kit can also scuff on both sides; this is referred to as a thrust / anti-thrust scuff. Manytimes, a scuffed cylinder kit will lead to a horizontal crack at the lower balcony area of the cylinder liner where the liner wallis the thinnest. Coolant will then be allowed to enter the oil sump and contaminate the engine lubrication system. Thelubricity properties of water and coolant are very poor. Therefore, when coolant or water is found in the engine lubricatingoil, all main and connecting rod bearing shells must be replaced and the crankshaft journals must be inspected for damage.

See illustrations below for examples of thrust and anti / thrust scuffing.

1. Scuffing on Thrust SideFigure 35. Liner with a Thrust Scuff

6 Scuffing


1. Scuffed Ring Land and SkirtFigure 36. Piston with a Thrust Scuff

1. Horizontal CrackFigure 37. Liner Crack Due to Cylinder Scuffing



6.3 Repair StrategyThe following is a recommended repair strategy when a thrust or anti-thrust scuff condition has been identified. The primaryfailed part (PFP) must be established to prevent future downtime and make an accurate repair. The PFP determines warrantyeligibility.

1. Determine the cause of the failure. Thrust / anti-thrust scuffing can be caused by the following conditions:a. Improper Air Fuel Ratio (AFR):

Boost leak Plugged air filer Improperly fueling injector

b. Inadequate clearance between the piston skirt and cylinder liner (Piston overheat / expansion)c. Inadequate lubrication:

Poor oil quality Incorrect oil viscosity Oil dilution Low oil pressure

2. Replace the following components:a. Any complete scuffed cylinder kit (piston assembly, connecting rod, and cylinder liner)b. All main and connecting rod bearing shells (if coolant was present in the engine lubricating oil)c. Engine lubricating oil and oil filterd. Supporting gaskets and seals

6.4 360 Degree Scuffing360 degree scuffing occurs when the piston and cylinder liner show scuffing all of the way around. The piston rings willtypically be stuck in their grooves and scuffing will be present on the ring lands and both piston skirts. 360 degree scuffingoccurs due to a gross lack of cylinder kit lubrication or extreme heat. Lack of sufficient piston cooling will cause the pistonskirts to expand in the cylinder bore. If a lack of lubrication was present, this should be evident for any of the lubricatedjoints and surfaces such as the piston pin, piston pin bores, and connecting rod bushing. The piston cooling nozzle is the onlymethod of pressurized cylinder kit lubrication and cooling.

See illustrations below for examples of 360 degree scuffing.

6 Scuffing


1. 360 Degree ScuffingFigure 38. Piston Showing 360 Degree Scuffing

1. Extreme Metal Transfer (Galling)Figure 39. Piston Pin Showing Extreme Lack of Lubrication from Insufficient Oiling



1. 360 Degree ScuffingFigure 40. Cylinder Liner with 360 Degree Scuffing

1. Scuffing 2. Debris in Piston Cooling NozzleFigure 41. Plugged Piston Cooling Nozzle Causing a 360 Degree Scuff

6 Scuffing


1. Fracture PointFigure 42. Broken Piston Cooling Nozzle

6.5 Repair StrategyThe following is a recommended repair strategy when a 360 degree scuffing condition has been identified. The primaryfailed part (PFP) must be established to prevent future downtime and make an accurate repair. The PFP determines warrantyeligibility.

1. Determine the cause of the failure. 360 degree scuffing can be caused by the following conditions:a. Damaged or plugged piston cooling nozzle. A stiff wire can be used to check for blockage.b. Low engine oil pressure. There should be a history of low oil pressure fault codes.

2. Replace the following components:a. Any scuffed cylinder kit (piston assembly and cylinder liner).b. Any connecting rod damaged from the failure.c. All main and connecting rod bearing shells (if coolant was present in the engine lubricating oil).d. Engine lubricating oil and oil filter.e. Supporting gaskets and seals.

6.6 Broken Piston Ring ScuffA broken piston ring can cause vertical scuffing or scoring in the cylinder liner. The damage will typically follow the ringtravel area of that particular piston ring.

See illustrations below for examples of broken piston ring scuffing.



1. ScuffingFigure 43. Scuffing from a Broken Top Ring

1. ScuffingFigure 44. Scuffing from a Broken Top Ring

6 Scuffing


Figure 45. Broken Piston Ring

6.7 Repair StrategyThe following is a recommended repair strategy when a cracked or broken piston ring scuffing condition has been identified.The primary failed part (PFP) must be established to prevent future downtime and make an accurate repair. The PFPdetermines warranty eligibility.

1. Determine the cause of the failure. Broken ring scuffing can be caused by the following conditions:a. Over-stressing the piston ring during installation onto the piston.b. Inadequate piston ring gap (butting).c. Physical damage to the piston ring during installation.d. Inadequate piston ring clearance in ring groove.e. Piston ring material defect.

2. Replace the following components:a. Any scuffed cylinder kit (piston assembly and cylinder liner).b. Engine lubricating oil and oil filter.c. Supporting gaskets and seals.

6.8 Bent Connecting Rod ScuffThe cylinder liner and piston can scuff if the connecting rod bends due to an impact to the piston or there is fluid in thecylinder (hydro lock). The bent connecting rod beam will force the piston against the cylinder liner in an unnatural manner.Eventually, this force can cause a scuff. Only a small bend may cause this condition.



Figure 46. Effects of a Bent Connecting RodThe illustrations below show an example of a bent connecting rod scuff. Notice the second ring land is scuffed on only halfof the surface and does not align with the thrust or anti-thrust sides of the piston.

1. Skirt Scuffing on Anti-Thrust Side of Piston2. Half of Ring Land Scuffed - Toward Front of Engine

3. Half of Ring Land with No Scuffing - Toward Rear ofEngine

Figure 47. Bent Connecting Rod Scuff Viewed from Anti-Thrust Side

6 Scuffing


1. Skirt Scuffing on Thrust Side of Piston2. Half of Ring Land No Scuffing - Toward Rear of Engine

3. Half of Ring Land Scuffed - Toward Front of Engine

Figure 48. Bent Connecting Rod Scuff Viewed from Thrust SideDepending on the location and severity of the rod bend, there may also be a nick in the bottom of the cylinder liner where thebeam of the connecting rod made contact.

6.9 Repair StrategyA connecting rod will only bend if the piston is impacted or stopped in its upward stroke. The root cause must be found todetermine the Primary Failed Part (PFP) and make an accurate repair. The PFP determines warranty eligibility.

1. Determine the cause of the failure. A bent connecting rod can be caused by the following conditions:a. Piston to valve contact:

Engine out of time Mechanically seized engine brake rocker arm(s) Rocker arm or overhead damage Dropped valve Piston installed backwards

b. Foreign Object Damage (FOD) from material entering the cylinder.c. Hydro lock of the piston from fluid in the cylinder:

Fuel (Fuel Injector) Coolant (EGR Cooler) Oil (Turbocharger) Ether (Starting Fluid) Water ingestion

2. Measure piston protrusion for all cylinders to verify there are no other bent connecting rods.3. Replace the following components:

a. Any scuffed cylinder kit (piston assembly and cylinder liner).b. Any bent connecting rod.c. All main and connecting rod bearing shells (if coolant was present in the engine lubricating oil).d. Engine lubricating oil and oil filter.



e. Supporting gaskets and seals.

6 Scuffing


7 Cylinder Kit Wear Out

7.1 Cylinder Kit Wear OutThe wear rate of parts in any engine will vary depending on operating conditions and operating environment. Conditions suchas load, trailer configuration, road speed and road conditions, as well as quality of air, fuel, lube oil and lube oil filters bear adirect relationship to the wear rate and resulting life of parts. Depending upon the severity of the various conditions, partswear could result in cylinder kit wear out. Wear out occurs through normal wear until the components no longer perform ormeet the desired expectation.

The DD Platform heavy duty engine will provide a long life for a customer if oil, coolant, and duty cycles are maintainedproperly. Higher horsepower and higher duty cycle tends to increase all engine wear factors. Increased fuel consumptionfrom the following conditions will have an effect of reducing engine life to wear out:

Gross vehicle weights greater than 80,000 lbs. Higher average engine speeds over 1800 RPM. Average load factors greater than 54%.

Even keeping these conditions to a minimum, eventually the engine will require an overhaul.

An engine that is worn out may show a number of the following symptoms:

Excessive oil consumption Low compression High crankcase pressure or smoke from the breather High wear metals observed during an oil analysis White or blue smoke (aftertreatment device may reduce amount of visible smoke) A trend of higher fuel consumption Low wheel horsepower Hard starting (especially in colder weather)

7.2 LinerA cylinder liner that is worn out looks similar to a liner that has experienced a dust out condition. The liner hone will bealmost non-existent through the entire stroke of the piston and there may be a significant wear step at the ring reversal areas.



1. Vertical Scoring 2. No Remaining Crosshatch / HoneFigure 49. Worn Out Cylinder Liner

1. No Crosshatch PresentFigure 50. Worn Out Cylinder Liner



7.3 Piston and RingsAs mentioned earlier, cylinder kit wear out typically results in high oil consumption. The pistons will likely show abnormalburnt carbon deposits on the domes and possibly the ring lands. The piston rings may show accelerated wear. The oil controlring may have worn down (plateaued) scraper rails and the coatings could be completely missing from the top and secondrings.

1. Carbon Deposits from Excessive Oil ConsumptionFigure 51. Carbon Deposits on Piston Dome



1. Worn Out Oil Control Ring Scraper Rails 2. Worn Out Top and Second RingsFigure 52. Worn Out Piston Rings

7.4 Repair StrategyThe following is a recommended repair strategy when a wear out condition has been identified.

1. Replace the following components:a. All six cylinder kits (pistons assemblies and cylinder liners).b. All six connecting rods.c. All main and connecting rod bearing shells.d. Engine lubricating oil and oil filter.e. Supporting gaskets and seals.

2. Educate the owner / operator of the vehicle. Engine wear can be improved with proper maintenance practices and lesssevere duty cycles.



8 Cracked Piston and Impact Damage

8.1 Cracked Piston and Impact DamageA cracked piston may lead to a low compression issue or cylinder misfire codes. Pistons can be damaged by foreign materialentering the cylinder, a material defect, or Piston-to-Valve Contact (PTV).

1. CrackFigure 53. Cracked Piston



1. Valve Impact MarkFigure 56. Piston to Valve Contact (PTV) - Rear Exhaust Valve

1. Valve Impact MarkFigure 57. Piston to Valve Contact (PTV) - Forward Intake Valve



1. Impact MarksFigure 58. Foreign Object Damage to Piston (FOD)

Figure 59. Foreign Object Damage to Piston (FOD)



8.2 Repair StrategyThe following is a recommended repair strategy when a cracked or impacted piston has been identified. The root cause mustbe found to determine the Primary Failed Part (PFP) and make an accurate repair. The PFP determines warranty eligibility.

1. Determine the cause of the failure. Cracked or impacted pistons can be caused by:a. Foreign material in the cylinderb. Piston material defectc. Piston-to-Valve Contact (PTV)

Engine out of time Mechanically seized engine brake rocker arm(s) Rocker arm or overhead damage Piston installed backwards Dropped valve

2. Measure the piston protrusion for all six cylinders to check for bent connecting rods.3. Thoroughly inspect all pistons for damage if foreign material was present. Debris can migrate to other cylinders.4. Replace the following components:

a. Any damaged cylinder kit (pistons assemblies and cylinder liners)b. The connecting rod in the damaged cylinderc. Any bent connecting rodd. Engine lubricating oil and oil filtere. Supporting gaskets and seals



9 Piston Dome Separation

9.1 Piston Dome SeparationPiston dome separation is rare on DD platform heavy duty engines, but does still occur. The piston dome is a two piecedesign and is friction welded together. This weld could fail and result in separation. Dome separation is typically an isolatedfailure affecting one piston, although the debris from the failure can migrate to other cylinders and components. The pistondome friction welding process was improved in October of 2014 to address this failure.

Figure 60. Piston Dome Separation

9 Piston Dome Separation


Figure 61. Piston Dome Separation

9.2 Repair StrategyThe following is a recommended repair strategy when a piston dome separation failure has been identified.

1. Thoroughly inspect the tops of all pistons for damage. Debris from the failure can migrate to other cylinders.2. Measure the piston protrusion for all six cylinders to check for any bent connecting rods.3. Inspect the turbocharger for progressive damage (any time there is debris that exits a cylinder).4. Replace the following components:

a. Any damaged cylinder kit (pistons assemblies and cylinder liners)b. The connecting rod in the damaged cylinder(s)c. Any bent connecting rodd. All main and connecting rod bearing shells (if coolant was present in the engine lubricating oile. Cylinder headf. Exhaust Gas Recirculation (EGR) cooler (replace any time there is debris that exits a cylinder)g. Engine lubricating oil and oil filterh. Supporting gaskets and seals



10 Piston Pin Failure

10.1 Piston Pin FailurePiston pins fractures occur when there is a material defect in the pin. Typically, this only causes damage to an isolatedcylinder. However, if the driver continues to operate the engine, the connecting rod can exit the cylinder block. The design ofthe piston pin was improved in March of 2014 to address this failure.

Figure 62. Failed Piston Pin



Figure 63. Connecting Rod Bushing Damage from a Failed Piston Pin

Figure 64. Cylinder Liner Damage from a Failed Piston Pin

10.2 Repair StrategyThe following is a recommended repair strategy when a piston pin failure has been identified.



1. Thoroughly inspect the tops of all pistons for damage from migrating debris.2. Measure the piston protrusion for all six cylinders to check for any bent connecting rods.3. Inspect the turbocharger for progressive damage (if debris exited a cylinder).4. Replace the following components:

a. Any damaged cylinder kit (pistons assemblies and cylinder liners)b. The connecting rod in the damaged cylinderc. Any bent connecting rodd. All main and connecting rod bearing shells (if coolant was present in the engine lubricating oile. Cylinder head (if damaged by the failure)f. Exhaust Gas Recirculation (EGR) cooler (if debris exited a cylinder)g. Engine lubricating oil and oil filterh. Supporting gaskets and seals



11 Upper Liner O-ring Failure

11.1 Upper Liner O-ring FailureUpper liner O-ring failure (cracks / deterioration) typically results in coolant between the cylinder head and cylinder block.This coolant can leak from the cylinder head joint and result in coolant running down the cylinder block. The upper liner O-ring material was improved for DD13 engines in March of 2011 and DD15/DD16 engines in September of 2012. Failures ofthe O-ring after these change points are rare, and can usually be attributed to low engine coolant levels, engine overheatevents, or NOAT coolant breakdown.

It is important to distinguish between a coolant grommet failure on the head gasket and an upper liner O-ring failure. Theycan both result in similar external coolant leaks down the cylinder block. Inspect the head gasket carefully upon removal.Failures of the head gasket coolant grommets occur more frequently than upper liner O-ring failures.

See illustrations below for examples of upper liner O-ring failures and cylinder block corrosion.

1. Leaking O-ring 2. Rust / CorrosionFigure 65. Failed Upper Liner O-ring with Liner Corrosion



1. CorrosionFigure 66. Cylinder Block Corrosion from a Failed Upper Liner O-ring

1. CorrosionFigure 67. Cylinder Block Corrosion from a Failed Upper Liner O-ring

11 Upper Liner O-ring Failure


11.2 Repair StrategyThe following is a recommended repair strategy when an upper liner O-ring failure has been identified.

1. Remove all six cylinder liners to inspect the upper liner O-rings.2. Carefully clean the upper cylinder block counterbores to remove any rust or scale. Place a shop towel or rag in the

cylinder to catch any debris and protect the crankshaft journals.3. Replace any cylinder liner with corrosion from a leaking upper liner O-ring.4. Re-seal and reinstall any liners that do not show corrosion at the upper liner O-ring groove. All new upper liner O-

rings released for service are 0.2 mm larger in height and width to address corrosion of the cylinder block caused byleaking O-rings.

5. Reinstall original pistons, piston rings, and connecting rods if not damaged.6. Replace all main and connecting rod bearing shells (if coolant was present in the engine lubricating oil.7. Replace the engine lubricating oil and oil filter.8. Replace any supporting gaskets and seals.



12 Liner Cavitation

12.1 Liner CavitationCylinder liner cavitation occurs when the cooling system is not properly maintained. This is a rare failure for DD platformheavy duty engines but can still happen. Air bubbles form in the cooling system near the cylinder liners during normaloperation, similar to boiling water. Supplemental Coolant Additives (SCAs) create a protective layer on the outside of theliners. Without the proper additives and protective layer, the bubbles in the cooling system implode on the outside of theliners and cause pitting over time. Cylinder liner cavitation can occur with as little as 50,000 miles (80,000 km). Severe linercavitation can cause engine oil to enter the cooling system.

1. Cavitation / Erosion PittingFigure 68. Liner Cavitation

12 Liner Cavitation


1. Cavitation / Erosion PittingFigure 69. Liner Cavitation

12.2 Repair StrategyThe following is a recommended repair strategy when a cylinder liner cavitation condition has been identified.

1. Replace all six cylinder liners.2. Replace all main and connecting rod bearing shells (if coolant was present in the engine lubricating oil).3. Replace the engine lubricating oil and oil filter.4. Check and replace the surge tank pressure cap as necessary.5. Thoroughly flush the cooling system and refill with the proper coolant mixture.6. Educate the vehicle owner / operator on proper cooling system maintenance.



13 Vertical Failure vs. Horizontal Failure

13.1 Vertical Failure vs. Horizontal FailureThere are two general failure modes for the DD platform heavy duty engine; vertical failure and horizontal failure. Knowingthe difference between the two can help when trying to determine the root cause of a failure.

A vertical or isolated failure typically involves a single component:

Fuel Injector Rocker arm / engine brake Intake or exhaust valve Single main or connecting rod bearing Single cylinder

Horizontal or system failures typically have more than one of the same components damaged or failed:

Multiple fuel injectors Multiple rocker arms / engine brakes Multiple intake or exhaust valves Multiple main or connecting rod bearings Multiple damaged cylinders

13 Vertical Failure vs. Horizontal Failure


1. Vertical (Isolated) Failure 2. Horizontal (Systematic) FailureFigure 70. Vertical vs. Horizontal FailureA failure in the engine lubrication system, cooling system, or air system can cause horizontal engine component failures.Horizontal failures can also be caused by poor maintenance practices, engine overspeed events, an improper air-fuel-ratio(AFR), or debris.



1 DD Platform Heavy Duty Cylinder Kit Inspection Guide2 Warranty2.1 Warranty

3 Cylinder Kit Overview3.1 Cylinder Block and Liner3.2 Piston and Connecting Rod

4 Normal Wear4.1 Normal Wear4.2 Piston4.3 Piston Rings4.4 Piston Pin4.5 Connecting Rod4.6 Cylinder Liner

5 Dust Out5.1 Dust Out5.2 Cylinder Liner5.3 Piston and Piston Rings5.4 Piston Pin5.5 Repair Strategy

6 Scuffing6.1 Scuffing6.2 Thrust and Anti-Thrust Scuffing6.3 Repair Strategy6.4 360 Degree Scuffing6.5 Repair Strategy6.6 Broken Piston Ring Scuff6.7 Repair Strategy6.8 Bent Connecting Rod Scuff6.9 Repair Strategy

7 Cylinder Kit Wear Out7.1 Cylinder Kit Wear Out7.2 Liner7.3 Piston and Rings7.4 Repair Strategy

8 Cracked Piston and Impact Damage8.1 Cracked Piston and Impact Damage8.2 Repair Strategy

9 Piston Dome Separation9.1 Piston Dome Separation9.2 Repair Strategy

10 Piston Pin Failure10.1 Piston Pin Failure10.2 Repair Strategy

11 Upper Liner O-ring Failure11.1 Upper Liner O-ring Failure11.2 Repair Strategy

12 Liner Cavitation12.1 Liner Cavitation12.2 Repair Strategy

13 Vertical Failure vs. Horizontal Failure13.1 Vertical Failure vs. Horizontal Failure

DD Platform Heavy Duty Cylinder Kit Inspection Guideddcsn-ddc.freightliner.com/cps/rde/xbcr/ddcsn/DDC-SVC-MAN-0199.pdf · 1 DD Platform Heavy Duty Cylinder Kit Inspection ... connecting

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