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Comprehensive 6.6L L5P Duramax Maintenance Guide

L5P Duramax Maintenance Schedule & Service Intervals

2017+ Chevrolet Silverado HD & GMC Sierra HD Diesel Service Schedule

As with all automobiles, proper maintenance plays a crucial role in increasing the useful life of your truck. This is especially important on modern diesels like the newest 6.6L Duramax. They’re very powerful and capable, but they’re also very vulnerable to poor fuel quality. Luckily, this can be addressed by following the proper L5P Duramax Maintenance schedule. You shouldn’t try and see how long you can go without changing your oil or replacing your fuel filters. While sometimes maintenance can be expensive, it’s worth the investment. You shouldn’t cheap out on good quality oil or fluids too. I use only high quality oils and fluids in my trucks. Anything you choose should meet or exceed OEM standards.

Looking to maintain your truck by yourself? Check out the charts below to determine when you need to perform regular maintenance tasks on your L5P. Please keep in mind that you should always double check your owners manual or contact GM directly to make sure anything you purchase will work properly with your truck. You can also visit our Fluid Capacity & Recommendations for the L5P resource to find out what type of fluid and oil you need. The charts listed below are based off of GM’s recommended L5P Duramax Maintenance and Service schedule.

L5P Duramax Tuning

L5P Duramax Maintenance & Service Intervals

The chart below shows general L5P Duramax maintenance and service intervals. Please keep in mind your situation may call for more frequent maintenance than what is listed below. Heavy towing or driving in extreme conditions requires more frequent maintenance. When you change your oil, check components like your air filter to make sure they are still okay. You might have to change them earlier than GM’s recommended service intervals. If your dash light comes on for something needing to be serviced, service your truck as soon as possible. Listed below are GM’s recommended maintenance schedule for trucks that are driven under normal conditions.

L5P Duramax Maintenance & Service Schedule (Normal Operating Conditions)

Maintenance/Service TypeMilesKilometers
Change Oil7,500 Miles12,000 km
Replace Oil Filter7,500 Miles12,000 km
Change Fuel Filters22,500 miles or when dash
light comes on
34,000 km
Replace Air Filter45,000 miles or every 4 years72,000 km
Flush Cooling System150,000 miles or every 5 years240,000 km
Replace Transmission
Fluid
97,500 miles156,000 km
Change external
transmission filter
45,000 miles72,000 km
Replace Internal
Transmission Filter
97,500 miles under normal
driving conditions
156,000 km
Change Transfer
Case Fluid
45,000 miles72,000 km
Replace Differential FluidNot Mentioned in Owner’s
Manual
We Recommend changing
every 30-60,000 miles. If
you submerge your axles
in water or mud, change your
diff. fluid immediately
48,280 km-
96560 km

Maintenance & Service Schedule (Severe Operating Conditions)

Maintenance/ServiceMilesKilometers
Change Oil7,500 miles12,000 km
Replace Oil
Filter
7,500 miles12,000 km
Change Fuel
Filter
22,500 miles34,000 km
Replace Air
Filter
45,000 miles72,000 km
Flush Cooling
System
150,000 miles240,000 km
Replace Transmission
Fluid
45,000 miles72,000 km
Change External
transmission filter
45,000 miles72,000 km
Change internal
transmission filter
45,000 miles72,000 km
Replace Transfer
Case Fluid
Not listed in
owner’s manual
45,000 miles
Recommended
72,000 km
Replace Differential FluidNot Mentioned in Owner’s
Manual
We Recommend at least
every 30-60,000 miles. If
you submerge your axles
in water or mud, change your
diff. fluid immediately.
48,280 km-
96560 km

Now that you know when you should complete general maintenance tasks on your truck, you need the parts and fluids to keep your truck in tip-top shape! Everything you need is listed below. Check it out! All of these products are listed with links to purchase them. These links are affiliate links. When you purchase one of the products from the links below, we receive a commission. Thanks for your support!

L5P Duramax Fluid Capacity

While our guide will give you the manufacturer’s recommended fluid capacity for the L5P Duramax, you always need to check your dipsticks and tank levels. Do not fill over the max line on a reservoir, tank, or dip stick. Add fluid or oil if you are at or below the fill or minimum mark. For more instructions on adding fluid or oil to your truck, see your L5P Duramax owner’s manual.

Oil/Fluid TypeCapacity – QuartsCapacity – Liters
Engine oil /w
Filter
10.0 Quarts9.5 Liters
Auto. Transmission
Fluid (Pan Removal
& Filter Replacement)
7.4 Quarts7.0 Liters
Transfer Case1.6 Quarts1.5 Liters
Coolant31.4 Quarts29.7 Liters
Front Differential
Fluid
UnknownUnknown
Rear Differential
Fluid
UnknownUnknown
DEF Tank7 Gallons26.5 Liters
Oil/FluidYearCapacity – QuartsCapacity – Liters
Engine Oil /w Filter2020+10.0 qt9.5 Liters
Auto Transmission
Fluid (Pan Removal
& Filter Change)
2020+7.4 qt7.0 Liters
Transfer Case
2020+2.4 qt2.3 Liters
Coolant2020+30.7 qt29.1 Liters
Low Temp. Circuit
Cooling System
2020+3.7 qt3.5 Liters
Front Differential
Fluid
2020+UnknownUnknown
Rear Differential
Fluid
2020+UnknownUnknown
DEF Tank
(Diesel Exhaust
Fluid)
2020+7 gallons or 28 qt26.5 Liters
Hydraulic Power
Steering Fluid
2020+2.1 qt2.0 Liters

2017-2019 L5P Duramax Maintenance Parts & Fluids

Part TypePart #Amazon Link
Engine Oil15W-40Shell Rotella T4 15W40
ACDelco 15W40
Shell Rotella T5 (blend ) 15W40
Shell Rotella T6 (Full Syn.) 15W40

Engine Oil FilterPF2232ACDelco PF2232 (1-pack)
Fuel FilterTP1015ACDelco TP1015
Cabin Air FilterCF 188ACDelco CF188
Engine Air FilterA3231CACDelco A3231C
CoolantDex-Cool
12346290
50/50 Mix
Dex-Cool 12346290
Transmission FluidDexron VI1 qt – Dexron VI
1 Gal – Dexron VI
External Transmission
Filter
29539579
TF950
Allison 29539579
ACDelco TF950
Internal Transmission
Filter
29542833ACDelco 29542833
Transmission pan
gasket
29549684ACDelco 29549684
Transfer Case FluidDexron VI1 qt – Dexron VI
1 Gal – Dexron VI
Differential Fluid75W90ACDelco 75W90
Diesel Exhaust FluidN/APeak BlueDEF
Part TypePart #Amazon Link
Engine Oil15W40Shell Rotella T4 15W40
ACDelco 15W40
Shell Rotella T5 (blend ) 15W40
Shell Rotella T6 (Full Syn.) 15W40
CoolantDex-Cool
12346290
50/50 Mix
Dex-Cool 12346290
Hydraulic Power
Steering Fluid
GM
19329450
GM 19329450
Transmission Fluid
(6-Speed Automatic)
Dexron VI1 qt – Dexron VI
1 Gal – Dexron VI
Transfer Case FluidDexron VI1 qt – Dexron VI
1 Gal – Dexron VI
Front Differential
Fluid
75W-90ACDelco 75W90
Rear Differential Fluid75W-90 ACDelco 75W-90
Diesel Exhaust FluidN/APeak BlueDEF

2020+ L5P Duramax Maintenance Parts, Fluids, and Oil

Part TypePart #
Engine Oil15W-40
ACDelco 15W-40
Shell Rotella T4 15W-40
Shell Rotella T5 15W-40
Engine Oil FilterPF26
Fuel FilterTP1015
Cabin Air FilterCF 185
Engine Air FilterA3248C
CoolantDex-Cool
12346290
50/50 Mix Dex-Cool Coolant
and Distilled Water
Transmission FluidDexron ULV
Transmission
Filter
unknown
Transmission pan
gasket
unknown
Transfer Case FluidDexron VI
Differential Fluidunknown
Diesel Exhaust FluidN/A
Part TypePart #Amazon Link
Engine Oil15W-40ACDelco 15W-40
Shell Rotella T4 15W-40
Shell Rotella T5 15W-40
CoolantDex-Cool
12346290
50/50 Mix
Dex-Cool 12346290
Transmission Fluid
(10-Speed Automatic)
Dexron ULVDexron ULV
Transfer Case FluidDexron VIDexron VI
Front Differential Fluidunknownunknown
Rear Differential Fluidunknownunknown
Diesel Exhaust FluidN/APeak BlueDEF

L5P Duramax Fuel Capacity

ModelFuel Tank Capacity (Gallons)
2500 & 3500 Crew Cab36 Gallons
2500 & 3500 Double Cab
Short Bed
29.4 Gallons
2500 & 3500 Double Cab
Long Bed
36 Gallons
Regular Cab28 Gallons

Find out more about the L5P Duramax By Reading our other articles.

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Founder of Diesel Resource and a complete diesel head. Has a little bit of problem buying too many trucks. Learn more about him by checking out his truck.