Comprehensive 6.6L L5P Duramax Maintenance Guide
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 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 Type | Miles | Kilometers |
| Change Oil | 7,500 Miles | 12,000 km |
| Replace Oil Filter | 7,500 Miles | 12,000 km |
| Change Fuel Filters | 22,500 miles or when dash light comes on | 34,000 km |
| Replace Air Filter | 45,000 miles or every 4 years | 72,000 km |
| Flush Cooling System | 150,000 miles or every 5 years | 240,000 km |
| Replace Transmission Fluid | 97,500 miles | 156,000 km |
| Change external transmission filter | 45,000 miles | 72,000 km |
| Replace Internal Transmission Filter | 97,500 miles under normal driving conditions | 156,000 km |
| Change Transfer Case Fluid | 45,000 miles | 72,000 km |
| Replace Differential Fluid | Not 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/Service | Miles | Kilometers |
| Change Oil | 7,500 miles | 12,000 km |
| Replace Oil Filter | 7,500 miles | 12,000 km |
| Change Fuel Filter | 22,500 miles | 34,000 km |
| Replace Air Filter | 45,000 miles | 72,000 km |
| Flush Cooling System | 150,000 miles | 240,000 km |
| Replace Transmission Fluid | 45,000 miles | 72,000 km |
| Change External transmission filter | 45,000 miles | 72,000 km |
| Change internal transmission filter | 45,000 miles | 72,000 km |
| Replace Transfer Case Fluid | Not listed in owner’s manual 45,000 miles Recommended | 72,000 km |
| Replace Differential Fluid | Not 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 Type | Capacity – Quarts | Capacity – Liters |
| Engine oil /w Filter | 10.0 Quarts | 9.5 Liters |
| Auto. Transmission Fluid (Pan Removal & Filter Replacement) | 7.4 Quarts | 7.0 Liters |
| Transfer Case | 1.6 Quarts | 1.5 Liters |
| Coolant | 31.4 Quarts | 29.7 Liters |
| Front Differential Fluid | Unknown | Unknown |
| Rear Differential Fluid | Unknown | Unknown |
| DEF Tank | 7 Gallons | 26.5 Liters |
| Oil/Fluid | Year | Capacity – Quarts | Capacity – Liters |
| Engine Oil /w Filter | 2020+ | 10.0 qt | 9.5 Liters |
| Auto Transmission Fluid (Pan Removal & Filter Change) | 2020+ | 7.4 qt | 7.0 Liters |
| Transfer Case | 2020+ | 2.4 qt | 2.3 Liters |
| Coolant | 2020+ | 30.7 qt | 29.1 Liters |
| Low Temp. Circuit Cooling System | 2020+ | 3.7 qt | 3.5 Liters |
| Front Differential Fluid | 2020+ | Unknown | Unknown |
| Rear Differential Fluid | 2020+ | Unknown | Unknown |
| DEF Tank (Diesel Exhaust Fluid) | 2020+ | 7 gallons or 28 qt | 26.5 Liters |
| Hydraulic Power Steering Fluid | 2020+ | 2.1 qt | 2.0 Liters |
2017-2019 L5P Duramax Maintenance Parts & Fluids
| Part Type | Part # | Amazon Link |
| Engine Oil | 15W-40 | Shell Rotella T4 15W40 ACDelco 15W40 Shell Rotella T5 (blend ) 15W40 Shell Rotella T6 (Full Syn.) 15W40 |
| Engine Oil Filter | PF2232 | ACDelco PF2232 (1-pack) |
| Fuel Filter | TP1015 | ACDelco TP1015 |
| Cabin Air Filter | CF 188 | ACDelco CF188 |
| Engine Air Filter | A3231C | ACDelco A3231C |
| Coolant | Dex-Cool 12346290 50/50 Mix | Dex-Cool 12346290 |
| Transmission Fluid | Dexron VI | 1 qt – Dexron VI 1 Gal – Dexron VI |
| External Transmission Filter | 29539579 TF950 | Allison 29539579 ACDelco TF950 |
| Internal Transmission Filter | 29542833 | ACDelco 29542833 |
| Transmission pan gasket | 29549684 | ACDelco 29549684 |
| Transfer Case Fluid | Dexron VI | 1 qt – Dexron VI 1 Gal – Dexron VI |
| Differential Fluid | 75W90 | ACDelco 75W90 |
| Diesel Exhaust Fluid | N/A | Peak BlueDEF |
| Part Type | Part # | Amazon Link |
| Engine Oil | 15W40 | Shell Rotella T4 15W40 ACDelco 15W40 Shell Rotella T5 (blend ) 15W40 Shell Rotella T6 (Full Syn.) 15W40 |
| Coolant | Dex-Cool 12346290 50/50 Mix | Dex-Cool 12346290 |
| Hydraulic Power Steering Fluid | GM 19329450 | GM 19329450 |
| Transmission Fluid (6-Speed Automatic) | Dexron VI | 1 qt – Dexron VI 1 Gal – Dexron VI |
| Transfer Case Fluid | Dexron VI | 1 qt – Dexron VI 1 Gal – Dexron VI |
| Front Differential Fluid | 75W-90 | ACDelco 75W90 |
| Rear Differential Fluid | 75W-90 | ACDelco 75W-90 |
| Diesel Exhaust Fluid | N/A | Peak BlueDEF |
2020+ L5P Duramax Maintenance Parts, Fluids, and Oil
| Part Type | Part # |
| Engine Oil | 15W-40 ACDelco 15W-40 Shell Rotella T4 15W-40 Shell Rotella T5 15W-40 |
| Engine Oil Filter | PF26 |
| Fuel Filter | TP1015 |
| Cabin Air Filter | CF 185 |
| Engine Air Filter | A3248C |
| Coolant | Dex-Cool 12346290 50/50 Mix Dex-Cool Coolant and Distilled Water |
| Transmission Fluid | Dexron ULV |
| Transmission Filter | unknown |
| Transmission pan gasket | unknown |
| Transfer Case Fluid | Dexron VI |
| Differential Fluid | unknown |
| Diesel Exhaust Fluid | N/A |
| Part Type | Part # | Amazon Link |
| Engine Oil | 15W-40 | ACDelco 15W-40 Shell Rotella T4 15W-40 Shell Rotella T5 15W-40 |
| Coolant | Dex-Cool 12346290 50/50 Mix | Dex-Cool 12346290 |
| Transmission Fluid (10-Speed Automatic) | Dexron ULV | Dexron ULV |
| Transfer Case Fluid | Dexron VI | Dexron VI |
| Front Differential Fluid | unknown | unknown |
| Rear Differential Fluid | unknown | unknown |
| Diesel Exhaust Fluid | N/A | Peak BlueDEF |
L5P Duramax Fuel Capacity
| Model | Fuel Tank Capacity (Gallons) |
| 2500 & 3500 Crew Cab | 36 Gallons |
| 2500 & 3500 Double Cab Short Bed | 29.4 Gallons |
| 2500 & 3500 Double Cab Long Bed | 36 Gallons |
| Regular Cab | 28 Gallons |
Find out more about the L5P Duramax By Reading our other articles.
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