6.6L Duramax LML Maintenance Schedule & Service Guide | 2011 - 2016 Duramax Diesel

Applicable Models:

2011 - 2016 Chevrolet Silverado 2500/3500
2011 - 2016 GMC Sierra 2500/3500

Applicable Engine(s):

6.6L Duramax diesel LML
(8th digit of VIN "8", see Duramax VIN ID for additional information)

Applicable Transmission(s):

Allison 1000 six speed automatic

Missing the owners manual from your 2011 to 2016 Chevy Silverado or GMC Sierra? Misplaced your LML Duramax diesel supplement? Or maybe you're in need or more comprehensive service information for your 6.6L Duramax. In any event, we've got you covered.

6.6L Duramax LML Maintenance Schedule (Service Intervals)

"Severe duty" service conditions may include any of the following:

• Light towing that exceeds 1,000 miles during any applicable service interval.
• Medium to heavy towing or hauling payloads that place the vehicle near its maximum GVWR.
• Extended periods of idling, generally accepted as 10 minutes of idling or more during a 60 minute window.
• Driving off-road or in dusty conditions.
• Frequent driving in heavy stop-and-go traffic conditions.
• Driving in a manner that prevents the engine from reaching normal operating temperature (frequent stops and/or short trips).


Service Interval(s)


Replace engine oil & oil filter

10,000 miles or when "change engine oil" message is displayed by the oil life monitoring system


Replace fuel filter, drain water separator

22,500 miles/2 years or when "change fuel filter" message is displayed


Replace engine air filter

45,000 miles/4 years or when "replace engine air filter" message is displayed


Perform engine cooling system service

150,000 miles/5 years


Replace automatic transmission fluid & filters

Replace external filter at 45,000 mile intervals and full service at 97,500 miles under normal conditions
Perform full service every 45,000 miles under severe duty conditions


Replace transfer case fluid

97,500 miles (normal conditions)
22,500 miles (severe duty conditions)


Replace front differential fluid

50,000 miles

[5], [6]

Replace rear differential fluid

Perform multi-point inspection

At oil change intervals


[1] Do not exceed 10,000 miles between oil changes. More frequent oil changes may be advisable if towing frequently, hauling payloads near GVWR, or idling for extended periods of time. Recommend changing engine oil every 12 months if mileage does not meet service criteria.
[2] Check air filter condition at oil change intervals and replace as necessary. Driving in dusty conditions will require more frequent air filter replacements.
[3] At minimal, drain coolant from engine cooling system and replace thermostats, upper radiator hose, lower radiator hose, and replenish with new coolant/distilled water solution. Inspect remaining hoses and overflow tank, replace as necessary. Recommend that subsequent cooling system services are performed at 50,000 mile intervals after the initial 150,000 mile service.
[4] Replace external and internal transmission filters, replenish with new automatic transmission fluid; recommend adhering to severe duty service intervals.
[5] Replace transfer case and differential fluid immediately anytime these components are submerged in water; water infiltration is highly likely.
[6] No service interval provided by GM; recommend replacing front and rear differential gear oil at 50,000 mile intervals to prolong life.
[7] Multi-point inspection should include examination of ball joints, universal joints, CV joints, air filter, fuel system (leak detection), exhaust system, and vehicle brake condition. Grease applicable Zerk fittings as required.

6.6L Duramax LML Service Parts List

Part Description

Part Number

Engine air filter

ACDelco A3141C

Engine oil filter

ACDelco PF2232

Oil pan drain plug

GM 11569943

Oil fill cap

ACDelco FC239

Fuel filter

ACDelco TP3018

Serpentine belt

ACDelco 6K1195, Gates K061195


Front, 2011 - 2014 models

ACDelco 12T100D

Rear, 2011 - 2014 models

ACDelco 12T99D

2015 -2016 models

ACDelco 131-131

Thermostat housing gasket

ACDelco 97223686

Coolant reservoir cap

ACDelco RC115

Upper radiator hose

2011 - 2014 models

ACDelco 27035X, Gates 23721

2015 - 2016 models

GM 22884211, Dayco 72554

Lower radiator hose

2011 - 2014 models

ACDelco 27099X, Gates 23962

2015 - 2016 models

Gates 51464

Glow plug

ACDelco 9G (replaces ACDelco 61G)

Automatic transmission filter, auxiliary (external)

ACDelco TF950, Allison 29539579

Automatic transmission filter, internal

GM 29542833

Transmission pan gasket

GM 29549684

Front differential gasket


Rear differential gasket

14 bolt, GM 10.5

GM 26067159

14 bolt, AAM 11.5

GM 12471447

6.6L Duramax LML Oil & Fluid Specs, Capacities


Oil/Fluid Specification

Capacity [1]

Engine oil [2]

Ambient temp > 0° F

SAE 15W-40 API CJ-4 or CK-4
Recommend Amsoil Max Duty 15W-40 synthetic diesel oil

10 quarts w/ filter change

Ambient temp < 0° F
(acceptable in all temps)

SAE 5W-40 API CJ-4 or CK-4
Recommend Amsoil Max Duty 5W-40 synthetic diesel oil

Engine coolant

50/50 solution DEX-COOL engine coolant concentrate and distilled water
(GM DEX-COOL 12346290)

7.125 gallons

Automatic transmission fluid

GM DEXRON VI automatic transmission fluid
(ACDelco 10-9243)

7.4 quarts service refill
12.7 quarts total capacity

Transfer case fluid

GM DEXRON VI automatic transmission fluid
(ACDelco 10-9243)
Recommend Amsoil Signature Series FE synthetic ATF

1.6 quarts

Front differential fluid

SAE 75W-90 synthetic gear oil
Recommend Amsoil Severe Gear 75W-90 synthetic gear oil

1.8 quarts

Rear differential fluid

14 bolt GM 10.5

SAE 75W-90 synthetic gear oil
Recommend Amsoil Severe Gear 75W-90 synthetic gear oil

3.2 - 3.5 quarts

14 bolt AAM 11.5

4.4 - 5.0 quarts

Diesel exhaust fluid

DEF meeting ISO 22241-1 specifications or equivalent, GM 19286291/ACDelco 10-4022

5.3 gallons

[1] Oil and fluid capacities are nominal; always fill to proper fluid indicator level (i.e. dipstick), fill plug height, or applicable level identifier. Vehicle should be parked on a level surface when checking or adjusting fluid level.
[2] 15W-40 engine oil preferred in ambient temperatures above 0° F. 5W-40 is acceptable in all ambient temperatures, but only preferred (and required) when ambient temperatures are below 0° F.