LML Duramax Fluid Capacity Guide (2011–2016) | Merchant Automotive
Brake Fluid
Capacity: 1–2 qt for full flush
Fluid: DOT 3 or DOT 4
Service Interval: Every 2–3 years under normal use, or every 50,000 miles in severe-duty conditions.
Note: DOT 4 is fully compatible with DOT 3 and may be used for the LML platform, especially in towing or high-heat conditions. It provides higher boiling points and improved performance under heavy braking.
Shop ACDelco Super DOT‑4 Brake Fluid
DEF (Diesel Exhaust Fluid)
Tank Capacity: 5.3–7.0 gal
(5.3 gal on standard cab/short box, up to 7.0 gal on crew cab/long box and chassis cab models)
Fluid: API-certified DEF
Service Interval: Refill as needed; consumption is typically ~2% of fuel use depending on driving conditions.
Front & Rear Differentials
Front capacity: 1.8 qt; Rear capacity: ~4.0 qt
(capacity may vary slightly depending on axle model and vent design — e.g., AAM 11.5" on 2500HD, 3500HD SRW, or DRW; G80 lockers may hold slightly more)
Fluid: 75W‑90 synthetic (GL‑5)
Service Interval: Replace every 50,000 miles under normal use, or 30,000 under towing or heavy load.
Engine Coolant
Capacity: ~26.5 qt (total system)
Type: Dex‑Cool 50/50 premix
Service Interval: Replace every 5 years or 100,000 miles (initial), then every 2–3 years thereafter.
Engine Oil
Capacity: 10.0 qt (with filter)
Fluid: 15W‑40 CJ-4 or CK-4 diesel engine oil
Service Interval: Replace every 7,500 miles (normal); 5,000 miles (severe use/towing).
Power Steering
Capacity: ~2 qt
Fluid: GM Power Steering Fluid or Dexron VI ATF
Service Interval: Inspect every 15,000 miles; flush every 50,000 miles.
Transfer Case
Capacity: 2.0 qt (NV263XHD or MP1225LD)
Fluid: Auto-Trak II or Dexron VI (check transfer case model)
Service Interval: Replace every 50,000 miles under normal use; every 30,000 miles under severe use.
Transmission – Allison 1000 (6‑speed)
Pan & filter change: 7.4 qt / Total capacity: ~13.4 qt
(actual volume depends on cooler line length and torque converter size)
Fluid: Dexron VI / Transynd
Service Interval: Spin-on filter every 15,000 miles; full fluid service every 50,000 miles under severe use.
Shop Deep Pan & Filter Kit