Kenworth W series

Manual transmission fluid capacity & service interval

Kenworth W series manual transmission fluid capacity is 13 liters. Service intervals include checks at 15000 miles or 12 months, and changes at 180000 miles or 36 months and 500000 miles or 60 months. The data covers 4 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
W900L "ICON", Cummins ISX15 (2015-2016)
  • Use: Normal
  • Capacity 13 liter
  • Check 15000 miles/ 12 months
  • Change 500000 miles/ 60 months
  • Code: Eaton-Fuller RTLO18918 18/2
W900L "ICON", Cummins ISX15 (2015-2016)
  • Use: Severe
  • Capacity 13 liter
  • Check 15000 miles/ 12 months
  • Change 180000 miles/ 36 months
  • Code: Eaton-Fuller RTLO18918 18/2
W900L "ICON", Cat CT15 (2015-2016)
  • Use: Normal
  • Capacity 13 liter
  • Check 15000 miles/ 12 months
  • Change 500000 miles/ 60 months
  • Code: Eaton-Fuller RTLO18918 18/2
W900L "ICON", Cat CT15 (2015-2016)
  • Use: Severe
  • Capacity 13 liter
  • Check 15000 miles/ 12 months
  • Change 180000 miles/ 36 months
  • Code: Eaton-Fuller RTLO18918 18/2

Additional Notes

  • The Kenworth W series W900L "ICON" carries a manual transmission fluid capacity of 13 liters across all four listed configurations, covering both the Cat CT15 and Cummins ISX15 engine pairings for 2015-2016.
  • A 13-liter capacity in a heavy-duty manual transmission is consistent with large multi-speed gearboxes commonly found in Class 8 vocational trucks, where fluid volume supports lubrication across a wide gear range under sustained load.
  • The check interval is set at 15,000 miles or 12 months for all four configurations, regardless of whether the use condition is normal or severe.
  • Under normal use conditions, the fluid change interval for the Cat CT15 configuration reaches 500,000 miles or 60 months, reflecting an extended-drain specification suited to long-haul operation with stable thermal and load cycles.
  • Under severe use conditions, the Cat CT15 configuration carries a change interval of 180,000 miles or 36 months, representing a reduction of more than 60 percent compared to the normal-use interval in mileage terms.
  • The Cummins ISX15 configuration mirrors the Cat CT15 exactly across both use conditions, with a 500,000-mile or 60-month change interval under normal use and a 180,000-mile or 36-month interval under severe use.
  • The alignment of capacity and interval figures between the Cat CT15 and Cummins ISX15 pairings in 2015-2016 indicates that the transmission unit, rather than the engine, governs the fluid service specifications in these configurations.