Short answer
Dual-clutch transmission (DCT) fluids are specified by each automaker, usually by part number, rather than by an industry standard. In a wet-clutch DCT the fluid cools and lubricates the clutches as well as the gears, so its friction behavior is critical. In a dry-clutch DCT the clutches run without fluid and the gearbox and controls use separately specified lubricants.
How a DCT uses fluid
A dual-clutch transmission is essentially two automated manual gearboxes sharing one housing, with one clutch for the odd gears and one for the even gears. Shifts happen by handing torque from one clutch to the other.
In a wet-clutch design the clutches run in fluid, which carries heat away and sets how smoothly they engage. In a dry-clutch design the clutches work in air, like a manual transmission, and the gearset and mechatronic or hydraulic controls have their own fluids.
Why DCT fluids are OEM-specific
Friction modifiers in a wet-clutch DCT fluid are tuned to the clutch materials and control software of particular transmissions. Gear protection matters too, since DCT gearsets resemble manual transmission gears. Automakers specify fluids by their own part or standard numbers, and one maker can use different fluids in different DCT models, sometimes even in separate circuits of the same unit.
Even suppliers’ cross-reference charts disagree about which part number goes where for some transmissions, which is a good reason to rely on the manufacturer’s VIN-specific information.
DCTs in powersports
Some motorcycles, ATVs and UTVs also use dual-clutch transmissions, often sharing oil between the engine, clutches and gearbox or using a dedicated transmission fluid. The vehicle maker’s manual lists which fluid type and viscosity apply.
Checking before you buy
Identify the exact transmission, then confirm the required fluid from the owner’s manual, a dealer parts lookup or service information. Check whether the unit has more than one fluid circuit and whether a filter is serviced at the same time.
Then compare that requirement with the current product data for any fluid you consider.
Frequently asked questions
Can I use ATF in a dual-clutch transmission?
Only if the manufacturer specifies it. Most DCTs call for their own fluid with friction properties matched to the clutches.
Does a dry-clutch DCT need fluid changes?
The clutches run dry, but the gearbox and controls use lubricants with their own service requirements. Check the maintenance schedule.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].