Transmissions · 6 min read
Understanding Automatic Transmission Types: AT, CVT and DCT
How conventional automatics, CVTs and dual-clutch transmissions differ, and why the transmission model code matters when ordering.
"Automatic transmission" covers several very different designs. Knowing which type a vehicle uses helps you order the correct assembly or internal parts.
Conventional automatic (AT)
Uses a torque converter and planetary gear sets, with clutch packs and bands applied hydraulically through a valve body. Examples include 4-speed units such as the 4F27E and 01N and 6-speed units such as the 6F24 and 09G (TF-60SN). Common service parts: friction and steel plates, pistons, solenoids and filters.
Continuously variable transmission (CVT)
Instead of fixed gears, a CVT uses two variable-diameter pulleys connected by a steel belt or chain, giving a continuous range of ratios. JF011E (RE0F10A) and JF017E are widely used CVT families. Key wear parts include the chain belt and valve body components.
Dual-clutch transmission (DCT / DSG)
A DCT uses two clutches — one for odd and one for even gears — for fast shifts. Dry-clutch units such as the 7-speed DQ200 (0AM) suit smaller engines; wet-clutch units like the DL501 (0B5) handle higher torque.
Why the model code matters
Within each type, the transmission model code, plus drive configuration (2WD/4WD) and engine size, determines which assembly or kit fits. Always include the code from the transmission tag or the vehicle's parts catalog in your inquiry.