What is the difference between dq380 and dq381?
2 Answers
The difference lies in the fact that dq381 can reduce engine wear and fuel consumption compared to dq380. Here are the detailed explanations: 1. In dq380, the oil pump gear is engaged with the clutch gear and is powered by the clutch. Therefore, whenever the clutch operates, the oil pump works, creating oil pressure. Under any circumstances, this consumes a portion of the engine's kinetic energy. In contrast, dq381's oil pump is not engaged with the clutch but has a dedicated power source. It operates only when oil pressure is needed and stops when not in use. This highlights the advantage of dq381, reducing the oil pump's consumption of the engine's kinetic energy. Theoretically, it also reduces emissions and achieves the goal of lowering fuel consumption. 2. Compared to dq380, dq381 has changes beyond just using higher viscosity ATF oil and optimizing friction for seals and bearings. The clutch module and the hydraulic system of the oil pump have also been modified. In the clutch module, the K1 return spring has been changed from a spiral type in dq380 to a diaphragm type. Hydraulically, an additional electric oil pump linked to the CAN bus has been added, controlled via valve adjustments. This supports the hydraulic circuit for clamping the clutch plates and operating the shift mechanism. The oil can also flow to the pressure circuit for lubricating and cooling the shafts, gears, and clutch plates. With the addition of the electric oil pump, the transmission can continue to supply oil to components during start-stop operation and coasting mode, unaffected by engine speed. It also improves the responsiveness of clutch re-engagement when the engine restarts.
We've seen a lot in transmission repairs, and despite the names DQ380 and DQ381 being just one digit apart, the actual differences are quite significant. The DQ381 is essentially an upgraded version of the DQ380, with Volkswagen making improvements in several key areas. The most noticeable change is the redesigned dual-mass flywheel, which significantly reduces idle vibration. The hydraulic control system has also been updated, particularly with more durable sealing rings in the oil circuit plate, greatly reducing the likelihood of oil leaks. Another upgrade is the new material formulation for the clutch friction plates, enhancing their resistance to burning and making them less prone to the old issues of slipping and shuddering. This is especially evident on long drives—the DQ381's temperature control is much better, its shift logic is smarter, and the low-speed follow-up jerkiness has been noticeably improved.
