Buying Used Cars with Direct Shift Gearboxes (DSGs)
Direct Shift Gearboxes (DSGs), found in VW, Audi and Skoda vehicles, are commonly known as DSG transmissions. They are the new generation of electronically controlled, dual clutch multiple-shaft gearboxes in a transaxle design. These gearboxes are classed as an automatic transmission in operation, but can be operated in semi-manual modes. In basic terms, DSG’s automates two separate manual gearboxes (and clutches) contained within one trans housing, which work together as one unit. By using two independent clutches, a DSG can operate and achieve faster shift rates and eliminate the requirement for a torque convertor.
How do DSGs work?
In principle, the transmission operates two clutch packs; the outer clutch pack plays the role of operating gears 1,3, 5 and 7 when fitted and reversed. The outer clutch also is of a larger diameter compared to the inner diameter, and can therefore handle heavier loads. The inner clutch pack drives gears 2,4 and 6. The way this transmission operates is through both 1st and 2nd gears loading from a stationary position. The clutch then engages the odd gear shafts and the clutch vehicle starts out. When it is time to change gears, the transmission simply uses the clutches to switch from the odd to the even shaft in order to reach 2nd gear. This sequencing runs right through the range to 6th or 7th gear, depending on the model.
Things to look out for
With this style of transmission on a test drive are:
- A shudder on acceleration from a stop start
- Disengagement in reverse on hills
- Check lights on the dash cluster, indicating a possible computer malfunction
In our transmission workshop, we are seeing an ever increasing number of these units coming in with computer hydraulic failures and clutch fork guides in the manual side of the transmission braking. This can give you disengagement when accelerating.
I hope that this short article gave you a better understanding of DSG’s, as well as what to look for if considering buying a second hand vehicle. Always remember, a small check now could save a larger cheque later!
From Peter Duncan and the team at Cronulla Sutherland Automatics.
Our Transmissions Services Include:
- Automatic transmission overhauls
- Repairs / servicing
- Coolers supplied & installed
- Shift Kit installations
- Reconditioned torque converters
- Valve Body reconditioning
- General servicing
- Clutch replacement & flywheel machining
- Differential servicing
- Fault Diagnosis & Troubleshooting
- Gearbox repair
- Clutch recalibration
- Transfer box overhauls
- Coolant changes / flushing
- All Australian & imported vehicles
- FWD & 4WD
- Electronic controlled
- Torque converter repairs & overhauls
- General auto warranty servicing
- Authorised registration inspection (Pink slip)