Before or after overhaul, vehicles equipped with the 09M/09G/TF60-SN transmission may exhibit a complaint of harsh reverse, third and fifth gears when hot.
The cause may be a worn bonded balance piston in the K3-clutch drum. See the cross-sectional view in Figure 1.
The balance-piston function is to hold “counter” or “back” pressure on the K3 apply piston. The balance piston is fed from the lube circuit, and its purpose is to provide a small amount of pressure to assist the release of the K3 clutch. It also acts as an accumulator during application of the K3 clutch (figures 2 and 3). The bonded piston has three notches where the retaining snap ring is situated, allowing a controlled leak of this pressure, and when the bonded rubber is worn this will allow a larger volume of pressure loss, which can cause the harsh applications.
Refer to Figure 4 and replace the bonded K3 balance piston.
Note: At the time of this printing, after-market replacement pistons should be available. Dealers sell parts for this transmission only as an assembly.
After overhaul, vehicles equipped with the 09A (JF506E) may exhibit a 2-3 flare and a harsh application into fourth. On vehicles equipped with the 09G (TF60-SN) the complaint may be a double bump on the 2-3 and/or downshift clunks.
The cause may be that the clutch adaptives were not reset.
Using a capable scan tool go into the engine side and reset all the adapts. The following six steps in figures 5 through 10 will show how to reset the adaptives through the laptop-based VAG-Com diagnostic system.
Figures 11 through 13 describe each of the data blocks available in this system.
It will be necessary to take a 15-shift-cycle road test after performing this reset to fine-tune the adapts.
Note: Early-model 09As require a capable scan tool to reset adapts. You cannot drive them out! ATSG highly recommends resetting adapts on all the above-mentioned vehicles.
November 2010 Issue
Volume 27, No. 11
- Audi/VW 09M/09G/TF60-SN: Harsh shifts into reverse, third and fifth gears
- VW 09A & 09G: 2-3 flare, harsh 3-4; double-bump 2-3 and/or downshift clunks