Getting more and more acquainted with the "new" 850 TDI with the AW50-42 automatic transaxle, about 210.000 km driven, I realize that there is hard shifting from gear 3 to 4 while the other shifts seem to happen much more smoothly. There is a sort of rumbling through the car especially if I accelerate heavily while the shift from 3 to 4 happens. I got the impression from some written source that the torque converter lock-up may engage in any gear, my impression is, that it engages only in 4th gear. Before buying the car I had it checked, the OBDII did not contain any fault code from the gear box. According to Volvo service plan the previous owner never had the oil changed. That is what I will have done next. Could it have influence on shifting mechanics? Experts on automatic gear boxes are rare here in central Europe, manually shifted gear boxes are predominant.
Any idea about causes of hard shifting only from 3 to 4?
Regards
Viktor, Vienna, Austria, Europe
The e-mail in the header is never read personal e-mail vikwei at gmx dot at