my gearbox causes problems when switching or jerking when changing gears, especially between 3rd and 4th gears at about 50 – 60km/h. Motor D5 (XC90 AWD 2006 Vorfacelift), mileage 135,000km.. I don’t know what kind of gear is actually installed, but after a long reading of various forums (also from the USA etc.) I have compiled the following plan: 1. Change gear flush to TE 2. B4 Servo Cover (?) 3. Update for the gears however I would have a question to No. 2. and zw ar is written quite a lot about the B4 servo cover and that this cover very often solves such problems with the gearbox.. my on-board computer does not show me that a transmission maintenance is required.. moreover I have no problems with R gear or when starting.. only as described above during the city trip.. I also hear no noises.. so I think that I could solve my problem with the above 3 points.. Please now just for info where I can find this B4 servo co I can’t find it at Skandix, for example.. what’s the name of this thing in German? Is there even this B4 servo cover on my gearbox? If so, I would definitely have it changed, since it is supposed to cost only 25€