Different specifications of A4LD valve body parts.
I came across something interesting the other day. Maybe somebody in this forum could possibly answer these questions. They are all related to the A4LD valve body. (1) In the new book (volume 6) from Sonnax.Com, on page 96, list different boost valve repair kits. It says that the 2.3, 2.8, 2.9, and 3.0 use a low ratio boost valve, and the 4.0 uses a high ratio boost valve? Does this really make a big difference depending upon the type of engine it's going onto? Wouldn't it be better to just use a high ratio boost valve to get a more responsive shift? Could that be used even on the valve bodies with the smaller engines? Another question is on the 4 different sizes of valve body balls. (2) What determines the specifications on which size to choose? By the way, that book from Sonnax came with the October issue of Gears magazine. This magazine has a lot of very useful articles on all kinds of transmissions, with stories about repairs, and updates. (3) The A4LD rebuild diary from Glacier991 list different locations for the valve body balls depending upon the engine type. He shows a page from a repair manual in his thread with a comparison of different engines, and where the check balls are supposed to be located. Why would it be necessary to rearrange the valve body balls for different size engines? (4) I guess all of these modifications change the way the shift pattern performs on that type of engine, since the bigger the engine, the more horsepower, and torque it will develop at a lower RPM range. If this is the case, then how would one of these A4LD transmissions perform if it were designed for a specific engine, and used on another engine? Would the performance, and shift pattern change dramatically, or be unnoticeable? Maybe this is one of the tricks of the valve body reprogramming kits. It improves fluid circulation, and therefore improves on the shift.