Gear Ratios on TDU PE 2.77

[HeLeX]

Every time I load a car an change the final drive say from 4.05 to 3.55 I notice that it doesn't make one differece to the gears at all. Usually lowering the final drive is supposed to increase gear range on all gears but it never does this at all. If I change one gear individually it totally stuffs up and like it will have 5 gears from 0-150km/h and then 6th gear will go to like 300km/h. What is happening?

[TDUFREAK500]

Thats because changing final drive only affects Gear ratios in TDUMT in TDUPE you need to change the gear ratios as well but you need to adjust them evenly so that they aren't out of wack