First of all, thank you for the information in this forum and here is an example of the change of original diff for TT-02 into front one-way diff and rear solid axle.
Also, here is the change of original rear diff to CS solid diff. With this change for AWD TT-02 series, this makes the rear wheels to run faster than the front wheels. The speed ratio could be changed in accordance to different options of bevel gears.
Thank you for visiting ^_^