Understood. I don't know where my trouble is so I will need to tear down the c-Diff and transmission. I also had some clicking under power so I may have a main diff issue as well.

I think that many people have undercalled the effects of the c-Diff. I started with 5 pins for a medium grip track. It made a huge difference to me. I was able to control the pitch of the vehicle in the air. Great balance of power and no slipping so I was able to drive the car more like my 8th scale than a 2wd buggy!

Great design Marcus. By far the best upgrade I have experienced so far.