The General Motors 4L30E we have is at best generic. It was anything special for the VX and was old tech and weak. It was never designed for 4WD all the time for certain. I been running now for half a decade on my rebuild I guess or getting close, glad all is well. The old man who just did the actualy tranny work ( not the wrencher who took the unit out of my car) had about 40 years in doing trannys. I think he could have done it with his eyes closed, reassembling 100's of parts and I have flawless performance now but I don't push hard anymore. We got lots of people on this forum since me with total failure of their trannys like I predicted! We all will have to rebuild!