TH400 trans ....
If you have no forward gear take up in D, but have forward gear take up in L1 or L2...the Low roller clutch has failed....
Its a one way sprag race style item that works in conjunction with the Forward clutch pack to provide 1st gear...see pic below...the rollers and springs have collapsed...common problem...
Modulators control clutch pack application pressures...
Kick down solenoids control only kick down valves...
Governors control shift points
