I did some more test driveng and I'm not so sure it is the converter. It will only shudder in overdrive. If i turn off overdrive and lock converter in third it is smooth as glass. Could it be antoher issue or is the converter really bad

 

it is the converter i would say. the low end torque in od is what causes the shudder. had the same thing right after i went to the 75hp injectors. very first thing i noticed after injector install was from 50 to 58 got this shudder. the xtra hp was too much for the converter. all other gears smooth as glass.

 

You say it has one year warranty, just send it back have it check. Also a valvebody or shift kit would help with alot of the issues. A convertor alone is not the answer you need more line presure make it all work better.

 

There is one name and one name only in the convertor world... That is Phil Taylor from Diesel Performance Convertors! And for trans its pretty simple too, its Goerend or Suncoast!