I'm told the 4R100 torque converter has a high failure rate. Has anyone experienced a failure and if so, how does it fail? After failure, does the tranmission need to be rebuilt or can you just replace the Torque Converter? Thanks!

 

There are several different 4r100 torque converters. The pre-2001 units are prone to failure. They had a twin disc system and the lockup piston beats against the front cover.
All of them until 2003 had plastic stator caps which were prone to failure as well. They replaced it with a bearing and ballooning seems to be the weakest link now.
Alan

 

When the failures you mention occur, what is the symptom? Check engine light, flashing O/D light, no gears, noise, no O/D, etc.

 

As with most any converter failure, transmission contamination is the result.
Alan