CAN ANYBODY TELL ME ABOUT TORQUE CONVERTER SHUTTER

Sounds like your transmission is actually slipping in fourth gear instead of torque converter shudder. Scan your vehicle and see if you come up with a "Incorrect gear ratio" (PO730) code which would comfirm slipping in your transmission.

Could be caused by worn Lock-up clutch, dirty or restricted fluid flow, worn valve body, or even an engine that is not properly tuned.