Bulletin #203 Transmission Type: 4T60E Date: 12-97 Topic: TCC Applies with 2nd gear 4T60-E (93 and later only) TCC Applies with 2nd gear A common customer complaint on 93 and later 4T60-E's has been "TCC applies with the 1-2 shift" even without a command from the ECM. Currently the most common cause has been a broken TCC Orifice Tube and Screen assembly. When the TCC Orifice breaks oil will flow unrestricted to the TCC solenoid causing lock-up to occur right with, or shortly after, the 1-2 shift. In addition to this complaint, "chugs or shudders while stopping", and "no TCC release with the brake" are also common complaints. The TCC orifice should be replaced with the revised part number listed below. In addition to replacing the orifice, it is recommended the hole in the spacer plate be resized as shown below. On many units that have had this problem, it has been noted that the orifice tube does not fit tightly into the plate. At this time it is suspected that the orifice is spinning in the plate causing the orifice to break or, be cut in half. Early model hydraulics did not use a TCC orifice. See Bulletin #172 for TCC orifice tube application information. New TCC Orifice Tube (Updated Material)...GM Part # 24203263 Place this area of the plate over a sprag race. Put a steel check ball on the hole and hit it a few times with a small hammer. Flip the plate over and repeat 2 or 3 times. Redrill the hole to .128". Install the new TCC oricice tube and o-ring into the resized hole. It should "snap" into the plate and be held in tightly to prevent it from spinning and breaking again. COPYRIGHT© 1997/PAUL YAKLIN/ATC