Engine Controls - Chuggle or Surge When TCC Engaged
Number: 86-100Section: 6E
Date: June 1986
Subject: PROM CHANGE - TO REVISE TCC ENGAGEMENT
Model and Year: 1985-86 CELEBRITY MODELS WITH LR8 2.5L L4 ENGINES (VIN CODE R) MD9 3-SPEED AUTOMATIC TRANSMISSION AND F17 (2.84 RATIO) OR F62 (2.39 RATIO) TRANSAXLE
TO: ALL CHEVROLET DEALERS
Customer comments of "chuggle" or "surge" may be received on 1985-86 Celebrity models with 2.5L L4 engines when the torque converter clutch (TCC) engages at lower vehicle speeds.
This condition will be improved by the installation of a new service PROM. These service PROMS contain calibration changes designed to enhance vehicle driveability. The TCC engagement speed will be raised to 49 mph. Service PROM applications are listed below:
PROM P/N APPLICATION
1228020 1985 Celebrity with 2.84 axle
1227924 1985 Celebrity with 2.39 axle
1228019 1986 Celebrity with 2.84 axle
1228018 1986 Celebrity with 2.39 axle
Use applicable Labor Time and Operation numbers.