1984 Corvette: Service Bulletin: Low Speed - "Chuggle"
Model Year: 1984 Corvettes with Automatic Transmission
Subject: Low Speed "Chuggle"
Source: Chevrolet Dealer Service Bulletin
Bulletin Number: 84-208, Section 6E, 7A (Vlt) (Vllc)
Date: October, 1984
TO: ALL CHEVROLET DEALERS
Some 1984 Corvettes may experience a low speed surge, which may be referred to as a "chuggle", and is usually noticeable at low engine speeds when the torque converter clutch is engaged.
Any 1984 Corvette with an automatic transmission experiencing this condition may be corrected with the installation of a new calibration PROM, P/N 1226938.
The new PROM calibration delays TCC engagement speed to 41 mph in fourth gear and disengagement speed 40 mph.