S10/T10 P/U 2WD V6-262 4.3L VIN W CPI (1992)
Torque Converter: Customer Interest
A/T - Vibration/Rattle, Torque Converter Clutch Applied
Number: 93-38-7A
Section: 7A
Date: OCT. 1992
Corporate Bulletin No.: 277145
ASE No.: A2
Subject:
DRIVELINE VIBRATION AND/OR GEAR RATTLE WITH TORQUE CONVERTER CLUTCH (TCC) APPLIED
Model and Year:
1992-93 S/T TRUCKS WITH 4.3L (L35) ENGINE AND 4L60 OR 4L60-E AUTOMATIC TRANSMISSION
TRANSMISSION APPLICATIONS:
1992 HYDRA-MATIC 4L60 (MD8)
1993 HYDRA-MATIC 4L60-E (M30)
TRANSMISSION MODELS:
2TAM, 2TBM, 3TAD, 3TBD
SUBJECT:
Driveline Vibration and/or Gear
Rattle with TCC Applied
VEHICLE APPLICATIONS:
S/T Trucks with L35
Condition:
Some 1992-1993 S and T trucks equipped with 4.3 liter (L35) engine and the HYDRA-MATIC 4L60 or 4L60-E transmission built before Julian Date
223 (August 10, 1992) may exhibit a rattle or driveline vibration with the torque converter clutch (TCC) applied at low engine speeds (1000-2000 RPM).
Cause:
The rattle or driveline vibration may be due to the stiffness of the spring rate of the damper springs in the torque converter.
Correction:
Install a new torque converter assembly which corrects the rattle in the 1000-2000 RPM operating range.
Diagnosis Information:
The rattle or driveline vibration condition only occurs in fourth gear with TCC applied. Use the following procedure to determine if the vehicle has this
condition:
1.
Accelerate the vehicle to achieve fourth gear and confirm that TCC is applied.
2.
Maintain low engine speed (1000-2000 RPM) then crowd the throttle to above 25 percent TPS to induce the rattle or drive line vibration.
NOTE:
Excessive throttle input will disengage the TCC. Applying the brake will also disengage the TCC.
Service Parts Information:
Part Name
Part Number
Torque Converter Assembly (DBAF)
8688904
Parts are currently available from GMSPO.