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Driveline - Vibration/Growl Noise

File In Section: 07 - Transmission/Transaxle

Bulletin No.: 99-07-30-024

Date: October, 1999

TECHNICAL

Subject:
Driveline Vibration/Growl Noise (Reprogram PCM)

Models:
2000 Chevrolet and GMC C/K Utility and Pickup Models (Silverado and Sierra)
with 4.8 L or 5.3 L Engine (VINs V, T - RPOs LR4, LM7)
and Hydra-Matic 4L60-E Transmission (RPO M30)

Condition

Some customers may comment about a driveline vibration/growl noise at speeds between 56-80 km/h (35-50 mph) with low engine speeds.

Cause

Engine torsional vibration when the torque converter clutch is engaged at low engine speeds, 1100-1400 RPM, can excite various driveline components. These driveline disturbances can cause noises and vibrations that the driver may feel and/or hear.

Correction

Reprogram the Powenrain Control Module (PCM) with the calibrations listed in this bulletin.

Parts Information





The calibrations listed are electronic calibrations and are NOT available from GMSPO. Calibrations will be available from Techline starting October 1999, on the TIS 2000 Disc 21 CD ROM or Techlme CD ROM # 20/21.

Warranty Information

For vehicles repaired under warranty, use:

Labor
Operation Description Labor Time

Use
Published
J6355 PROM Reprogramming Labor
Operation
Time