A/T - Whine From Rear of Transmission
TECHNICALBulletin No.: 08-07-30-032
Date: June 26, 2008
Subject:
Whine Noise from Rear of Transmission (Replace Transmission Case Extension)
Models:
2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe (2WD Only)
2008 GMC Sierra, Yukon, Yukon XL (2WD Only)
with 4L60E or 4L70E Automatic Transmission (RPO M30 or M70)
Condition
Some customers may comment on a whine noise coming from the rear of the transmission. This noise may be most likely to occur in the 24-56 km/h (15-35 mph) range.
Cause
This noise may be caused by contact between the transmission speed sensor and the speed sensor rotor.
Correction
To diagnose this condition, shim the speed sensor away from the extension housing and drive the vehicle. If the noise is no longer present, the speed sensor was contacting the rotor and the extension assembly should be replaced. If the noise is still present after shimming, refer to Symptoms Automatic Transmission in SI for further diagnostic information.
Parts Information
Warranty Information
For vehicles repaired under warranty, use the table.
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