Sierra 1500 4WD V8-6.0L (2007)
Seals and Gaskets: All Technical Service Bulletins
A/T - Fluid Leak From Bell Housing Area
TECHNICAL
Bulletin No.: 08-07-30-023
Date: May 08, 2008
Subject:
4L60-E/4L65-E/4L70‐E Automatic Transmission Fluid Leak from Oil Pump or Bell Housing Area (Replace Torque Converter Hub-to-Oil
Pump Seal Assembly)
Models:
2007-2008 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe, TrailBlazer
2007-2008 GMC Envoy, Savana, Sierra, Yukon, Yukon XL
2007-2008 HUMMER H2
2007-2008 Saab 9-7X
with 4L60-E, 4L65-E or 4L70‐E Automatic Transmission (RPOs M30, M32 or M70) and 4.8L, 5.3L or 6.0L V8 Engine
Attention:
This bulletin applies to vehicles built prior to December 2007.
Condition
Some customers may comment on an automatic transmission fluid leak. Upon further investigation, the technician may find fluid leaking from the oil
pump or bell housing area.
Cause
Investigation of 2007 transmissions has shown wear of the torque converter hub-to-pump seal (243, illustrated in the Oil Pump Disassembled View in
SI).
Correction
Verify that the leak is coming from the oil pump or bell housing area by the use of oil dye in the transmission. Refer to Fluid Leak Diagnosis in SI. Clean
the transmission suspected area of all residual oil and drive the vehicle to see if the dye begins to appear. If the leak is coming from the bell housing
replace the torque converter seal.
Parts Information
Warranty Information (excluding Saab U.S. Models)
For vehicles repaired under warranty, use the table.
Warranty Information (Saab U.S. Models)
For vehicles repaired under warranty, use the table.
