K 1500 Yukon Denali AWD V8-6.0L VIN U (2002)
Seals and Gaskets: All Technical Service Bulletins
A/T - 4L60-E/4L65-E New Pump/Seal/Case/Service
Bulletin No.: 04-07-30-023
Date: May 12, 2004
INFORMATION
Subject:
Oil Pump Assembly Seal and Transmission Case Change
Models:
2002-2004 Cars and Light Duty Trucks
with 4L60-E or 4L65-E Automatic Transmissions (RPOs M30, M32 or M33)
An improved oil pump to case seal design has been made to the 4L60-E/4L65-E transmission. The new design affects the oil pump, the oil pump seal,
the transmission pan bolts and the transmission case. The complete design was implemented in three phases.
The first phase, beginning in September 2002, relocated the machining of the oil pump 0-ring seal groove in the pump body. The 0-ring seal groove
moved 1.6 mm (0.62 in) inward on the pump body in order to place the sealing surface deeper into the case bore. The relocated pump body groove can
be identified by measuring the groove location. Pump bodies that measure 2.3 mm (0.09 in) from the machined surface to the groove opening have the
relocated 0-ring seal groove. Pump bodies that measure 3.9 mm (0.15 in) are prior to September 2002 design.
