Rainier AWD L6-4.2L VIN S (2005)
Differential Case: All Technical Service Bulletins
Engine/Drivetrain - Front End Oil Leaks
Bulletin No.: 04-04-19-002
Date: November 18, 2004
TECHNICAL
Subject:
Lubricant/Oil Leak From Front Area of Vehicle (Install Washer/Shim Between Oil Pan and Front Axle Housing Assembly)
Models:
2004-2005 Buick Rainier
2004-2005 Chevrolet TrailBlazer, TrailBlazer EXT
2004-2005 GMC Envoy, Envoy XL, Envoy XUV
with 4.2L L6 Engine (VIN S - RPO LL8) and Four Wheel or All Wheel Drive
Condition
Some customers may comment on an oil leak from the front area of the vehicle.
Diagnosis may show the area of concern is at the axle case/housing half sealing surface adjacent to the pinion seal.
Cause
The front axle case/housing and the engine oil pan are mounted to each other on these vehicles. Casting variations in both the oil pan and the axle
case/housing may cause hard contact between these two items where contact is not intended. When this happens, the front axle case/housing may distort
when tightened to the oil pan. This may cause a leak path between the front axle case halves.
Correction
Follow the service procedure below to repair this condition.
1.
Raise and support the vehicle.
2.
Diagnose the source of the leak.
^
If the source of the leak is something other than the case/housing half sealing surface, continue with the appropriate SI procedure to repair the
leak source.
^
If the source of the leak is the case/housing halves, continue with the next step.
Important:
Observe the position of all the driveline components. Accurately mark the relationship of the components before removal. These components
include the propeller shafts, the drive axles, the pinion flanges, and the output shafts. Reassemble all components in the exact relationship to
each other as they were before removal. Follow the specifications, the torque values, and any measurements obtained prior to disassembly.
3.
Reference mark the relationship of the propeller shaft to the front axle pinion yoke.
4.
Remove the yoke retainer bolts and yoke retainers from the front axle pinion yoke.
Note:
When removing the propeller shaft, do not attempt to remove the shaft by pounding on the yoke ears or using a tool between the yoke and the
universal joint. If the propeller shaft is removed by using such means, the injection joints may fracture and lead to premature failure of the
joint.
5.
Disconnect the propeller shaft from the front axle pinon yoke. Wrap the bearing caps with tape in order to prevent the loss of bearing rollers.
6.
Position the front of the driveshaft so that the rear most front axle case/housing bolt can be removed.
7.
Remove the rear most front axle case/housing to oil pan bolt. Upon removal of the bolt, a gap my appear between the front axle case/housing and
the oil pan. This may indicate a interference condition between the front axle case/housing and the oil pan.
