Sierra 1500 4WD V8-6.0L (2007)
Fluid Pan: Service and Repair
Allison - Automatic Transmission
Oil Pan Replacement
Removal Procedure
1. Raise the vehicle. Refer to Vehicle Lifting.
Important: It would be helpful to record the amount of transmission fluid lost during this procedure. Fluid in good condition, drained
into a clean container, may be reused.
2. Remove the drain plug (7) and drain plug seal (6) from the oil pan (5). Allow the fluid to drain into a suitable container.
3. Inspect the drained fluid.
4. Remove 12 bolts (8). Hold the oil pan in position as the last bolt is removed.
5. Remove oil pan (5) and gasket (3).
6. Inspect magnet (4). Excessive metallic particles or large metallic particles may indicate need for overhaul or replacement of the transmission.
Important: DO NOT remove the transmission internal oil filter or seal if only replacing the oil pan or oil pan gasket.
7. Remove the transmission internal oil filter (2) by pulling straight down where the suction tube is seated in the transmission case.
8. Remove the transmission internal oil filter seal (1) from the filter or from the seal bore in the transmission case. Discard the old seal. Discard the
filter, if the filter is being replaced.
Installation Procedure
1. Remove all gasket material from the transmission case. Remove any scratches from the transmission case that would cause a split-line leak.
2. Place a new seal (1) on the tube of the transmission internal oil filter (2), if the filter was removed. Be sure the seal locates against the shoulder on
the internal oil filter tube.
3. Push the filter (2) and seal (1) into the seal bore in the transmission case. Position the transmission internal oil filter properly.
4. Install 2 headless guide bolts (9), M8 x 1.25, into opposite corners of the oil pan mounting face on the transmission case.
5. Place a gasket (3) on the oil pan and align the bolt holes.
6. Slide the gasket (3) and oil pan (5) over the guide bolts and hold them in place while installing 2 bolts (8) to hold the parts in place.
Notice: Refer to Fastener Notice.
7. Remove the guide bolts.
8. Install the 10 remaining oil pan bolts (8).
Tighten the bolts to 27 N.m (20 lb ft).
