When replacing the Lower Case Extension (LCE) (Fig. 12) on 2019-2025 Silverado 1500, Sierra 1500; 2020-2025 CT4; 2023-2024 Colorado and Canyon models equipped with the 2.7L engine (RPO L2R, L3B), it also must be determined if a plastic or aluminum oil pan should be used.
The lower structural extension of the 2.7L engine block houses the oil pump and balance shafts.
Fig. 12
To validate the correct LCE, locate the Part Unit Number (PUN) code on the side of the LCE. (Fig. 13)
Fig. 13
Replacing the Oil Pan
If the oil pan is being replaced, verify the size of the LCE oil flow check valve hole diameter to determine the proper service repairs.
If the hole diameter is 15.0 mm (Fig. 14, #1), use the plastic oil pan. If the hole diameter is 22.7 mm (Fig. 14, #2), install a check valve and an aluminum oil pan.
Fig. 14
If the LCE is being replaced, install the LCE with the larger check valve hole diameter (22.7 mm), a check valve, and aluminum oil pan.
For more information, including part numbers, refer to Bulletin #24-NA-247.
Thanks to Scott Willems
