* 4L60E 4-speed automatic transmission: This was the standard transmission for most trim levels.
* 4L80E 4-speed automatic transmission: This was offered as an option for higher trim levels and heavy-duty towing packages.
It's important to note that the specific transmission in a 2005 Tahoe will depend on the exact model and trim level. The best way to know for sure is to check the Vehicle Identification Number (VIN) or consult the owner's manual.