2016-2019 Toyota Tundra and Tacoma trucks feature plastic hole plugs in both sides of the frame to prevent water from entering the frame. One of the hole plug styles allows water to drain from the frame while still blocking water from entering.
This one-way drain plug is located near a usable frame lift point. If not careful when positioning the lift for frame contact, the drain plug may easily be crushed. If a plug is damaged, new plugs are available as P/N 90950-01A24 (2 per vehicle).