Some 2017-2019 Toyota Tacoma trucks equipped with the BD20 differential (non-TRD) may exhibit a noise or vibration from the rear of the vehicle at low speeds or while braking. This condition may be caused by excessive clearance between the brake drum and axle drum flange.
Inspect the rear drum and brake assembly for any signs of defects or wear. Remedy any noticeable defects or wear prior to proceeding and re-test. If vibration and/or noise is still present, inspect the rear axle flange for corrosion/rust buildup. Clean as needed with a wire brush.
Measure the diameter of the axle flange. Using a digital or dial caliper, measure the axle flange boss diameter. Take measurements in three locations around the flange to verify the diameter.
Flange diameter specification is 4.252 – 4.250-inch (108.000 – 107.946mm). If out of specification, replace the axle. Test drive the vehicle to confirm that the noise/vibration is no longer present.