A rebuilt transmission was put in last year. Also put on new tires. What is the most likely culprit? Out of balance tires? U Joints? Something else I'm missing?
What engine? 2WD or 4WD? How long before transmission replacement did symptom start?
5.3 V8 4WD The noise just started, a year after the transmission was rebuilt and had new tires put on. Probably 3000 miles ago
Probably unrelated to either of those items. Sounds like drive-train like you mentioned, U-joints or driveshaft , would be my thought also. Is it easy to duplicate? Maybe test drive with a mechanic & get 2nd opinion.