Thank you for the reply and the information. I think the failure was due to higher loads imposed by racing. The car is a 65 Corvette that we have been running in vintage racing and the part that failed is the rear halfshaft which on the Corvette also functions as the upper "A" arm...
Most common driveshafts today (other than exotic lightweight shafts) are 1020 carbon steel welded to 1035 forged steel yokes which are adequate for strength in our application but we experienced a fatigue failure in the tube adjacent to the weld. What post weld heat treatment and or shot peening...
