Denny
Read your comments about bias ply tires being inferior today than in the past. Could be. I had Cooper bias 650-16 on the 49 for years and as they got older, harder and probably worn out in the belting, my ride shook at 40 mph exactly.
I changed for Firestone bias ply. I have never been happier with a set of tires. My ride is smoother and there is no 'good morning' bump.
However in this case Rick may have problems with his tires but I am inclined to think maybe something in the drive shaft or bushing.
