Got my jeep back from dealer they installed a new steering dampner took it for a drive the steering wheel still shakes service rep came for a drive and said it might be a universal joint in the front so they are going to check it again monday

 

What did I miss? What was wrong?

 

The dealers rebalanced all four tires and it doesnt shake anymore he said one was off by.50 and the other .75 witch seems quite minimale,he then told me it was either that or the mechanic lied the when he put on my spacers and did not removed the retention clips and then took them off when he rebalanced my tires