You have to go to a shop that does a "Road Force Balance". Go into Google and look up "Road Force". They use a balancer called the "Hunter GSP 9700". You can look that up also.
My Continental was having a "
wheel balance" problem. Took it back where I purchased the tires, and they tried twice, and both times, the tires were in balance. Took it to another place, and again, they said the tires were in balance. Found out about Road Force, and first I took it to my local Ford Dealer, who has the correct equipment, but all they did was to say, "yep, the tires are out of specs, 45lbs road force on one tire, 32 on another tire, etc. etc. (Yes, I was mad). Then on a trip up to Penfield, I went to Dunn Tire in Henrietta NY, and they did the Road Force correction correct.
The Hunter machine first spins tire slowly, with a roller pushing down on the tire. Then a lazer light shows the tech where to mark the tire. Then a bar pushes on the side of the
wheel, and again, a lazer light shows the tech where to mark the
wheel. Then the tire is deflated and moved so that both the marks line up. After tire is reinflated, it is then spin balanced. Dunn Tire did all four tires, then the machine told the tech which corner of the car to place each tire. Worked great for me. Since then, I've found a tire dealer here in Florida who has a Hunter GSM 9700 and says he knows how to use it.
Get a Road Force Balance. You won't be sorry.