4R Vibration More Info
Taken from researh.
Here is the problem. The wheels used on the 4Runner/Tacoma are “lug centric” and are not the more common “hub centric” wheels like on most cars and light trucks. Hub centric wheels are centered on the vehicle hubs using the center hole in the wheel. That is kind of simple. On lug centric wheels the wheels are centered on the vehicle hub using the lug bolt holes and not the center hole. When the wheels are made and machined they are done so using the lug holes to mount the wheels to the machines that make them. The lug holes are the true center of the wheel and not the center hole. So, if the center hole is not in the true center you can understand how mounting the wheel to the balance machine using the center hole is not going to work very well. The wheel needs to be mounted to the balance machine using the lugholes. This is done with a flange plate adapter made by Haweka.
The Haweka adapter firmly locks the wheel onto the balance machine in its true center. It holds wheel very solid and prevents movement. Toyota realized they had a problem with balancing these wheels and issued a Technical Service Bulletin (TSB SU002-96) requiring the Haweka adapter when balancing these wheels. The problem is that it seems that few Toyota dealers know about the TSB let alone have the adapter.
While on one of my many, many visits to the dealer to get the vibration fixed, I saw one of my tires on their balance machine. I walked over to it and grabbed the tire and shook it. It wobbled all over the place. I asked they guy how he thinks he can balance the tire with it moving around so much, “all the truck wheels do that.” That my friends, is the very center of the problem. If they cannot get the wheel to hold still on the shaft there is no way they can ever properly balance it. The Haweka adapter does two very basic things. First it mounts the wheel to the balance machine the same way it is mounted to your truck, and second it locks it to the shaft of the balance machine and prevents movement so you get a consistent and proper balance.
