I did some searches and never found the answer. I have a 2006 4.0 4runner and decided to keep it. With 36,000 miles it is as good as new EXCEPT! I would like to go full synthetics on Trans, Trans case, axels and motor. While at Toyota service dept. I was told that they would do the motor, trans case and axels but after checking my vin and under the hood, the service writer says I have the World Standard fluid already in it and it is synthetic and not recommended for any change until 100,000. I have never heard of this, have you?