I have a 05 Tacoma DBL cab 4x4 with a 4.0 litre. Bought it new in June of 05. At first oil change it was changed over to Amsoil and have been running it ever since. The truck now has 41,000 miles and just recently changed differential and crank case oil over to Amsoil 75w 90 gear oil. Now it makes a vibration upon backing out of driveway and turning at the same time. It also happens when I take off out of my neighborhood for the first time but seems to be OK after that. Any suggestions?