I have had FJ since 2007. Two years ago, after about 110,000, differential went out. About 20,000 miles after replacement, it started to vibrate on incline as you accelerate, or after pressing gas and coasting, and then gas again, car vibrates. Initially thought that I was going over a rough road. If I punch the gas, then vibration goes away. Any idea what the problem is? I am afraid to take it to dealer, fearing it might cost a lot of money to dianose and repair. I'd appreciate any help I can get.