I have a 2000 4runner SR5/v6/auto that has seemed to develop a rear end problem. Vehicle has 140K miles and has never towed or off road. Last time it was serviced, about 6 mos ago, Toyota mechanic said he found a good amount of metal shavings in rear end fluid and asked me if I was experiencing any problems. At the time I wasn't. Now, particularly noticeable if the car is started after sitting overnight, and put in reverse or drive, it takes a couple of seconds before it will move. It almost feels like the emergency brake is on. Then it releases and moves. Once it is going, it seems fine. Don't hear any weird noises. Anyone experience this?