I need to replace my rear transmission seal on my 99 35th anniv. GT. It has a 4.6L with a 5-speed. My Ford dealer is having a hard time with this. The first seal they ordered wasn't as big in diameter. I took it back and then they gave me a seal that looked like a large washer. I knew this wasn't right. I tried one from a automatic tranny, but the shaft wouldn't go through the center. I'm pretty sure the diameter was going to work as far as putting into the tranny. Can someone help me with this problem. My Ford dealer has a call into Ford Motors, but I don't know how long that is going to take.