A lot of other people will read these replies, just like you did on that other web site. That's why I included the story about the torque converter bolts. I said usually they make noise first implying that was not the problem in your case, but that might benefit someone else.
Transmission fluid IS hydraulic oil and it must be filtered. It is common to call it the transmission fluid oil filter.
The transmissions that use a solenoid pack are in the front-wheel-drive cars and minivans starting with the 1989 models. In the event of a total electrical or computer failure, the solenoids are spring-loaded to allow use of park, reverse, neutral, and second gears. The computer will also shut the system down when it detects a problem, and again, you have use of those gears. Those computer-controlled transmissions were not used in the trucks in 2000. You still have a version of the really tough 904 or 727 that was used in the '60s through the '80s, with an overdrive assembly added on. The place to start is by testing the main line pressure. If it is 0 psi, there could be a problem with the front pump or filter. If there is pressure, there could be a problem in the valve body, (not likely since the problem occurred while it was already in gear and moving), or something broke in the torque converter. It WOULD make sense to take it to a transmission specialist. They will be familiar with the transmission and any problem they find, they've seen it before.
Tuesday, December 7th, 2010 AT 6:34 PM