A little background: I bought a 2000 S70 cheap with a blown head gasket. The car had been sitting for about 6 months when I got it. I repaired the head gasket and started the engine. After checking that everything appeared OK with the engine, I jumped in to take it for a short test drive. It made it about a block when the tranny quit. I have spent the last couple of months trying to diagnose the problem in my spare time. The tranny would work for a few seconds when the car was first started and then quit. I could hear what I thought was the pump starving. We have all been under the impression that there is no filter in these FWD trannies...WRONG...there is a filter shown on the parts breakdown.
I have now replaced the tranny and the S70 is mobile. I took the old tranny apart just for fun. Yes, Virginia, there is a filter and it was completely plugged with crud. The filter is very small and the screen is very fine mesh...similar to the fuel pump screen. The most important realization was that the inlet of the filter is very, very close to the bottom of the case...maybe 1/8 inch away. The bottom of the cavity that the pump draws fluid from is completely flat. Any sludge that collects from material wearing off the clutches, dirt and general crud has nowhere to go. There is no recess for it to collect in so that the pump does not pick it up. So, in this case, the crud had settled in the bottom from the extended period of sitting. When I started the car, the pump picked up all the junk in the bottom, plugged the screen, the pump can't get any more fluid to pump...no fluid-no pressure...no pressure-no go!!!!!
HERE IS THE POINT! If you have not serviced your tranny, do it now. Pull the plug on the bottom of the tranny and drain the old fluid. Then follow the flush proceedures that have been discussed many times here. It's sad that the design of these units does not allow for crud to collect out of harms way. It is even more sad that the owners manual says that under normal conditions, there is no transmission service required! Thanks to Klaus and everyone else for all your input and suggestions. We need to understand that a few quarts of ATF can save a lot of expense and heartache.