Do a search for P0740 to find my transmission diagnosis and removal thread. Sounds like the dealer got you for a bunch of stuff that was wrong, but that you probably wouldn't have cared much about-- valve cover gasket and power steering have nothing to do with your tranny code. The leaking solenoid pack was an unlikely cause for the code, though it doesn't hurt to fix. I think you should not go back to this dealer since they're either incompetent or just trying to line their pockets or both.
You likely do not "need" a new or rebuilt tranny. They'll tell you that the torque converter clutch material is in the fluid and likely contaminated the tranny. There was plenty of clutch material in my pan when I did a fluid/filter change after replacing the torque converter and I now have another 25,000 miles on the van with no trouble. A new/rebuilt torque converter and a fluid and filter change (not a flush) should do the trick. There is some reason to consider replacing the tranny since you're going to incur the expense of R&Ring it (mine was very low mileage at the time so I didn't bother with a replacement tranny), but you'll have to make the call whether that's worth it since you'll probably get at least another 20K to 30K out of this tranny if it has been reasonably taken care of. Given the van's value, I doubt a replacement is worth it.
If you skim through my thread you'll see that I did the R&R myself with the help and advice of a professional mechanic here on the site. He said he could have done it for about $500, so if you live near him, go to him, if not call around to some independent shops. If you find someone familiar enough with the van, it shouldn't cost you too much to just R&R the torque converter and do a pan-drop fluid and filter change.
2003 Durango SLT
Mods: Remote Start
Just got a new set of BFG All-Terrains
Planning retrofit to 4WABS
1999 Durango SLT+
Mods: B&M Supercooler, Ford OEM Remote Start/Keyless Entry/Alarm, Heated Seats
01 T&C Limited 3.8l
Last edited by Rick99; 01-15-2010 at 08:59 AM.