My high mileage (226K) '98 XLT SOHC 4wd now won't shift at all following a fluid change - can anybody recommend threads that I should check? I've studied the 5R55E VB rebuild diary (since it looks like that might be in my future). And I've found several threads warning me to not do what I've done. So far this has been the most helpful thread: http://www.explorerforum.com/forums/showthread.php?t=121812&highlight=shift+flush with a good suggestion about checking the O-rings on the filter. Anybody know of any other threads I should check out? Here's more than you want to know: This was not a flush, but a dialysis (what's the correct name for this method?) where you disconnect the return line at the output of the cooler and pump out old fluid and refill new fluid 1 quart at a time. The sequence was: I did a pan drop, filter change, added drain valve to the pan, then reassemble and refill. Test drive was fine, shifting seemed to work exactly as before. Get back and go to check level again - notice smoke coming from under the car. Drop down and see the catalytic converter smoking pretty good - ok that makes sense, I dropped alot of oil on it getting the pan out. So maybe it just needs time to burn it off. So far so good. The next day I tempted the fates and did what some have recommended against: a fluid exchange. Disconnected the cooler return line, plugged the line back to the transmission and collected the output in a graduated milk jug. Start up, put a quart in the jug, shut down, add a quart repeat. The fluid looked pretty good by the 6th quart (remember that I'd put in 4 new quarts the day before after the pan drop) but I did a total of 9 quarts since I had them. Reconnected, started up, ran through the gears, warmed up, checked fluid level. Fluid level might have been a little high, like maybe 1/2 a quart or so. No sign of any leakage. Test drive. Uh oh. Long pause when shifting into reverse. Long pause when shifting into drive. Slipping then flare between 1 and 2. Some hunting. Drive around the block a couple of times. Things maybe getting a little better. Pull back in the driveway and check level, maybe a little low. No sign of any leakage. Top it off. Next morning: Same as the day before. No signs of leakage under the truck, cold level looks good. Long pause shifting into reverse, another long pause shifting into drive. Drive around the block a couple of times. Things may be getting a little better as it warms up. Park it. Go back later in the day, recheck levels - maybe a little high. Start up, warm up check levels, maybe a little low (hard to tell since the new oil is about transparent on the dipstick). Try to drive - no shift. Reverse, Drive, first or second same story. Here's my game plan - let me know if you see a better strategy: 1. Verify that the shift linkage is connected. I didn't do anything with the linkage so there's no reason it should be disconnected, but it's easy to check. 2. Verify flow out of the cooler. It was flowing nicely for the dialysis, but maybe it's not flowing now? Easy to check. 3. Chip out the rusted/frozen/seized bolts on the catalytic converter. On this X you can't get the pan out without removing the catalytic converter or disconnecting the forward drive shaft. I couldn't get the catalytic converter disconnected the other day so I disconnected the forward drive shaft which isn't as bad as it sounds. But getting the catalytic converter out of the way will make the next step easier. And I may have a long future of peering into the transmission ahead so go ahead and get this done. 4. Redo the pan drop and filter change. Hope that the problem is an issue with the filter O-rings. Check the torque on the VB bolts while I'm there? Carefully check its gasket while I'm there? 5. If that doesn't work then what? Would Autozone have a transmission pressure tester that I could use to verify the pump was actually working? Dive right in to a VB rebuild and EPC replace? Admit my sins (and limitations) and have it towed to a transmission shop? I was living on borrowed time with 225K miles on what I think is the original transmission (I've had it since 100K). I thought long and hard about the fluid change knowing that this outcome was a real possibility. In the end I was swayed by the argument: if changing the fluids is going to kill your transmission then it's gonna die soon anyway, so let's get on with the program. Probably changing my tune now... I'm a rookie at this stuff - my skill levels are at the low end but getting better thanks to all the great articles in this forum. Thanks in advance.