03 5R55E TC not locking up?

[Fordtruckman80]

For as long as i've had my 03 Ranger (3.0,5R55E), it's had a weird shutter whenever I apply throttle to the truck in reverse. I usually just let the truck coast under it's own power, so it never really bothered me. But any time the truck is in reverse, the idle hangs around 500-600. Well about a month ago I had to take my truck through about 2-3 feet of mud to reach one of the barns at work. After I got off of work I got onto the highway, and noticed my truck started to idle strange. Having had problems with my original IAC before, and noticing the same symptoms, I went to Autozone and swapped IAC's thinking the one I had bought from there had failed. Well that seemed to fix the idle, but then my truck developed the same shutter reverse has had whenever I put the truck in Drive as well. It also seems to bog down whenever I try to accelerate from a dead stop. But it only does this whenever I apply medium to heavy throttle. If I apply light throttle, then it isn't a problem. Now here's the kicker. This problems only happens when the truck warms up. When it hasn't been run in a few hours, there are absolutely no problems. There is also no O/D Off light currently. However, the light used to come on whenever I would hit about 45-50 mph. It seemed to happen whenever the truck would start shaking. I still had the original tires on the truck, so I figured the tires had a few broken belts, were shaking the truck, which were in turn shaking something around in the trans. I got new tires for the truck, and I haven't seen the O/D Off light since. However I did have the code read and it came back as a TCC circuit malfunction or stuck off, IIRC. I can't remember the exact P-designation. Now, somebody suggested to me that my shudder in reverse and drive sounds like the TC is not unlocking. So today while on the highway going about 65 mph, I let off the gas to see if the TC still locks up. However, the rpms dropped down to 2,000, which if I read correctly means that my TC is not locking up. So, does anybody have any ideas on what could be the issue? Could my TCC solenoid have failed? Is there a connector that could have come off that solenoid? Any and all help is greatly appreciated. It's just so strange to me that this isn't a problem until the truck warms up. Also, if it makes any difference, the truck only has 49,000 miles on it.

[92 5 oh]

well i am no trans expert by any means, but i'll chime in with what little i know...
when my 87 ranger started having trouble with TCC locking up, i was told an easy way to tell if it's working is to allow the trans to get to normal operating temp. then drive at highway speeds. while keeping the throttle at a steady spot, lightly tap the brakes. application of the brakes should take it out of lock up, so your rpm's should go up ~200 or so. I noticed this did work well in my 87 and also in my 98 that i currently have.
Or if you have access to a scanner that does real time data streams you can see if the lock up solonoid is functioning.
additionally, there's a few TSB's for the 5R55E. Some of these include an update seperator plate for the valve body that has a bonded gasket. apparently the original seperator place has seperate gasket which would blow out. i do not know exactly what years are affected by this.
Apparently there's also some issues with lower EPC solonoid pressure at highway cruise speed, again i don't know what years are affected. your local dealer should be able to tell you.
i believe this is a direct link to "5R55E valve body rebuild diary"
http://www.explorerforum.com/forums/...d.php?t=140987
my firewall at work won't let me view the site, but i think this right - if not go to google and search for "5R55E valve body rebuild diary". someone made an amazingly detailed rebuild thread compairing (i think - it's been a while since i read it all) superior, transgo and ford revised parts. maybe your situation is applicable to this thread.
hope that helps some...
Steven

[Fordtruckman80]

Thanks for the reply. I took a trip in the truck, and I realized that the torque converter is definitely locking up, as I can feel lockup when I cruise at a constant speed, and rpms drop a few hundred whenever the TC locks up. So whatever problem i'm having is somewhere else.