'01 SSEi Transmission Issues -UPDATE

[Oldman]

Transmission stopped pulling on Friday. Would bog down like differential locking up when taking off. Then would get up to about 30 MPH and the engine would just rev up.
I limped home and changed the transmission fluid. That's pretty much all I know how to do on an automatic transmission.
It actually is working now - sort of.
I've learned by playing around with it that once it's warmed up, if I come to a complete stop and put the shifter in "3", it takes off and changes through the gears like it's supposed to. But if I start off in "D", it chugs, bucks and does all sorts of strange stuff. Also, if it's in "3" and I get up to speed and then put it into "D", it starts acting up. It jerks like a very severe engine misfire, but it's not the engine.
I'm wondering if there's some trash in the valve body, or what might be the problem. When it went out, changing the fluid helped get it going. Is there anything you guys can suggest. We're down to one car right now, and it's this one. Yeah, my '01 Bonneville with 245,000 miles on it is the "GOOD" car!
Thanks for anything you can suggest. I've got a 12 hour drive for the July 4th weekend and it looks like I'll be renting something to drive.
Thanks,
On a regular basis, when I come to a full stop it shudders and shuts off. I have to rev it in neutral and put it in gear. When it doesn't do this, when I take off from a traffic light, it shudders badly until I get up to about 20 MPH.
Is there a SES code that lets you know that you have stored transmission codes? Can auto parts stores scan for transmission codes, or only a transmission shop? From what I'm reading online, it sounds like a bad torque converter.
I sure need some help here guys.
Thanks,
We're down to one car now and car pooling doesn't work well for grown-ups!

[harofreak00]

Sounds like a classic engine misfire, exactly like you said its not. What makes you so sure its not?

[Oldman]

No SES codes, and a major transmission melt down just prior to this. May be dealing with two issues at once here. Today, it pulled up to a red light and it shut off. I had to crank it up, rev it up and slam it into gear to get it to go. Its like the torque converter was locked up or something. I just don't know what I'm dealing with here. When it acts up, if I shut it off and crank it back up again, the transmission seems to work better.
Thanks for any suggestions you might have.

[robauto]

it sounds like the tranny is bad, probably the torque converter, does the tranny have 250k miles on it? if it does, that is pretty good and you probably reached its life. check for transmission codes, you probably have a few of them- delayed shift, etc. Not much you can do or should do, bring it to a trans shop for a free evaluation.

[96 SSEi]

hi, I would be looking for someone with a high end tech 2 scanner that can pull and command trans. components so you can narrow the issue- did you get a warranty from trans repair? - take it back and hear what they have to say

[spidey3479]

Worst case scenario is a rebuild. Get it done by a national chain or a reputable shop. Put the best tranny fluid, Dex 6 or royal purple max atf. And have them put a cooler on it. It would be cool if you can put a shift kit in it too. Been through 2 of these, one on the SSEI and one on my truck. Be the best 1200-1400 you can spend. Otherwise it will just get worse.