Transmission "lunge" when coming to a stop...

[bojified]

1992 940 GL B230 NA with AW 03-70L 3 speed auto with OD. 142000 miles.
This car is fairly new to me but as you can see in my sig I am not new to the AW trannys. Right after I purchased I did all fluids including a 'flush' with the iPd hose of the transmission. I have had the car since October and it is my DD. The tranny shifts great while in motion. All the shift points seem appropriate. When coming to a stop 9 times out of 10 just as I am coming to a complete stop (literally in the final few feet) the car lunges as if hit from the rear. If I get in a hurry and don't come to complete stop- as I push the gas to go there is even a bigger jolt and the engine RPMs get drug down then I go and everything is fine. It did this when I test drove it. Also even though there was a recipt from a reputable local indy shop that the fluid had been flushed two years ago it was quite brown. The flush I did seem to not change the shifting issue.

It seems to be as the tranny is shifting into first- or out of OD as with the NA engine and the 4:10 rear end the OD comes in in town driving and the torque converter "Lock up" is tied into the same system because if you relase the OD by the switch (which shuts off the solonoid valve as I had another NA redblock with same tranny and did the cheap drill out of the solonoid passage).

This is not an electronic tranny and there is no computer involved unlike my 2003 CHrysler TC which had to have MOPAR fluid or it acted in a similar way.

My questions are:
Has anyone else encountered this and if so is it the OD or the torque converter....or a sticky ball valve?

I am tempted to re-flush with syn fluid however I am not sure syn has any more detergent action than a name brand DEX III.

Thanks
Scot

[lummert]

Maybe the lock-up torque converter.

[bojified]

Thanks for the reply.

Yes the more I process the problem the more I also think it is the converter unlocking.

Matbe look for a different converter?

Thanks
Scot