flush was performed. Transtune from seafoam was added.
ETM is xemodex.MAF was cleaned.

when i coast to stop rpms would drop for a moment to 650-700-750 and then would go back up to 850-900. At the same time I would experience a slight shudder.

Also when coming away from the stop or just pushing the accel pedal when speed is not to high, I hear a rumbling noise from the transmission as it is having a hard time. Revs do not go up as when the trans is slipping, but that rumbling is very audible.

I think that my torque converter is going. Would these symptoms be indicative of the problems with torque converter?

Is the shudder at every stop or just after you have gone fast enough to engage the torque converter lockup? Check your records and with the dealer and make sure you have the new and improved software for the TCU.

Check the level of the ATF with the engine running. Mine made a real garbage can noise when the fluid was low.

Is yours a 5 speed or 4 speed, what kind of ATF did you use for your flush?

Klaus
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Always willing to listen, just not able to take direction.

it's a 4 speed, so it takes regular DEX III ATF.
i checked level after stopping the car on level surface, going throug all gears and keeping it there for 5+ seconds, then in Park and wait another 3 minutes and while engine is running check the hot level. It all checked out: level is good, color is good.
shudder happens when I brake either normally or hard. If I really baby it the rpm drop is not as noticeable and shudder is not as pronounced.
I've been to a dealer and asked them about the tcm upgrade as I read a few TSBs from ALLDATA, but they were reluctant to do it and also told me that they do not have any upgrades for 4 speeds, but for 5 speed auto transmissions only.
i'd need to talk to them again.

I hope you flushed it yourself and not via machine.

Try getting up to speed, shifting to N as you are slowing to a stop. Watch the rpm, it should not go below 950. If the rpm goes below and then comes back up to 950, clean the idle air control and/or the throttle body.

Klaus
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Always willing to listen, just not able to take direction.

i did drain and refill by myself. no machine involved.
my guess about transmission/torque converter is actually based on the fact that I've done the coast to stop in neutral and the rpms are rock solid.
it happens only when there's load from the transmission and, more importantly, after the transmission is warmed up (this does not happen on the cold one).
no AIC on 99+, but I did install xemodex etm not long ago, and it was very clean.

Actually, looking back at the situation, I had a white sticker Volvo ETM with campaign 155 software update and the same thing was happening, which led me to believe that the problem is the ETM, hence the XEMODEX one that I installed.

How does the fluid look? Appropriate level and color?
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If you're not driving it "like its stolen," are you really driving?

it's at athe right level and the color is bright red, since the flush was done a few thousand miles ago.