Chrysler with 604 Automatic torque converter chatter?

I have a 2004 Chrysler Sebring LXi Convertible with the 604 transmission. During torque converter lock-up, the transition is way too slow... by design and it chatters violently. There has to be a fix for this, and the dealers haven't got a clue. It's such a simple software re-write, but I can't get in there. Is there anybody out there who can "flash" the TCM, or sell me one, or find the right fix? I know this is a MAJOR problem with these transmissions. Why doesn't someone FIX it? Can anybody help? Chrysler ignores the problem, but I know there is a bulletin on it, and it requires the replacement of the torque converter AND a rewrite of the software... but they look at me like I have two heads... What is going on here...?

Try looking in the archives related to transmission issues with the 604 unit and ask your question on this specialty forum for Chrysler products: www.allpar.com. There are some very knowledgeable people there and I have found good solutions that "professional" mechanics and the dealer didn't know about.

Fluid: Are you using the EXACT Mopar spec ATF+3 or ATF+4 auto trans fluid? That will make a difference.

"Makes a noise" Could be as simple as a solenoid that is bad, not opening electromagnetically hence the chatter. Does it shift/function in other or any "gears" or does it do it in just one? How many miles are on the unit? 150k range is a good life, if more then it could be torque converter. If less look for other issues and I emphasize the correct ATF fluid mentioned above is crucial, not just an option.

dodge/Chrysler have problems with the torque converters when they get into the high mileage range probably going to have to have it replaced. re-flash won't work if the clutch inside of the converter already gone. find more help at ATRA,COM

We had this problem with the rear wheel drive cars and the ATF2 came out to stop the problem. You could try changing the fluid with ATF4 which has all the latest improvements. I don't think it would be in the solenoid or any electrical.

You have the Chrysler Ultradrive. These are notorious for many problems. On line there is a wealth of information on these trannys.

Hi Richard

when torque converters make noise in what is essentially a fluid drive system. the chances it is something mechanical that is failing due to bearing wear within it.

Hi you are right it does need a new torque converter this simple logic is a forgien language these days to these kids in most fitting shops. they are not mechanics just fitters.