When I am slowing down to a stop, just at a few miles-per-hour before stopping, transmission will shift down to what appear to be first gear prematurely, giving me a harsh jerk.... kinda as popping the clutch in first gear just before stopping on a stick shift car. I have 80,000 miles in this van and it started to do this recently. Besides this issue, van is shifting nicely and overall running great. Anybody had seen this? Is the premature downshift induced by a computer or by the actual tranny?

 

If you have recently replaced the tranny fluid/filter with ATF+4 it may be that the tranny computer is in learning mode. If that is the case it will go away with time. If not, then you should have it scanned for the codes. It takes a complex scanner to read the tranny data. The $tealer has one and so do some transmission shops. I would wait a few hundred miles and see if it's learning, as the harsh downshift will go away. If it doesn't self correct then you probably have a problem and better save for a quality rebuild unit.

 

I have not change the transmissiom fluid (ever) in this van. Will it be an intelligent asumption that this may be the source of my problem? Is the Slick 50 Transmission Additive any good to be added when I do it?

 

The problem you described is called "bump shift" and is pretty common with the 604/41te.

A fluid change would be a good place to start. Drive it around a few days after the change and see if it improves. Like webbee said the trans has to "relearn" after a fluid change.

Depending on the year, the TCM may need "flashed" or the solenoid pack may be faulty. You'll need to see the dealer to check the TCM, while your there you can get the codes checked.

Lotsa good reading on the subject over here: http://www.allpar.com/fix/trans.html

 

The trans controller will take for ever to do a relearn on its own. You will get to the point of dumping it in the river before the bump shift will go away. Basically it is a 4th to 3rd gear downshift bump, and the quickest way to get rid of it is to have your dealer do a quicklearn on the trans control module. Takes all of 45 seconds to reset the transmission controller and give it a new set of baseline values. Do not add any aftermarket additives to the transmission fluid. The ATF +3 that you have in your (since you stated that it has never been serviced) has a lot of special additives in it to prevent shift shudders, adding aftermarket stuff to it reduces the friction modifiers in the oil and will cause shifting concerns. By the way, you should have the transmission serviced, the interval is 30K miles.

 

I did not see a recommendation to change the fluid in the service schedule whatsoever. that make me really mad and dissapoited at Chrysler. I will change the fluid and install a Mopar filter within the next week or so and observe the results, which will be posted here. Oldbuddyjack stated "Depending on the year, the TCM may need "flashed". Does anyone knows if this apply to my 2003 model?

 

I have never heard of a quick learn needing to be done for a tranny service, while I understand the reasoning you say it might. The auto learn is not that slow if you do any kind of moderate driving where you hit highway speeds and stop and go speed ranges. While really "wiped out flluid and totally burnt" may change pump pressure values and in addition change shift points subtley, unless the TCMis clearedor the tranny has a hard part,, solenoid pack, torque converter or speed senson changed the existing values should not be that far off and the TCM should adapt.

 

If you look under schedule B you will find the transmission service in there. Schedule A I believe has the transmission serivce at like 100K miles. Nobody is schedule A, that is under ideal driving conditions which don't exist except in a labratory.

I never said to do a quicklearn with a trans service, I said to do the quicklearn to reset the trans controller, and do a trans service because it hasn't been done. The service alone won't change anything other than the fluid and filter.

 

Had the same problem. They had to replace the electronic shifting module. Fixed the problem and was covered under warrenty.

 

I changed the oil and filter. When you buy the filter, it will not come with a gasket since they used RTV at the factory. You'll have to buy a tube of RTV; buy the silver one (for imports/aluminum surfaces). Disconnect the battery, raise and secure the vehicle, loosen the oil pan and drain, remove the pan and clean it up. Apply an aprox 1/8" line of RTV Siliconeto a clean oil pan, looping around the bolt holes, let it sit for 20 minutes then assemble and let it sit an hour or2after installation (trust me), then refill with ATF+3 or ATF+4 tranny oil (not Dexron). I was frustrated 'cuse the bump continued after that, but after a couple of weeks...GONE! (I drive 300 miles a week). The auto parts store will tell you how much oil you'll need, I think you'll need about 6 or 7... I forgot. When buying the filter, go to your dodge dealer, but buy the RTV in Advance Auto, Pep Boysor Autozone.Thats my story. If you dont have skills to do this, let me know, I'll tell you how to do it...its easy. All you need is a rachet, socket with a long or mediumt extension, paper towels and the partsto do the job. I used a wire wheel on my cordless drill to clean the pan matting surface, it works awesome and faster than a scraper.