Expert: Roland Finston - 8/22/2011

Question
Hi Roland.
My wife drives an 02 Town & Country with 130K wich we bought used(117K), i'm not sure if the tranny had ever been serviced(no problems at all), but I decided to drop the pan, replace the filter, gasket and 4.5 qts of atf+4 fluid(that's how much came out) so after finishing I took it out for a test drive and it shifted smooth, no problems, but when I pressed the brake, as soon as the speed needle passed the 30mph mark(going down) I feel a little bump and than everything feels normal again. and also when going at highway speed the RPM's seem to stay a little bit over 2K like if the overdrive was not kiking in. (I only drove it a couple of miles) I disconected the battery before droping the pan. Do I have to do a realearn procedure or did I mess something up???

Answer
Hi Javier,
I don't think you did it wrong. I would check the level of the transfluid on the dipstick. Then if you aren't noticing the the rpm to drop about 5% when you exceed about 40 mph that means that the torque converter 'lockup' function is not working. This feature reduces slippage in the torque converter. The lock-up should disengage, if it does engage when going up speed, when you slow down to around 30, as you mentioned. If you believe the there is a problem you could get a code readout, for free at most nationwide parts stores such as Autozone, to see if there is anything stored in the memory of the transmission controller which would tell a fault code that could be followed up upon. Let me know any such 4-digit fault codes.
You can try the quick-learn procedure:
Transaxle must be warmed up.
Maintain constant throttle opening during shifts
Do not move accelerator pedal during upshifts
Accelerate vehicle with throttle opening angle in the range of 10 to 50 degress
Make 15-20: 1-2,2-3, 3-4 upshifts. Accelerate from stop to about 45 mph each time at a moderate throttle opening angle.

With vehicle speed below 25 mph make 5 to 8 wide open throttle kick downs from to either third or second gear from 4th gear (4-3 or 4-2 for example).
Do the same with vehicle speeds above 25 mph do the same kick downs with part to wide open throttle position. Allow for 5 seconds or more in 4th, preferably at road load throttle prior to performing kick downs.

This should optimize shift quality.

Otherwise, a DRB III scan tool is needed to do this automatically followign a specific protocal that is programmed into its cartridge.


Roland
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