Auto transmission issue
 

I am having an issue with the auto transmission on my Grand Voyager. It has been serviced with the correct Mopar ATF+4 oil and new filter.
At low rpm when the engine and transmission are at working temperature there is a very harsh shift from 1st to 2nd and a clunk as it engages. All other gear engagements are fine up/down shift when hot/cold. All shifts are smooth when cold.
From the previous owner it has 18" wheels installed which I will be changing ASAP as the speedo is slightly out. Could this effect the harshness of the transmission shifts?
I am suspecting that it could be the solenoid pack as if I rev higher it changes smoother suggesting a possible leak inside the pack or sticking valve?
I don't have any means of reading codes other than the dealership as the scan tool I have won't read the transmission brain.
Regards
Dan

I would just check one thing first before delving into the autobox body, which requires experience and money; make sure the brake-light switch is operating as it should, and you aren't resting your foot on the brake pedal AT ALL when driving. I found the same symptoms as you're experiencing because of this.

Leedsman.

As a follow up I was able to get a launch diagnostics tablet plugged in to my car. On looking at the TCM it showed a temperature sensor and loss of prime fault. I believe due to probably not being serviced for a while. Got these deleted and drove for a bit and rechecked. They didn't reappear. Then used the quick learn function to reset the CVI (clutch volume index) readings for the TCM and I can now say it is driving like new again with extremely smooth gear changes rather than trying to give me whiplash.

That's a relief...
It seems that disconnecting the battery can cause these problems in earlier autoboxes. There is a procedure to go through if this be the case, involving driving it in a particular fashion. They must be using non-volatile memory in later boxes as this effect does not happen, and the learning data are not lost.
Time to break out the Moet, autobox faults always scare me because of the possible cost.

Leedsman.

- the driving style 'learn' routine is a function of Chrysler's default programming
- different strokes for different style, ie smooth & gentle versus clog happy
- the quick learn is and has always been there as far as I'm aware