Grand Cherokee had inconsistent transmission behavior then stalled

good afternoon group. looking for some insight on what i encountered. i have a 2010 grand cherokee ltd, with 5.7. after a 2hour drive, the local roads were hilly, coming down a hill (30-40mph) i manually downshifted to 4th, 3rd, then 2nd to slow down, not ride the brakes as much, transmission wouldn't manually downshift, (it did show the downshifting on the dash though), however, it stayed in drive mode. it did downshift on its own as i came to a stop. jeep shifted perfectly for another 20min of driving, not manually downshifting though. Next day, going from park to reverse, it was chattering in reverse, jeep didn't move. went into drive fine, chattered again when i put it back into reverse, same- didn't move. took it for a ride, shifted perfect. this whole time, no check engine light. went on the highway, shifted fine and downshifted as well. still on the hwy, when i took my foot of the gas, i noticed the rpms go to 1000, gave it gas and it was like it was in neutral, transmission caught up to the speed i was doing (60) and banged. got off an exit, put it in park, then reverse, still chattered, back into drive and nothing. jeep was dead. shut it off, went underneath, checked wired and banged with a flashlight (what looked like a solenoid) with wires going into it. Started the jeep, working perfectly like nothing never happened. Reverse is perfect, drive, and downshifting. what could've caused these symptoms? any feedback would be much appreciated

 

I would start by checking for codes. A good scanner is needed as trans codes do not not always show up with el cheapos.

FYI: you can have codes and the CEL remains off.

do you know which trans ? IIRC either a 545RFE or a NAG1. The NAG1 is my guess but want to double check.

 

thank you, not sure of the transmission, how can i find out what's in there?

 

concentrate on getting a scanner on the system.

 

yep, will have that done this week. thank you