Ok

Ok. This issue has been posted a few times with what seems to be no clear idea on why it has happened.

My situation is this.
Bought a 2004 grand Rocky mtn. With 4.7HO and 545rfe quadtrackII.
Got all fluids changed that day incl trans flush through the dip with proper amount and type fluids refilled incl small amount of additive and no cleaning agents. Vehicle is in very good condition, no rebuilds or recorded powertrain issues. It has always been serviced at dealerships on schedule and has 135,000KM.
Shortly after driving I stopped and noticed smell from rear. Turns out my ebrake was stuck ever so slightly and caused the area to heat up and wear the pad.
I let it cool down, started her up and made sure the ebrake was not stuck.
ABS and Ebrake lights came on, and I had no power to my signals. I was in traffic so I immediately pulled over, came to a FULL STOP and tried to put it into park.

Now after the short story here's the problem.
With my foot on the brake and at a full stop with the jeep idling I put it into park as usual. There was a rapid buzzing/ light grinding noise from what seemed to be below me. I quickly shifted to neutral with the same effect. I then quickly shifted back to park and shut off the jeep. I waited a minute and then restarted her. Everything was fine.
Who knows what the hell happened and if I did any damage or if I should get it checked out.

I need to get to the bottom of this quickly so I can have the mechanic who did the safety or the fluid change "experts" held responsible for possible negligence and/ or damage to my new Jeep. I'm going after the safety mech cus the ebrake could not have been checked since it stuck with no red light on and it was only the one hub. Probably destroyed my ebrake and rotor and possibly wheel bearing but im getting off track with the main issue.

So far my research has led me to believe it may have been the parking pawl trying to engage but the locking gear was still spinning. Others have pointed to it being the starter engaged and grinding on the flex plate. Others have said it my have something to do with the torque converter. Some say it has to do with a solenoid not engaging due to the power failure? Ive also read that it could have been the sun gear or planetary gears grinding which I dont think is true cus the vehicle was at a dead stop. Some say it may be the tcase, again I dont think so as I was totally stopped.

As I said there are many exact cases reported here and on other sites and on other vehicles. Who knows what the hell happened?

Thanks, Joel