[2004PTCruiser]

Hello all
My 2004 non turbo pt cruiser auto with 54500 miles just dumped the transmission this morning After getting it to the dealer he says something internal is broken and it will have to come out and be taken apart to see the problem and if possible they will rebuild it and if not they will put in a reman...
so I was wondering if any of you guys have see or heard of this and what it could be

here is what happend on my way to work I pulled out to pass and went about 1/2 pedel and all it did was rev up to about 7000 rpm and thats all it would do so i pulled into a parking lot and it would not go in reverse but it would pull in forward but not far maybe 50yards or so and then nothing again

so what do you think it could be anyone
also could I have broken anything in the motor by reving it up to 7000 rpms

also the tranmission fluid was changed by the dealer just a week or so ago and it seemed to have a shudder between second and third gear on takeoff