Its a C4. I know, its not a mopar but yall are really helpful and I figure at least one of yall works at a shop that works on all transmissions. Besides, I would think that most auto transmissions are built somewhat alike. Its on my mom's 76 Elite. The car has only 80,000 original miles on it.
I changed the filter and fluid and put Valvoline fluid and one quart of Lucas Stop slip in. The filter is a Pioneer from O'reillys. We're not sure how old the filter or fluid was but considering it only has 80,000 miles I doubt that it has been changed until now. The filter was fairly clogged, or at least it appeared to be. There was not hardly any metal in the pan and no gunk or sludge. The little metal that I did notice was actually more of a metallic powder in the fluid.
When the car gets up to shifting RPM it shudders and won't rev any higher, but also won't shift. The first shift is at around 20 mph and unless you let off the gas it will not shift. It just started doing this recently. If you let off the gas it will shift, but it does it slow. The first time it happened it did it at 55 trying to go into overdrive. Now after changing the fluid/filter it does it at every gear.
I really don't know much about transmissions. Well, I don't know a whole lot about working on cars either but I"m learning. Thanks for the help yall. I know it's not a mopar but my mom loves this car. Her mom bought it brand new and when she passed away she gave it to my mom.