Hello, transmission is growling/sometimes feels

hello, transmission is growling/sometimes feels like it is jumping between 3rd and 4th and now when putting into d or r it sounds like pieces are stirring around in side. But as of now it still will drive thru all the gears and even when you put your foot into it.can something else cause trans to make these noises? history tells me no but /HELP!!! also when cold brake light comes on and then goes out after driving