Chevy Impala transmission won't shift
I have an 06 impala with the 3.5 and about 145000 miles, I've had issues with it not shifting out if first, but was always able to shift it manually, until yesterday, now it won't shift out of first at all! There isn't any slip, when it did shift it was always firm, and solid, the way it should be, sometimes at low speeds if I speed up to pass someone it down shift, and wouldn't shift back up. Is this common? What do I do to fix it?