2011 Toyota RAV4 shifts really hard

Have a 2011 Rev 4WD and was wondering if maybe u could tell me what years are affected by this poor programing or ECM problem? My 2011 4WD Limited 2.5 to be exact. I hate to say it. Mt tranny has been acting up in the past two weeks or so. It only happens on hills at slow speeds so far. I live at the very top of a mountain, 12,082 feet above sea level, and here lately it shifts really hard, only after seeming to be slipping or bumped into neutral. Although I`m no Master Mechanic by fair, I do however, understand the basics of an automobile, but let me tell u something right now! This Rev is something else when it comes to diagnose of problems! Like why mine makes an offal roar, roar, roar, roar, coming from the front end that gets louder and faster as speed increases. Sounds really terrible I`d say and I want it fixed. Just tell me the source of the noise and stand back cause I`m bout to make something happin!