Just out of curiosity maybe someone can help me solve this. On my truck when im going up hill sometimes it seems like my truck just shakes like maybe it needs to downshift. It has 160k miles but i swear i thought an allison should go longer than that on a stock truck. I'm thinking maybe i need to grease to U joints and probably need change the tranny fluid. Its still red and has no burnt smell but the filter on the trans looks kinda old. But i have read that if you have never greased your U joints it could cause kind of a shaking type feeling. And this felling really only happens when im going up a sorta hill most of the time and going around 45-65mps. Any thoughts?