so in one one of the books(to lazy to check) jacob detto something about not getting older untill the give up the wearwofl thing so can jacob live for ever?( idk maybe i read the passage wrong)

Well i am not sure about forever, but he can definatley live for a long time. Like in the Quileute legend about the third wife, they mention that someone [i dont remember the name now] lived the lifetime of three life's... so yeah i am not sure about forever though. Its possible though, cause the process of getting older stops when he is in his lupo form. And he is a shape shifter.

If I remember well, the story of the third wife is in the Eclipse, I too don't think they can live forever, they just age much slower, and they can be in that certain age as long as their tribe needs their protection...

A werewolf can live forever as long as he o she keeps shifting into the lupo form. Normally, the lupo will choose to begin ageing again once his o her imprint is at the same age, unless he o she has imprinted on an immortal.