Toyota Repair: actuator/axle problem, splined shaft, toyota tundra

Question
Hi i own a 2002 toyota tundra auto 4.7l v8 extra cab. my 4wd has never really worked. it would slip in and out and grab. So i suspected the front actuator. after unbolting it i discovered metal flakes insde the opening to the axlehousing. And that the actuatior seemed to not function properly. it would only kind of move when the 4wd button was pressed. i dont suspect the ring and pinion because i drive it everyday in 2wd(i supect the ring and pinion still move in 2wd) please help

Answer
Even in 2wd the front axles and differential still turn, they're just not locked by the actuator, until the actuator engages the locking sleeve there is no 4x4. The metal particles are cause for concern, drain the front differential and check the condition of the fluid comiong out, see if there are a lot of metal pieces or shavings stuck to the magnetic drain plug, if there is only a small amount it would be from normal wear especially if there is no noise when driving, the actuator may be the whole problem, if it's not working and engaging the sleeve and the splined shaft it could be where the metal flakes are coming from.