I have a 2002 tundra with 37k miles on it. Got the truck when it was new, I dont drive to far to get to work, so it saves on the miles. Does the belt need to be changed at 90k miles/5 years...witch would be now for me...or just at 90k miles, years do not matter. I live in denver, very dry climate, does this affect it at all? I know my sepantine belt needs to be changed very soon, its dry and cracked, will be the first one ive gotten, not sure about the timing belt though.