I just bought the truck today. The 4 wheel drive works well however, it seems like it takes more force than it should to put it in 4 wheel. THe owner I purchsed the truck from said it only put the truck in 4 wheel drive twice since it was new. I did carfax the vehicle prior to purchsing and he is in fact the original owner. The truck is in good running order and very clean inside and out, only has 66k. Should I be worried about the 4 wheel drive system?