If I replace the cam phasers with new ones, are the new ones redesigned, or will they eventually be like the old ones and have to be replaced again. I haven't got the noise from them yet with 70K, but was just curious if/when it happens if they fixed the problem.

 

I replaced both of mine at about 80k, I now have 101k. My passenger side one was fine but the drivers side had been noisy since I bought it at 34k. For good measure I replaced both and its quiet as new. I got lucky and found the newer part number on ebay for $80