So, I have this secondary fan installed on the left side of my main radiator fan. Staring today, I am getting a loud rattle but only at certain RPMs. Anyone else have something like this?

CF Veteran
That part number is the stock electric (aux) fan. Is that where your rattle is coming from?
You can no longer buy that part number, you have to get the fan/shroud as an assembly # 52005748
You can no longer buy that part number, you have to get the fan/shroud as an assembly # 52005748