Vibration from Fan

When my fan turns on it sounds like a jet, it vibrates to the point that it has cracked a weld on the A/C and leaked out the freon, Can anyone tell me the solution to my problem.

Hi
Are you talking about the radiator cooling fans under the hood? I have no specifice experience with the problem you describe, but I would guess and out-of-balance problem with the fan itself, or perhaps an internal failure in the motor causing a similar balance issue. I might visually inspect the fans for anything that would obviously cause the problem: a chunk missing from a portion of the fan for instance, but in the long run I would probably look at a remove:replace of the suspected fan. By the way, if the rad fans are what we are discussing, do you know which one is at fault?

I had this recently on a Thunderbird. The fan blade cracked and would expand to a larger diameter when running. It actually shook the lower rad hose from the radiator. Ford only sells the whole fan/motor/housing assembly and it's close to $300. I'd recommend a yard. I found one fo the T-Bird for $50 and is like-new.
Marc/Atlanta