I have a front case fan that mounts in a plastic unit/clip doohicky. The problem is, this thing makes a loud vibrational noise and when I put the fan in the back, it does not make the noise. What can I do? The clip is fairly tight, and there's no room for foam in there.

I'll post pics in a minute...
EDIT:
Piccies! All very small, very low quality (my webcam sux) <25KB

Fan Assembly Inside
Fan assembly outside
Where the assembly attaches to on the case (I have to cut that grill one of these days...prob. next week)

Unrelated Pic:

My super-quiet, ultra inexpensive HDD 'mod'. LOL
As you can see, the front case fan is mostly for cooling the hard drive. Turning it off has little effect on the case temps (maybe 2-3 C under load). If the HDD is under load, and I turn it off, the HDD temp goes way too high for comfort. Oh, and I have no 3.5'' bays as you can see. No floppy, one HDD, I really didn't see the need for another one. Good for airflow in the front of the case.

All I can see in your pictures are wires, LOL. I will try to work out what is what hee hee.

Between the lighting and the shot quality, it's just plain bad. I'm fixing them now...

Fixed! The links are above. Same resolution, much higher quality (and the lighting is a whole lot better too.

I fixed the fans temporarily by cutting up an old audio cable, and tying the fan to the front of the case. It reduced the vibrational noise quite a bit.


The fan itself though is noisy as hell.
Note to everyone: Stay away from thermally controlled fans. They are loud, and difficult to control.Here's a pic
It's not touching the case which helps a lot.

I love that HD casing!
Do those fan mounts dampen the noise? Or do they just look fancy, lol.

The 'mounts' do reduce the noise from the vibrations. The whine that the fan makes is still there though.

Good point. Thermally controlled fans, while a good idea, are not always the best option. Most thermally controlled fans are noisier at their lowest speed setting than a comparable undervolted (or full-volted for that matter) Panaflo-equivalent fans.

Now if you really want to get quiet, try hooking up a Panaflo to a thermal controller (like ASUS's Q-fan on the motherboard). That way you get just enough cooling with minimal noise from an already-quiet fan. You just can't lose!

You can install Speedfan ( http://www.almico.com/speedfan.php ) and get intelligent thermal control for most motherboards.
And you cant beat the price (freeware)

what type of case are you using?