I just replaced all my belts because they were old and starting to squeal despite being tensioned. I got it all back together and took it out and now it's developed a definite shaking/shuddering whenever the rpm's start to come up around 4k. I double and triple checked to make sure I had all the nuts holding the fan on tight but it still looks like the fan is wobbling a little bit at idle, and worse when i rev it. is there a specific orientation the fan must have when it's put back on?
Patrick

 

Wouldn't think so, but you can always remove it and turn it 90* to see if that helps. Did you get any debris under the mounting flange for the fan, cocking it off a little?

 

I know its obvious but FIX this ASAP and recommend dont drive till you do. I completel;y destroyed a Celica a bunch of years ago under similar circumstances. Small wobble at 3500+, thought it would be ok til I figured it out. Long story short, the wobble "wobbled" the fan off and it tore into my engine rad belts radiator water pump hoses etc etc ended up sellin car for a couple of hundred bucks on the side of the highway just to get home.