VISTABLUECS

I have a 2010 Roush Mustang with the blower on it. It has about 13000 miles on it and I baby the car. Today when was pulling into the driveway I noticed a bad vibration coming from under the car when in first gear and letting out the clutch. I have never had this issue before. It does not do this in any other gear but 1st. It does it worse under a load (up an incline or with no RPM's) any ideas?

Blacksmoke

Sounds like clutch chatter.

Try to find out what kind of clutch you have. It could be a non organic clutch which can chatter.
Try feathering it less and letting off the clutch faster.