Subaru Repair: 1997 Subaru Legacy shutter when start and stop, old chevy pickups, subaru legacy


Question
Brief history: A few months ago my girlfriend ran over a curb.  Her front end was vibrating badly, so I put new tires on that helped a little then I had new wheel bearing put on the front, that stopped the vibrations.  Now, when she first takes off the rear end shutters, kind of makes a thud-thud-thud sound the runs smooth once she gets going.  I check the u-joint in front of the diff. it was tight, but I could rotate the driveshaft clock-wise and counter cw quite a bit.
I haven't got the slightest clue. I've worked on rears end in old chevy pickups that about it never tackled a Subaru.
Also, when I push in on the brake peddle the car shutters a little and the brake peddle pushes back and pulls in repeatedly just a little bit.  Warped rotors maybe. It feels like thats in the front end. Any advice would be greatly appreciated.  Thanks

Answer
I'll answer the easy queation first. The pulsation in the brake pedal indicated wared rotors in the rear. Steering wheel shake when braking would be the front rotors. As far as the thud noise when taking off, that I would have to listen to or look at. Sorry, Could be rust on rotors, wheel bearing, axle, a number of different things.