tranny/rear end?

[Stang67401]

hey guys i had a quick question... and the answer maybe something i might not like lol. i drive a auto and whenever i go from park to drive i hear a little scratchy sound coming from the rear end. the car kind of jolts a little bit and the battery goes down a couple volts but after a second everything goes to normal.

any help would be awesome thanks guys :-(

 

[95-stang]

I would have said the fan belts losing grip under load, once your going its ok again, just check to see if the fan belts slipping or not.
It would explain your voltage drop.