I have a 95 Cutlass supreme sl 3.1. It starts fine but there's a squealing sound, it will shift but when you accelerate it make s a crunching sound. Once the squeal stops it wont shift at all.

Car suddenly bucked coming from a stop sign.  went to a gas station and left it
running, when I came back out it wouldn't shift into any gear.  I turned it off and back
on and then it shifted fine.  I got back home and changed the fluid and filter.  I drove it
for about 20 miles on the highway and it seemed fine.  Once I got back to town I
noticed a crunching sound at low speed that sounded like it was coming from an axle.  
Now the car started to squeal when started but will shift fine.  Once the squeal goes
away the car won't shift at all until I turn it off and back on.  Still makes the crunching
sound at low speeds.