My husband and I had just replaced the starter and was backing it off the ramps when it started making a crunching sound and locked up. We only got maybe 50 feet from the ramps. I can feel it going into gear but it won't go anywhere. It's like i have it in neutral revving the engine. Every once and awhile it'll kick into gear and go a foot or 2 and start crunching and stop. I don't know what it is. The transmission was working just fine even with my old starter that would allow it to start every now and then. The only thing that we removed in the process was the skid plate, starter cover, and starter. What could we have done wrong to make my car act like this?