'97 Pontiac Sunfire issues -_-

[Debt]

Hi I have a 1997 Pontiac Sinfire, and my dad says I need a new transmission. As they are quite costly, I was wondering if the loud clicking noise it makes while moving in reverse could be anything else?? It kind of jolts as it clicks as well. We had just put a new rack and pinion in the day before, and I think it might have something to do with that. But my dad says we did everything correctly. What all could it be?

 

[melsg5]

Did it make the noise before you changed the steering rack? Did you put the front of the car on jack stands and confirm the noise is coming from the transmission?