The noise should not be normal. You may have a bearing going out causing excessive movement and the poping out problem.
There is a stronger spring that you can install, but don't know it it by it's self will fix the problem.
You should pull it apart and check the bearings before you do damage that can't be repaired wirhout buying new gears.
You are 100% sure the floor or nothing else is touching the shifter while you are driving?
