Drive axles loose where they go into the transmission.

they are making a popping noise.

If they are popping, especially when turning, then the CV joints are likely bad. If this is the case, you may also see that the CV boots are torn, which is often the reason the joints fail, because the grease leaks out of the joint. If indeed the joints are the problem, it will be most economical to replace the axle(s) that are noisy.