First question...did you disconnect the axle from the transmission before you started "hammering" to knock it loose from the hub (rotor)?
If you left this connected while hammering, it could be very bad news as the blunt force would be transferred directly into the transmission...which in turn could destroy the differential.
Secondly, you mentioned you had to hammer the new axle in? Are you sure you got the right axle? It should have just slipped right into the hub if all of the splines were lined up. You just should have needed to tighten the hub nut.
Best case you just wrecked the front wheel bearings while "hammering" the rotor side of the axle in. Worse case the hammering damaged something internally on the tranny.
There should have been no hammering necessary, at most a couple taps with a rubber mallet.
Found this elsewhere on the web:
Replacing a CV is not overly hard to do. I suggest getting the latest Haynes service manual for assistance.
You need the following tools and parts
* liquid wrench penetrating oil
* 1/2 drive torque wrench
* 1/2 drive breaker bar
* 1/2 drive 31/32mm socket
* metric wrenches or sockets for the control arm/end-link bolts
* small punch to knock the DOJ joint transmission outdrive pin out
* hammer (for the above punch)
* rubber mallet to tap to push axle out of hub (usually not required)
* replacement CV axle
* replacement axle nut (DO NOT REUSE the old one)
* replacement cotter pin for the ball joint nut
Step 1: spray the axle nut, tie rod nut and DOJ pin with penetrating oil once a day for a few days before the work is to be done.
Step 2: using the 31/32 mm socket and breaker pull remove the axle nut (this is sometimes difficult) (you should use a hardened impact wrench socket, I have seen regular ones shatter)
Step 3: remove bolt from lower control arm to the sway bar end-link.
Step 4: remove bolt front lower control arm at the front mounting point.
Step 5: remove the pin from the inner CV joint.
Step 6: with the end-link & lower control arm frount mount loose you should be able to pull the inner DOJ joint off the transmission outdrive.
Step 7: Pull the CV axle out of the hub.
Step 8: If necessary, use the rubber mallet to tap the CV axle out of the hub. It's a good idea to reinstall the axle nut loosely to protect the axle threads before tapping the axle gently loose.
Reverse for installation of new axle.