Does changing the rear axle = new wheel bearing?
 

If I replace the rear axle, do I need to replace the wheel bearing also?

As long as it( the axle) is not seized into the hub splines then you should be OK. I have been able to pull mine numerous times before.

why do you need a new axle?

experiences vary greatly as to how easily (or not) the axle separates from the upright. my recent experience was that the axle was close to impossible to remove without overly beating on it or putting too much heat into the aluminum carrier. so i removed the axle and hub/upright as an assembly and took it to my drivetrain guy. he found he had to soak it in some special penetrant overnight and then had no major problem removing it. you shouldn't damage your bearing removing an axle. if you have to remove your hub from the upright you will have to replace the bearing.

BTW, others have said they just tapped on the end of the axle ( with the nut on it) and it separated.

good luck,

howard coleman