It is highly recommended that you replace the two transaxle seals whenever you do an axle. The old seals get hard, inflexible and brittle and can be damaged on removal of the old axles. The seals are cheap, so replace them while you are in the neighborhood. Be careful, when pulling them out, not to mar the bore in which they are seated.

I find that it more economical and satisfying when I replace everything at the same time. I've divided my front suspension into four systems: 1) brakes, lower suspension (A-arm w/ball joint, inner and outer tie rod ends), upper suspension (strut, spring seat, strut bearing) and driveshaft (including the hubs and seal). If an part in each of these four systems fail, I replace all the parts in that system, on both side of the car, at the same time. I have found that if one part of a system is failing, odds are that the other parts in the system are not far behind.