Mark,
It's certainly possible, but once you've removed the axles, why don't you put 30 more minutes into the job which is required to remove the differential altogether? That way, you'll be able to put it on a bench, clean it, inspect it, and replace the input seal. And if you want to go a step further, you can replace the paper gaskets as well as the torque rod bushings. I was able to remove layers of "metal protection" from the chassis with a putty knife. :rolleyes: You'll also get a chance to clean and lubricate the handbrake mechanism.
Frank Howard
'71 S4 SE
Minnesota