I have not personally replaced the seal with this method. I have always taken the front cover off. Having said that, there have been postings on this board detailing how they replaced the seal with the cover in place. I don't see any problems with this, except for the challenge of getting the old one out. I don't think the challenge is prohibitive and the procedure would save many hours of labour. Installing the new one is easily done using a sleeve to tap it in place.
