Wings went through some changes in Season 7. The most obvious was the departure of Thomas Hayden Church as Lowell Mather. He appears in just one episode where he is written out of the show for the remainder of the series. He is replaced by a new mechanic named Budd who appears frequently in the first half of the season but less and less in the second half. Apparently, the producers came to see him as a mistake because he is dropped altogether for Season 8.
Outside of the cast changes already mentioned, Season 7 of Wings stuck to a formula similar to prior seasons and was largely successful. Joe, Helen, Brian, and Casey all occupy the same house thanks to a fire and the situation was milked for as much as the writers could get out of it. This year may not be at quite the level that we saw from Wings - The Sixth Season, but there are plenty of laughs and it makes for an enjoyable time.