Rich Shertenlieb, one half of the former “Toucher and Rich” morning drive program heard on the old rock WBCN-FM and then on sports talk WBZ-FM, “98.5 The Sports Hub,” will be back on the Boston airwaves “soon.” Shertenlieb exited WBZ-FM last November after his professional relationship with partner Fred Toucher fell apart and Toucher re-upped with Beasley to continue hosting the “98.5 The Sports Hub” morning show. Now, iHeartMedia cuts ties with the classic rock WZLX-FM, Boston morning team of Pete McKenzie and Heather Ford and installs “The Rich Shertenlieb Show.”