Yeah, the evening services went through that part of Sunderland too at one point.
Nearly sh!t a brick the first time it happened, not knowing the area at all then or being certain I was on the right bus (or indeed if it had changed its route completely and was going no-where near where I lived at the time).
Pretty sure at one point, the Sunday service was ran as two separate services. 638 Sunderland - Rickleton/Heworth and also between two points in Western Gateshead, effectively missing out the Wrekenton - Whickham section.
RE: Go North East