Is it possible to correct this problem without rebuilding the transmission? I had the transmission rebuilt a year ago and that’s when it started slipping. The transmission is a General Motors transmission
First you need to describe slip. People tend to describe all sorts of different things as “slip.” So describe in detail exactly what happens between 1st & 2nd gear.
You also might want to clarify how a GM transmission gets into a Volvo.
You might also want to tell people what year your Volvo is, how many miles are on it, what it was doing before it was rebuilt a year ago, and what you have done in terms of keeping up with maintenance.
You might also clarify why you have been driving for year on a “slipping” rebuild rather than immediately bringing it back to the rebuilder/installer.
Is your check engine light on?