I have to agree that lack of throwout is a likely culprit.. in looking at his other posts, I see he's dealing with a '73 ES... so, a clutch _cable_ adjustment would be what's needed.

That said.. being a '73, in my experience, that later shifter linkage is more prone to wearing out than the earlier cars... I'm not very familiar with that linkage, but I'm guessing you want to hope that's not the problem.

I would check clutch adjustment first, then motor and transmission mounts.

Adam.. always post the year of your car... As we all know, Volvo made cars that look the same or similar for extremely long model runs, but... the fixins under the sheet metal often did change, and in some cases significantly.

Good luck with it!

--
-Matt I ♥ my ♂