Did you indicate the bellhouse, before slaming the tranny in? that is to say; can you say with surety that the crank and the tranny are on the same centerline?
This says you have multiple issues; 3 by my count.
Yes, everything was lined up before installing about a year ago. Bellhousing is a stock piece.
This issue is popped up about a month or so ago shortly after a gear change, which has led me to suspect that the increased driveshaft speed is making a worn tail bushing or slight pinion angle misalignment more obvious.
As for the issue described, all of the symptoms popped up at once. Sorry if it seems like three issues; hard to describe these things sometimes without someone else actually feeling them.
