well when I pulled the cases apart I found that one of the rods that holds the gears had broke.. the one that is circled
well when i pulled the piece that was still in the case out it was all out of round .. I thought about getting a bushing and making it all work out I think that just getting a new case side will be better in the long run..
It's best to replace the cases in matched sets. They are machined as a matched set. People have had luck mixing, but sometimes core shift and slight differences in machining can cause binding in the gears.