I think you may just be a victim of overtightening the screws. I know its easy to do and I'm not being critical. Start over with a new housing and spur then all new orings. I've been keeping all the shims where the manual recomends and haven't had a problem. Just use lots of grease on the orings and grease the whole gasket both sides. Take your time tighten the screws evenly and you shouldn't have an issue.