Replaced complete driveshaft / u-joint assembly on a Volvo DP-SM outdrive. Put on the water, ran great except for overheating at midrange rpms. Figured we must have forgot to tighten the plastic nipple nut and unit was sucking air when out of water. Pulled outdrive back off and yeah it was just hand tight. Tightened nut until saw threaded plastic nipple coming through. It was getting very tight and almost appeared to start stripping. At a glance looked like square portion on other side of housing would seat the way it was lined up. Put everything back together and there is still water leaking from the back of the housing (when on water muffs). Hard to tell but I guess it still isn't seated properly. I'm positive is more than tight enough and sealed between the housing and outdrive. My question is what is the purpose of the drain hole on the nipple? if I can dab some adhesive/sealant from the port on the back of the drive (4 bolts holding plate - can see hole with inspection scope) using a long screw driver. The nipple is only a couple years old, hose clamp tight on the back side, no visible cracks inside and Im sure it's sealed on the inside, so if I could seal the drain hole, there shouldn't be a way for water/air to escape??? What is the drain hole in middle bottom of plastic nipple purpose? Just really don't want to have to pull drive again, gimbal came out on shaft last pull and this last install on new bearing, we had a real tough time getting outdrive on - new shaft / bearing super tight. Thanks.
