A few months after I purchased my boat (used boat) the starboard drive failed. It was determined that the stock cap failed at the bearing mount and sent shrapnel through the drive destroying it.
I replaced the stock caps with the billet type. This year the starboard drive failed again. This time a tooth broke off the top gear and almost blew the whole drive off the gimble.The billet cap held together although it was damaged beyond use.
The person that rebuilt my drive told me that I was lucky that the drive didn't break off altogether causing the boat to sink. Either way, the drives were destroyed but by using the billet caps am I removing a mechanical fuse? Breaking a drive is bad enough but sinking would really suck.