I have IMCO lowers on my boat. I almost lost a prop when the nut backed off while I was running. My alarm went off when my drive oil got low. I stopped and raised the drive to find the prop barely on the shaft. I thought I had lost a prop seal. When I pulled the boat out and removed the prop, I found that my oil drain screw had come out and was gone!!!

Anybody ever heard of or seen anything similar happen?

My alarm definitely saved me a chitload of $$$.

Dean

That's not that uncommon...When you change your gear oil, you SHOULD run the boat on the hose & shift it a couple times & THEN retighten BOTH fill & drain plugs because VIBRATION WILL loosen them up a lot of times...Obviously you had a vibration from the prop nut NOT being properly "tanged" & torqued which vibrated the drain plug out...Your welcome.......

I thought I had everything tightened up properly. I had run the boat for about 11 hours when this happened.

Always retorque your prop after a short run. They almost always will be loose. Never had a drain plug fall out though.
Gary

Thanks for the help.

I had a prop come loose 2 weeks ago. Never felt it and it looks like there was no damage. Just baffled me how it could back off the lock nut and tang. I'll be checking the drain plug when I get home tonight!

Cord,
Mine was the same thing. No vibration or warning of any kind. If my drain plug hadn't come out to set off my alarm, I am confident it would have lost a prop...
Dean

I just happened to notice that it was sloppy on the shaft when I was checking the leading edge for nicks.

FYI, most common thing is finger tight prop nut after a few hours of running following prop install. This could cause slop on shaft resulting in metal fatigue, broken shaft or drive parts. Buy a torque wrnch and use it.
My $0.02
Gary