Season Ending Early - Outdrive Issue


G

gustaf

Member
Well, it looks like I'll be pulling my boat about a month early. Beautiful weekend here in the northeast this past weekend. We were headed out of our home port Saturday morning, were on plane for a couple of minutes and then all of a sudden I felt the power drop out and saw one of the motors bouncing off the rev limiter. Turned around and limped back on one motor.
Looks like something went inside the drive (Volvo Penta DP-SM) because there is almost no resistance when shifiting. Once we were tied up on our mooring, I jumped in the water and removed the cover on the drive to make sure it wasn't something easy like a bad cable (doubted it because I changed all of them 2 season ago) or cable connection but unfortunately everything was moving as it should and actuating the shift mechanism as it should. Looks like I'll be rebuilding a drive in the off season.
Anyone ever heard of a VP drive doing anything like this?
 
Have you checked the prop hub? When the engine over revs, its possible the hub is spinning.
 
Unfortunately not the prop hub either. And the engine over-rev was due to the drive dropping all load off the engine.

Admin - I think that may be what gave up. I can turn the props by hand easily regardless of the gear selector being in neutral, forward or reverse and it all feels good so it does not seem like anything grenaded within the drive - fingers crossed.
 
Moving easy in/out of gear does sound like drive to me. If it was the coupler there would be some kind of drag. Get the motor running and look at the input shaft and see if its turning. If it is then its in the lower drive because your not overheating
 
AllDodge - totally agree that its the drive. There is a splined sleeve within the drive that is meant to be a bit of a sacrificial item should you hit something with the props (which I did not). My guess is that it may have given up for some reason but I'll know more once I get it out of the water and the drive apart.
I did take a look at the coupler right after it happened and it looked fine and there were no bits of rubber or rubber dust in the area. Also, when running, i could see the driveshaft spin.
 
Quick update on this - so after a lot of effort trying to get the drive apart, I gave up and dropped it off to a guy who does Volvo drives. He was able to get it apart (heavy corrosion around the studs) and it ended up that the upper shaft actually broke just above the coupler. He's never seen anything like this. Once he got the shaft replaced, put it back together and pressure tested it, he found that the case had cracked near the lower portion of the upper gearset as well. The thought is that when the shaft broke and the engine was bouncing off the rev limiter for a couple seconds, it may have cause a bit of wobble and the case couldn't handle it.
Got a replacement upper case and we are all back together and ready to remount on the boat once I paint things up.
 
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