desert_rat
Recruit
- Joined
- Jul 12, 2011
- Messages
- 3
Ok so I read through all related posts and no help, contacted two local professionals who could make no sense of it, and have done quite a bit of research into stuck props to no avail. Here goes.
Dealing with 1997 Volvo Penta DP-D1 drive with A4 aluminum props. Forward prop is stuck but is NOT welded to shaft (slides easily for roughly 4" before stopping cold, no drag at all for first four inches). Backed boat (28', ~7500lbs) into underwater rock at idle, engine stalled out.:facepalm: Pushed boat off rock, started it, drove at idle back to pier (one hour plus) to remove from water (no docks). Both props pretty chewed up. Removed cone, rear prop, nut, all came off extremely easily and lots of silver anti-seize covering splines. Forward prop, once nut removed, slid back four inches with zero resistance, then stops cold. Having never removed these props before (new boat to me), looked at the front of forward prop to see if there was a circlip holding things on, or keyway, or whatever. None of that. However (this is the really weird bit), the forward prop has splines at the front of the prop.
I have the replacement prop, Volvo Penta A4 854777, and it only has splines on the rear half of the prop. Checked with the local prop expert, he confirmed that these only have splines on the rear half. The stuck one has splines both at front and rear. Things that make you go hmmmm...
So here's the results of my brainstorming:
-The rear splines on the forward prop slide easily on the shaft splines, as they should. Then something runs into the shaft splines that stops the prop from coming off. This must be those mystery splines at the front of the forward prop, which should not be there, and are apparently not aligned with the rear splines (or shaft splines), so they must be separate sets of splines, not a continuous spline. But where did they come from? My uneducated guesses:
1. The prop was rebuilt and the guy accidentally put two sets of splines on (installed splines, flipped it over, installed more splines); the forward set never engages the shaft splines, and after the prop was installed, they turned within the prop and are out of alignment with the shaft splines, interfering with removal. (I know this is far out, but I am really reaching for answers here).
2. Something from further forward in the lower gear unit slid back into the prop due to damage from impact. Something with splines. Needle Roller Bushing perhaps? It looks like it has splines in this (following) exploded view and is just forward of the forward prop, though it looks like the thrust washer should prevent it from getting inside the front of the prop.
Exploded view:
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7749309-44-10821.aspx
3. Poseidon hates me, and this is my inexplicable punishment.
Since I already have the replacement forward prop (a set came with the boat, but I hadn't replaced the front prop because I hadn't previously gotten around to ordering the nut removal tool) I am strongly considering just cutting the old one off with a skinny wheel and being done with it. However, if that mystery spline deal is something important from forward in the lower gear unit, I don't want to ruin it if at all possible. In all reality, it looks like it is actually a part of the prop. Could it be the needle roller bushing or inner ring (parts 33 and 34 in diagram)? Is that even possible? Have I enetered the Marine Twilight Zone???
Thanks for any help or advice you can offer.
Dealing with 1997 Volvo Penta DP-D1 drive with A4 aluminum props. Forward prop is stuck but is NOT welded to shaft (slides easily for roughly 4" before stopping cold, no drag at all for first four inches). Backed boat (28', ~7500lbs) into underwater rock at idle, engine stalled out.:facepalm: Pushed boat off rock, started it, drove at idle back to pier (one hour plus) to remove from water (no docks). Both props pretty chewed up. Removed cone, rear prop, nut, all came off extremely easily and lots of silver anti-seize covering splines. Forward prop, once nut removed, slid back four inches with zero resistance, then stops cold. Having never removed these props before (new boat to me), looked at the front of forward prop to see if there was a circlip holding things on, or keyway, or whatever. None of that. However (this is the really weird bit), the forward prop has splines at the front of the prop.
I have the replacement prop, Volvo Penta A4 854777, and it only has splines on the rear half of the prop. Checked with the local prop expert, he confirmed that these only have splines on the rear half. The stuck one has splines both at front and rear. Things that make you go hmmmm...So here's the results of my brainstorming:
-The rear splines on the forward prop slide easily on the shaft splines, as they should. Then something runs into the shaft splines that stops the prop from coming off. This must be those mystery splines at the front of the forward prop, which should not be there, and are apparently not aligned with the rear splines (or shaft splines), so they must be separate sets of splines, not a continuous spline. But where did they come from? My uneducated guesses:
1. The prop was rebuilt and the guy accidentally put two sets of splines on (installed splines, flipped it over, installed more splines); the forward set never engages the shaft splines, and after the prop was installed, they turned within the prop and are out of alignment with the shaft splines, interfering with removal. (I know this is far out, but I am really reaching for answers here).
2. Something from further forward in the lower gear unit slid back into the prop due to damage from impact. Something with splines. Needle Roller Bushing perhaps? It looks like it has splines in this (following) exploded view and is just forward of the forward prop, though it looks like the thrust washer should prevent it from getting inside the front of the prop.
Exploded view:
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7749309-44-10821.aspx
3. Poseidon hates me, and this is my inexplicable punishment.
Since I already have the replacement forward prop (a set came with the boat, but I hadn't replaced the front prop because I hadn't previously gotten around to ordering the nut removal tool) I am strongly considering just cutting the old one off with a skinny wheel and being done with it. However, if that mystery spline deal is something important from forward in the lower gear unit, I don't want to ruin it if at all possible. In all reality, it looks like it is actually a part of the prop. Could it be the needle roller bushing or inner ring (parts 33 and 34 in diagram)? Is that even possible? Have I enetered the Marine Twilight Zone???
Thanks for any help or advice you can offer.
