Another prop slipping thread

[beech2000]

Drive pulled off hours ago.
Inspection of OD spline - Normal
Inspection of Coupler splines with flash light - Normal
Inspection of Coupler Rubber - Unknown

Looks like I have a mystery novel on my hand. I didn't have the chance to nose dive into the engine bay to inspect the rubber. That's the only thing left.
I wonder......
What if..... while at high power under extreme load the engine momentary died for a split section. Could it cause the dog gears to release?

 

[ROY WILLIAMS]

I was the rusted in the bellows U JOINTS drive shaft in water .. inspect the gasket/bellows ...

 

[beech2000]

Rust shown on ujoints is from previous tear in the gasket. All is dry this go.
Could an ignition interruption cause is to go out of gear while underway with high power?

 

[ROY WILLIAMS]

Rust shown on ujoints is from previous tear in the gasket. All is dry this go.
Could an ignition interruption cause is to go out of gear while underway with high power?

the cable gear in the outdrive .. I was the cable did the rod inside that cable . https://www.wd40.com/products/industrial-size/
the bellows inside the moly grease did the shifter part ...
I was take out the fall outdrive and inspect it and cleaned the bellows and do the moly grease and the gasket ..u joints shaft cable shifter
I was the gasket and the silicone grease nice ..

 

[markhodges78]

I bet it's your forward gear.
Do this
Put it all back together go out on the water. Unhook lower shift cable push in on the cable to engage forward gear.
Have some one increase throttle while your pushing in on shift cable until the problem starts.
When the problem starts take notice Do you feel a ratcheting in the cable?
If so that's the dogs on the gears letting go

 

[ROY WILLIAMS]

I bet it's your forward gear.
Do this
Put it all back together go out on the water. Unhook lower shift cable push in on the cable to engage forward gear.
Have some one increase throttle while your pushing in on shift cable until the problem starts.
When the problem starts take notice Do you feel a ratcheting in the cable?
If so that's the dogs on the gears letting go

yes that throttle shifter , and the out of that water boat ,, is the fwd , neutral , and the rev of that prop ... fwr left prop locked up ...neutral spin it good no noise , and the rev prop right locked up ...
did several times ....
also the engine ignition switch of the shift cable is doing the YouTube ..

 

[beech2000]

I bet it's your forward gear.
Do this
Put it all back together go out on the water. Unhook lower shift cable push in on the cable to engage forward gear.
Have some one increase throttle while your pushing in on shift cable until the problem starts.
When the problem starts take notice Do you feel a ratcheting in the cable?
If so that's the dogs on the gears letting go

Thank you!
Would there be metal in oil associated with a failed forward gear or dogs?

 

[ScottinAZ]

Thank you!
Would there be metal in oil associated with a failed forward gear or dogs?

yes, if you see metal chunks in the oil, its not a good thing. IF the dogs or gears are failing, that metal has to go somewhere, and into the oil as chunks is where it usually goes. I have magnetic drain plugs on my outdrive, top and bottom. Makes it easy to do a quick health check on the drive when you pull the plugs. Paste, or small filings are "normal", chunks not so much.....

 

[kenny nunez]

Once the dog is locked in any gear there is no way it would slip. I am bettering on the drive coupler. Especially after the propeller has been ruled out. Full power starts pulling people really puts a lot of strain on the coupler.
Upper or lower gears do not “repair themselves “ after the teeth are gone.
Alpha 1s can hold up to at least 400 hp as long as they are maintained and have not struck submerged objects.
The boat that the you were using is it her 190 BR in your signature?

 

[QBhoy]

That’s some power from a stroker kit. What else have you done to it ? Weirdly low rpm number you’ve said there, for making its peak power. Normally it’s making its best power upwards of 4500 rpm or so, I always assumed. Love to hear more about the build. That low in the rpm for making power is usually more familiar with forced induction and or diesel engines perhaps.

 

[beech2000]

Once the dog is locked in any gear there is no way it would slip. I am bettering on the drive coupler. Especially after the propeller has been ruled out. Full power starts pulling people really puts a lot of strain on the coupler.
Upper or lower gears do not “repair themselves “ after the teeth are gone.
Alpha 1s can hold up to at least 400 hp as long as they are maintained and have not struck submerged objects.
The boat that the you were using is it her 190 BR in your signature?

I have the lower unit apart and nothing found. I'm back to the coupler which requires pulling the engine.

 

[beech2000]

That’s some power from a stroker kit. What else have you done to it ? Weirdly low rpm number you’ve said there, for making its peak power. Normally it’s making its best power upwards of 4500 rpm or so, I always assumed. Love to hear more about the build. That low in the rpm for making power is usually more familiar with forced induction and or diesel engines perhaps.

The Engine is a high compression, ported and cammed street engine in a boat. (Never Good) So much so that I was forced to install Vortec SBC Rhodes Roller lifters that bleed off at low RPM to prevent the suction of water ingestion for marine use.
Even funny sounding when lid is up. Dyno test guy even remarked that not a good choice for a boat. That said.... It's provided great service up until now. 7 years in fact. Back to thinking a bad coupler is source of self inhibited troubles.

 

[beech2000]

Once the dog is locked in any gear there is no way it would slip. I am bettering on the drive coupler. Especially after the propeller has been ruled out. Full power starts pulling people really puts a lot of strain on the coupler.
Upper or lower gears do not “repair themselves “ after the teeth are gone.
Alpha 1s can hold up to at least 400 hp as long as they are maintained and have not struck submerged objects.
The boat that the you were using is it her 190 BR in your signature?

Yes... here is a video short video of the little boat awhile back. I've since added a ski tower

 

[Scott06]

I have the lower unit apart and nothing found. I'm back to the coupler which requires pulling the engine.

Yes if you looked at the dog teeth they are back cut so under load from the prop it cant pop out of gear… and this is why they use the shift interrupt system.

at least you have narrowed it down to the coupler. was the alignment ok when you took it off ? You don’t rally have to fully remove the engine. If you have a chain fall and beam in the garage just lift it up and forward enough to get the flywheel cover off. Not sure of the bravo coupler fits or if it is beefier. Physically it looks bigger around the hub

what cam is in the engine ? rhoads lifters is a good way to go to tame it some. They are known for being noisy. I have a sea ray 200 sport added a krypt tower to it really helps big guys like me get up on the wakeboard

 

[QBhoy]

Yes... here is a video short video of the little boat awhile back. I've since added a ski tower

That sounds very very similar to my boat, at idle speed there. I have a cam in my v8 mpi 18ft. Yours is the closest sounding I’ve heard to mine. Definitely the cam makes that distinctive throbbing noise at low rpm. Mine as a result is quite weak from low rpm, if I run a pitch of prop that gets the use of the power at the top of the rpms.

 

[Scott06]

That sounds very very similar to my boat, at idle speed there. I have a cam in my v8 mpi 18ft. Yours is the closest sounding I’ve heard to mine. Definitely the cam makes that distinctive throbbing noise at low rpm. Mine as a result is quite weak from low rpm, if I run a pitch of prop that gets the use of the power at the top of the rpms.

You might benefit from Rhoda lifters very commonly used in us to tame wild camshafts by bleeding off duration at low
Rpms

 

[beech2000]

at least you have narrowed it down to the coupler. was the alignment ok when you took it off ?

what cam is in the engine ? rhoads lifters is a good way to go to tame it some. They are known for being noisy. I have a sea ray 200 sport added a krypt tower to it really helps big guys like me get up on the wakeboard

Alignment shaft slides in and out effortless. So yes.
Many years ago on the roller cam choice we chose. Again it was built for our Camero but ended up using it for the SeaRay. The engine is 2000 5.7 4 bolt Vortec SBC from a 3500 truck with a stroker kit from Summit. We built it for street / strip.
We chose to purchased a turn key LS engine with EFI and Air Conditioning from Summit for the Camero.

 

[beech2000]

Well I had the chance to pull the engine yesterday for inspection of the coupling. Nothing obvious found.
Will the heavy duty big block coupling work on my Vortec? I found one for just a little bit more than mine.

 

[alldodge]

What do the splines inside the coupler look like?

 

[tank1949]

Well I had the chance to pull the engine yesterday for inspection of the coupling. Nothing obvious found.
Will the heavy duty big block coupling work on my Vortec? I found one for just a little bit more than mine.

water over damn... With OD installed, and with a buddy and a vice grip, stop motor from turning (best way) while you attempt to move prop with a 2x4" If anything moves, pull prop and take to shop and pray it needs repairs and not coupler. I had similar problem with a MC/Proline