Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-03-2019, 09:22 PM   #1
Lt. JG
 
Join Date: Apr 2019
Posts: 27
Thumbs down Hit outboard leg on rock

Hi Everyone,

I'm gutted to write this but hit the leg at 70% speed today on a rock that wasnt marked on the lake. Its an Alpha One Gen2 leg on a Mercruiser 4.7 1997 LH Engine...

The engine appears to be fine however will cut out when I try to put it in gear. Haven't had a chance to take the prop off yet and there appears to be a chunk missing from the bottom of the leg (fin). With the engine off and throttle in gear the prop moves in both directions (including reverse) with a clicking sound in one direction.

Could anyone please recommend how to go about diagnosing and see what I need to do? I'm hoping its just a sheerpin and prop replacement.

Thank you in advance.
(insert crying here)
Attached Thumbnails
20190803_213752.jpg   20190803_213900.jpg  
__________________

fester is offline   Reply With Quote
Old 08-03-2019, 09:47 PM   #2
Admiral
 
Phillbo's Avatar
 
Join Date: Mar 2012
Location: Lake Powell
Posts: 1,188
Default

The skeg and the prop are easy fixes. It's your comment "The engine appears to be fine however will cut out when I try to put it in gear" that has me concerned. If by that you mean the engine stalled when you put it in gear you could have done internal damage to the outdrive.

For the skeg : https://express.google.com/u/0/produ...RoC6bUQAvD_BwE
__________________

Phillbo is offline   Reply With Quote
Old 08-04-2019, 12:37 AM   #3
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 7,267
Default

The drive must in the lowered position then in forward try turning the prop in both directions, it should only turn one way. Now put it in reverse and it should only turn the other way. Remove the prop and start the engine and see if it shifts into forward and reverse.
__________________
1997 2400 SCR
5.7 Vortec / Bravo 2
Mike
mmwjr is offline   Reply With Quote
Old 08-04-2019, 01:34 AM   #4
Commander
 
jrsick's Avatar
 
Join Date: Oct 2011
Location: Chesapeake, VA
Posts: 417
Default

With engine off and in neutral, spin the prop fast and see if it wobbles. Drain the leg gear oil and check the oil and plug for metal chunks.
If it passes the tests Mike recommends, prop spins true, and the gear oil is clear, next step is to remove the drive cap and take a look at the upper gears.
I would check the engine coupler also, but that wouldn't account for the engine stalling. Also check that the shift shaft coupler is still seated properly.
I'm thinking best course now is to assume there has been gear damage and try to locate which gears.
You should have spun your prop hub during this incident, that's one of reasons for the hub.
__________________
2006 Bayliner BR205
A1 Gen 2 1.47
5.0 carb engine
jrsick is offline   Reply With Quote
Old 08-04-2019, 03:11 AM   #5
Admiral
 
Phillbo's Avatar
 
Join Date: Mar 2012
Location: Lake Powell
Posts: 1,188
Default

Quote:
Originally Posted by mmwjr View Post
The drive must in the lowered position then in forward try turning the prop in both directions, it should only turn one way. Now put it in reverse and it should only turn the other way. Remove the prop and start the engine and see if it shifts into forward and reverse.
Start with this....
Phillbo is offline   Reply With Quote
Old 08-05-2019, 03:45 PM   #6
Lt. JG
 
Join Date: Apr 2019
Posts: 27
Default Took the prop off

Thanks for the solid advice everyone.

We took the prop off today and it looks as if the middle pin has a wobble. I think the skeg hit the rock first and chipped off a bit into the prop.

With the engine off, it does rotate in both directions regardless if its in forward or reverse gear. Leg has a clicking sound when turn the prop in one direction. Unfortunately we got caught in torrential rain and couldn't diagnose further..

I'm praying its just the lower leg unit/prop. The bellow and seal around the transom/upper leg appear to be intact. Going try diagnosing again at the weekend with the engine on and prop off..

Hopefully this is something I can fix myself.. May even do a youtube video for any other poor soul who encounters the same problem.

If it is just the lower leg unit do you think someone with 0 mechanic experience can replace it or should I get a pro to do it? I'm guessing its just drain the gear oil, replace the leg, pump in gear oil from the bottom? I'm up for the challenge and learning experience but always think safety first.

Will keep you all posted and thank you again for all your advice.

The guy who rescued me from the lake had a funny acronym BOAT = Budget On Another Thousand #NeverForget
fester is offline   Reply With Quote
Old 08-05-2019, 04:02 PM   #7
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 7,267
Default

B.O.A.T. is commonly know as Break Out Another Thousand.

Replacing the lower unit is the same procedure as removing it to replace the impeller. Dain lube, unbolt (don't forget bolt under rear anode), remove. To install make sure lube seal is installed on outer wall the reverse the above. Note shifter has to be in reverse when removing and installing the drive.

The unit can be rebuilt but based on the damage I doubt it would same money over a new one. IMO don't get the aftermarket sterndrive engineering one to save money as many end up having them go bad although its under the three year warranty but you first have to return the bad one so you can loose a month in the exchange process.
__________________
1997 2400 SCR
5.7 Vortec / Bravo 2
Mike
mmwjr is offline   Reply With Quote
Old 08-06-2019, 03:24 PM   #8
Moderator

 
Join Date: Apr 2008
Posts: 4,480
Default

Doesn't the Alpha I have a Prop Hub? I thought it did. IF so, that should be replaced and should be what protects the gears from shearing when this occurs.
shrew is offline   Reply With Quote
Old 08-06-2019, 05:09 PM   #9
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 7,267
Default

Quote:
Originally Posted by shrew View Post
Doesn't the Alpha I have a Prop Hub? I thought it did. IF so, that should be replaced and should be what protects the gears from shearing when this occurs.
Yes it does but doesn't guarantee no damage will occur. From the sounds of it the prop shaft is bent as well.
__________________
1997 2400 SCR
5.7 Vortec / Bravo 2
Mike
mmwjr is offline   Reply With Quote
Old 08-08-2019, 01:19 PM   #10
Moderator

 
Join Date: Apr 2008
Posts: 4,480
Default

I can see how the prop hub won't protect the prop shaft if the hit is hard enough, but it should protect the gears. When a tooth shears, it sounds like a coffee grinder in gear.
__________________

shrew is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 07:22 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.