Out drive damage.

gas man

Cadet
Joined
Jul 14, 2014
Messages
15
Hit a submerged rock. Moving at low idle speed in 20 ft of water when depth finder alarm went off and bam hit something hard. Pulled back on the throtle to take it out of gear. When I settled down I put the boat back in forward gear it did nothing but spin. First thought I threw the prop. Kept engine running (it never cut out) and lifted the drive to check it out. Prop still there but can't get it to go in gear. Messed up something inside big time, right? I am hoping I can get some ideas as to what might have happened from the least worse case scenerio to the worse case scenerio before taking it to a shop where they'll tell me I need a new outdrive. Any ideas? Much appreciated.
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,684
The prop might be slipping on it's rubber hub.
Put a mark on the rubber hub and prop and see if the relationship between them changes when you put it into gear and "spins".
Also, it's not a good idea to tilt the drive all the way up when it's running. It's hard on the u-joints.
Good luck.
 

Starcraft5834

Lieutenant Commander
Joined
Jun 2, 2013
Messages
1,677
what kind of drive do have? A1 lower units can be had for approx $800. pull it apart and look............
 

ktbarrentine

Lieutenant
Joined
Dec 12, 2011
Messages
1,296
Yes, please tell us the type of drive, ser number, year, etc. I'm putting my money on it being a pre-genII alpha-1 drive, and you broke your vertical drive shaft at the O-ring groove just below where it enters the upper half of the drive (yes....just a guess, but on the limited info given, that's all I will say). What did your engine temp do when you lost propulsion? If it went up, then your impeller quit turning (when the vert shaft quit turning).
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
+1, I'm with kt. If you spun the prop, it will still turn when you put it in gear, if you broke the vertical driveshaft it will not. Drain the gearhousing (lower) and remove it. If the shaft broken, just take that part in for repair. Do the impeller while you are at it.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
+1, I'm with kt. If you spun the prop, it will still turn when you put it in gear, if you broke the vertical driveshaft it will not. Drain the gearhousing (lower) and remove it. If the shaft broken, just take that part in for repair. Do the impeller while you are at it.

+2 on breaking your vertical shaft. Unfortunately I would have to disagree as to the amount of damage you will find if that is the case. I broke mine a few years ago and it also ended up trashing the gears in the upper. I would suggest taking the top cap off and looking to see if there is any visible damage.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Actually, my memory was not as good as it should be. ;) On mine, the upper shaft broke and then it trashed the top of the lower shaft. Bottom line, I ended up replacing the entire outdrive with an aftermarket Sterndrive Engineering unit. Maybe you'll get lucky! Here's what broke on mine:

DSCF0303.jpg
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
A spun hub would leave you with some propulsion. 3 things I can think of are vertical shaft, upper gears or coupler splines.
 

scatgo

Petty Officer 1st Class
Joined
Jul 13, 2014
Messages
362
U joint yoke was broke where it went into the out drive on my boat.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
U joint yoke was broke where it went into the out drive on my boat.

That's a new one. Never heard of one breaking there. Where exactly did it break? On the picture below - did the shaft itself break? Or perhaps the ears where the u joint attaches? Curious!

460201.jpg
 
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gas man

Cadet
Joined
Jul 14, 2014
Messages
15
It is a1988 Alpha 1 outdrive. Not sure of the serial number. Engine is MerCruiser 120, 2.5L. Took the prop in to get fixed and unfortunately the hub was fine. Guess it's time to get my hands dirty. Is it an easy fix or should I take it to a mechanic? How much $$ are we talking?
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
It all depends on what is broke. Pull the drive. It is easy. Put it in Forward, remove the 6 nuts and the trim ram pin. The drive should just slide off. Once it is off you can look through the gimbal bearing at the coupler splines to see how they are. You can take the top cap off the drive and look at the gears. If they are fine then split the drive and have a look at the vertical shaft (make sure the lube is drained). All this should take less than an hour even if you have never done it.
 
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