Propeller Shaft broken - repair advice or SEI?

MMWalleyeman

Recruit
Joined
Jul 27, 2014
Messages
3
I have a 1990 OMC 3.0L outdrive and the propshaft is broken off after hitting a rock. The shaft still spins in forward and reverse with no other damage visible. How hard is this to fix/replace the propshaft for a DIY 1st timer? Do availability of parts and difficulty cracking it open make a SEI drive the better option? I cant seem to find a lower on craigslist. I appreciate and value your opinions.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The changing of the shaft should be done by an experienced mechanic.
The 3.0/ 2.3 Cobra lower unit is smaller than the V-6/ 8.
So if you do find one make sure it's the right size.
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
The 3.0/ 2.3 Cobra lower unit is smaller than the V-6/ 8.
So if you do find one make sure it's the right size.

1990 3.0 lower *should* be same physical size as V6 V8. The 13 spline propshaft lowers on the 4 cylinder setups was only 1986-89 I think...
 

MMWalleyeman

Recruit
Joined
Jul 27, 2014
Messages
3
Thanks for your input. So the propshaft splines are the only difference. No big deal since i need a prop too. I may end up going with the SEI but I did find a deal on a full outdrive from a '87 V8 with a prop. I cannot find the chart and I don't have the book. Will this lower fit my 3.0L? Howard , your "should" quote concerns me.

I can then sell the upper since it has the specific gears and useless to me and maybe have a working lower for 100 clams when all is said and done. Thanks in advance!
 

Idlespeedonly

Senior Chief Petty Officer
Joined
Jun 30, 2011
Messages
779
It will physically fit, But the gear ratio will be way off. And I dont think you will be able to overcome the difference with a different prop.


----------------------------------------------------------------------------------------------------------------------------------------upper------------------- lower
[FONT=Arial,Helvetica,sans-serif]GMC 2.5 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]GMC 3 Litre before 1989[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:18[/FONT]​
[FONT=Arial,Helvetica,sans-serif]13:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 3 Litre since 1989[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:21[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 4.3 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:19[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 5 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:17[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 5.7 Litre Cobra / King Cobra before 1988[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:16[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 5.7 Litre Cobra / King Cobra after 1988[/FONT]
[FONT=Arial,Helvetica,sans-serif]24:29[/FONT]​
[FONT=Arial,Helvetica,sans-serif]17:21[/FONT]​
[FONT=Arial,Helvetica,sans-serif]GMC 554 or 502 King Cobra after 1988[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:17[/FONT]​
[FONT=Arial,Helvetica,sans-serif]17:20[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 2.3 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:21[/FONT]​
[FONT=Arial,Helvetica,sans-serif]13:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 351 King Cobra after 1992[/FONT]
[FONT=Arial,Helvetica,sans-serif]24:29[/FONT]​
[FONT=Arial,Helvetica,sans-serif]17:21[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 5 Litre or HQ 5 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:18[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 5.8 Litre[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:16[/FONT]​
[FONT=Arial,Helvetica,sans-serif]14:26[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 7.5 Litre King Cobra before 1988[/FONT]
[FONT=Arial,Helvetica,sans-serif]21:17[/FONT]​
[FONT=Arial,Helvetica,sans-serif]17:30[/FONT]​
[FONT=Arial,Helvetica,sans-serif]Ford 7.5 Litre King Cobra after 1988[/FONT]
[FONT=Arial,Helvetica,sans-serif]24:29[/FONT]​
[FONT=Arial,Helvetica,sans-serif]17:20[/FONT]​
 
Last edited:

MMWalleyeman

Recruit
Joined
Jul 27, 2014
Messages
3
Thanks Idle. That is the chart I am looking for...I looked everywhere! The 1st column is the upper and the 2nd the lower. As I said, I will only use the lower and they have the 14:26 gear set (except the 2.3L and the Kings) so I am good to go. I can put the 5.0L lower on my 3.0L upper.
Thank you all for your help peeps!!!
 
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