OMC cobra 1989 outdrive u joint issues.

Capt. Zack

Seaman Apprentice
Joined
Feb 18, 2018
Messages
33
1989 omc cobra outdrive u joint not turning

I had the outdrive off the boat and was ready to put it back on after the motor was installed. I found that the u joint shaft will not turn. It moves about 1/2" only. The out drive has been off the boat for about a year while I rebuilt the motor. The motor is done and in the boat. The u joints and the shaft has not corrosion or rust and the joints are well lubed. There is no indication of water getting inside the bellows. Nice and clean and dry. The person I bought it from said it shifted well prior to motor being hydro locked.

Any information regarding what I may be looking at here and how best to move forward to find out what the cause is would be appreciated. There was a clamp laying in the bottom of the drive next to the shift rod. It does not move by hand. Have not tried to force at all. The oil is clean and the prop turns fee..

Thanks in advance for your help and suggestions
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,070
Is the drive in neutral? Neutral is the center position on the shift rod, it moves up and down to selected the gear positons. Try to get someone to turn the prop shaft while you try to move the shift rod through the FWD, Neutral and Rev positions.
Also keep in mind that if you are trying to turn the drive shaft, even with it in neutral you will feel drag on it from the raw water impeller in the upper gear housing but it will still turn.

post up a few pix of what you got/
 

Capt. Zack

Seaman Apprentice
Joined
Feb 18, 2018
Messages
33
Thank you for the response. The shift rod appears to be all the way up. The prop spins freely nice and quiet. Is it possible that the water pump impeller could be stuck on the other end? causing the u joint shaft not to turn. Re checked the oil to see if it shows any water or metalic residue. It is clean..

Please any ideas will be appreciated
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,070
If the shift rod is up all the way the prop should lock because its either in FWD or REV, I forget which....the only position where it should spin free is in Neutral, in the center between Fwd and Rev....
 

Capt. Zack

Seaman Apprentice
Joined
Feb 18, 2018
Messages
33
I pulled the water pump cover and rubber impeller off the outdrive and the u joint shaft turns as it should. It was corroded and would not turn. The impeller shaft is part of the u joint shaft. Everything works as it should now. Thanks for the input.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,070
Good glad you had a good out come. The Cobra impeller is very easy to replace, just make sure to get that o ring gasket in the groove of the housing.
 
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