Prop seal replacement...

[indianriverbound]

I have twin 1999 Merc 200 EFI's that I need to replace the prop seals in. Although I have never done it in an outboard engine, I do have experience replacing engine seals, just not in anything that would be run underwater. Is there any words of advice in doing this, any pointers that would help with the seal? I have been told to apply locktite to the outer seal, does this sound correct or is there any other lubes or sealers I should use? Any advice would be welcome.

 

[oldman570]

Re: Prop seal replacement...

I never use locktite on seals, I just use a vary thin coat of thr red RV silicon on the outer surface and lube tha rubber with a coating of LU oil when placeing it on the propshaft. The O ring seal I use the LU oil on also. Make sure you put the propshaft seals in the housing so one seals the LU oil from getting out and the other is reversed and keeps the water frome getting in if so equiped. A pressure /vacum test of the LU should be preformed to varify that those seals are bad, and not the driveshaft seals, as they can leak water into the gearcase also. The drain plug and vent plug seals should be replace for the same reason. JMO
Oldman570

 

[indianriverbound]

Re: Prop seal replacement...

Thank you 570, that helps alot. I just bought the boat last summer and noticed at the end of the season I had gear lube starting to run down the foot and drip from the lower unit on one engine. It did not have a milky color to it so I suspect that the strain from me running the boat all summer after it sitting for a number of years may have caused a dry rotted seal to fail at the end of the season. On one engine I also have the bushings in the swivel bracket that are worn out. You can grab the foot of the motor and see the play if you lift up and down on it. I ordered the bushings and found out that they are made out of a plastic or fiber material and am debating if I really want to replace them. I know I should to keep everything status quo but it will require removal of the engine from the mount bracket to do so. I do have the means to do this but it would require disconnecting the shift rod from the top of the engine since it runs down thru the swivel arm. My Selco manual does not show how to do this. Can this be done rather easily or would I be better to just leave the entire repair be? I know the swivel bracket has been discontinued for my engine and if I did find one the cost would be about $1000. I do not want to do this costly repair in the future.

 

[oldman570]

Re: Prop seal replacement...

Before doing the prop shaft seals, do the pressure test to be sure that it is in fact LU lube. If the motor is running rich it could just be unburnt fuel draining from the exhaust on the motor. If the drainage looks dark and smells like unburnt fuel, this could be the trouble. Is the LU grease milky colored inducating a water intrusion, or is there warter in the LU when you check it after it has set for a day? This could save you some time an $$$. As for the steering tube bushings, I would go ahead and replace them when time permits. You can go to http://boatinfo.no/lib/library.html where you can find a manual for you motor if you do not have one. It should tell you what needs to be done to change the tube bushings, and other info on your motor. You have to slide the little slot button under the manuals to get the one you need. JMO
Oldman570

 

[indianriverbound]

Re: Prop seal replacement...

Now that manual site is GOLD!!!! Thank you again 570!!!!