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Lower unit lubrication process

lamarkeiko

New member
I just got a used boat with a 15 HP Johnson Model J15RCOB. I believe the motor is a 1985. I'm looking forward to taking the boat out, but I believe I should change oil in the lower unit first. I know where the oil level plug is. I removed the screw, and could not see any oil up to the hole. I also know where the oil drain plug is down below. I do not have an owners manual for any guidance. Is it just a simple process of just removing both upper and lower plugs and letting the oil drain on its own with the motor in an upright position? Once drained, what is the procedure for filling, and what type oil?
Thanks for your input.

Lamar
 

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Remove both plugs to drain the oil.-----------Fill from the bottom till oil shows at the top ( level hole )------------Then install the top plug. Remove filling device and install bottom plug.--Use outboard gear oil.------Make sure you have one gasket on each plug.-----Unless you know for sure how old the waterpump impeller is , you should install a new one.---Impellers only last so long.
 
Thanks for the information. My next question is how much gear oil do I need to purchase, and does it come with a special tube to insert into the drain hole for filling? Also, as for replacing the water pump impeller, I could use some help in explaining this process. That I assume should be done once the gear oil has been drained.
Lamar
 
If you do not know the condition / age of the impeller you should replace it !---------The motor does not have any provision for shutdown in case of overheat.------------The only thing that happens is you will notice the motor slowing down due to seizing of pistons.----Then it will be an expensive process.----------Most folks learn a lot about motors the hard way, and that is by lightening the wallet.
 
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