What to check in lower unit?

Dm82

Seaman Apprentice
Joined
Jul 30, 2008
Messages
31
Hello all again. Seeing as I have gotten so much good advice from other post I am going to shoot another question out to you guys. I have a 68 Johnson 100 hp (v4tl-14b) and recently changed the oil in the lower unit. Now when I changed the oil it came out out kind of milky white. From reading other post here I see that this is not a good thing. So I did put oil back in it but that was just to hold it over until I can tear it apart. That project is going to today so I just wanted to ask what to look for when I get it open. I am going to replace the upper and lower seals, but is there anything else I should look at? Thanks again.
 

jasper4564

Recruit
Joined
Apr 15, 2009
Messages
1
Re: What to check in lower unit?

change the nylon washers in the fill/drain plug openings , sometimes these will allow water inside if they are not sealing off properly
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: What to check in lower unit?

That is an easy one to reseal. There are the bearing carriers (and seals) on the prop shaft and drive shaft. Easy to remove and replace the seals. I believe there are o-rings around the bearing carriers as well as the seals for the shafts. No need for any further dis-assembly.

Those and the fill plugs are the only openings into the gearcase.

You will have the water pump apart to access the drive shaft seals, so needless to say, address any issues with that at the same time. There is an innocent looking foam seal on top of the water pump cover. It won't run with the hood on if that seal is bad. I always replace it.
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: What to check in lower unit?

You may want to get the LU pressure/vacuum tested to see where the leak is occurring. But more than likely, the reseal kit will be necessary.

MAS
 
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