1986 US Marine Force Shift Shaft Seal replacement

[10dknezevic]

Hi,

I'm new to iBoats! What a great resource! I don't have too much experience with outboards or boats, but I do have a ton of experience on cars, so I'm hoping that helps me with this issue. I have, what I believe is a 1986 or '87 US Marine Force 50hp engine. It's leaking lower unit fluid from the shift shaft seal. There was actually bits or brittle rubber falling off of it. Now, it looks a bit tricky to remove, so before I try, I was hoping someone could give me some direction. Any help is greatly appreciated!! Thank you!

 

[jerryjerry05]

817472 is the part#.
DO NOT remove the shift rod.
You might be able to pry the seal out??
The seal goes in metal side out.
The mating surfaces need to be spotless.
It needs sealer(I use OMC sealer) but not so much you coat the shift rod.
The rod make sure it's smooth/clean and gets greased.

If you can't get the seal out?
The cover can be removed and the shift rod removed.
DON'T unscrew the rod or you'll be working on the lower unit.
But it can be real tricky to get it sealed again.
Make sure you don't over tuorqe the nuts..

 

[Nordin]

Try drill a hole about 1/8 in with a drill bit in the metal then try to pry it out with a awl or use a metal screw in the hole and try to pry with nose pliers.

When the seal is out sand the fitting in the case for the seal.
Press the new seal in and use some Loctite fluid for bushings mounting to glue the new seal in place.

Check the shift rod so you can move it with not to much force.

 

[10dknezevic]

Thank you both for the help!!! I just got around to writing a reply. I was able to remove and put the new one in by drilling a small hole in the and putting a small screw in the hole and just prying it up. Seems to be just fine but the shift shaft is definitely harder to move up and down. Do you think this will be a problem? I tried lubricating and working it up and down but its still pretty firm.

 

[jerryjerry05]

Did you clean the old sealer/gunk out of the hole?
You clean the shaft?
Crud builds up on the parts and makes shifting harder.
Is it in flush? Not crooked?

Using your fingers to shift? You nor I am strong enough to really shift right.
You need to turn the prop shaft as you move the shift rod.

 

[10dknezevic]

Yes i cleaned everything. It was spotless. I am able to shift it with my fingers but it’s just very firm. I think it will be okay since it moves. Probably just because it’s new rubber

 

[Nordin]

If you can move and shift it with your fingers, then it is okey.
It is new rubber as you says and it will wear in after a while.

 

[jerryjerry05]

If you can shift with your fingers then it's ok.
The force the mechanical system delivers is about 100X stronger than your fingers.

Lube the shaft and top of the seal with a big O gob of grease