Changing seals

[Waterwhippin]

I'm having a lot of fun working on these old Johnsons. I'm to the point of doing my first lower untt/gearcase seal change. Is there a,special tool I can invest in that will make the job easier? I am working on a 5.5 now, but plan to work on mainly 5-25 hp Johnsons.

 

[jimmbo]

With exception of the 9.9/15, 5, 4, 3 1/2, 3, 2, and 1 1/2 hp the gear cases in the range you quote are all very similar in design/construction. There will be some differences regarding bearings. A press and bearing pullers would come in handy on occasion. Screwdrivers , hook tools, sockets, and wrenches will do most tasks. Almost forgot, some of the late model 20 and 25 have the thru hub exhaust gear case

 

[HighTrim]

If you are referring to 50s 60s vintage Johnsons, which I think you are, there are a few things which make things easier.

First is a tool to remove and replace the shift rod o ring. FR on this forum used to make a tool, but I don't think he carries it anymore, you can PM him. IF not, you can make a tool out of a length of 5/16" round stock, that you grind down to 1/4" at one end, over about 2 inches or so. This drives the bushing out, which holds the shift rod o ring in place, so you can replace it.

For the prop shaft seal, and drive shaft seal, you can then use a typical seal puller.

3M 847 is a product used to reseal them afterwards.

 

[Waterwhippin]

By typical you mean this one or the ones that look like bent screwdivers. Or the mini crowbar with a hook or the slide hammer?

 

[Waterwhippin]

Thanks for the tip on the shift rod bushing

 

[HighTrim]

Yes a puller like that works well for most drive shaft and prop shaft seals. Just careful what you leverage it on, that you don't break any castings.