87 Johnson 90HP Lower Unit Clicks

[kencat]

Replacing the impeller and I noticed that when the drive shaft is rotated in neutral (and forward and reverse) you can feel a detenting action with an attendent low sounding click. Is this normal? There are about 13/14 detents in one shaft revolution. Everything is very free and easy, and the shift shaft moves freely and engages well, but I'm thinking the drive shaft should rotate smoothly and silently.

Drained the gearcase oil and the first fluid to come out was water, the rest of the oil was milky so I know there is water getting in somewhere. There was not shavings/chunks in the oil though. I did notice the milky fluid coming out around the top driveshaft seal under the impeller as I was rotating the shaft.

IS this thing toast?

 

[DJ]

Re: 87 Johnson 90HP Lower Unit Clicks

I think you're just hearing the gears meshing.

The most common place for a L/U leak is the fill and drain plug seals.

 

[kencat]

Re: 87 Johnson 90HP Lower Unit Clicks

I think you're just hearing the gears meshing.

I was hoping so. I guess with the impeller in place it dampens out this audible detent feeling. I also had the gearcase on the old picnic table with the skeg down into a space between the planks (works well), and maybe this amplified the sound.

The most common place for a L/U leak is the fill and drain plug seals.

I'll get new ones before refilling. What about seing the fluid coming out the top seal? Because of the water mixed in? The seal itself looked in good shape.

 

[DJ]

Re: 87 Johnson 90HP Lower Unit Clicks

I was hoping so. I guess with the impeller in place it dampens out this audible detent feeling. I also had the gearcase on the old picnic table with the skeg down into a space between the planks (works well), and maybe this amplified the sound.



I'll get new ones before refilling. What about seing the fluid coming out the top seal? Because of the water mixed in? The seal itself looked in good shape.

The picnic table thing is a GREAT idea!

You may have an issue with the top seal. Run the engine and recheck your L/U oil.

 

[kencat]

Re: 87 Johnson 90HP Lower Unit Clicks

Thanks DJ.

 

[emdsapmgr]

Re: 87 Johnson 90HP Lower Unit Clicks

In addition to the drive shaft seal on the top of the lower unit, check the shift rod oring. It can also leak when they get old. A factory seal kit will include one.