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1973 Johnson 50: gearcase oil pump assembly

D

dh_user

New member
Hi all, here’s my engine…
  • 1973 Johnson 50hp, long shaft, electric start
  • Manual shift with hydraulic shift assist pump (as far as I can tell)

As I disassembled the gearcase, I was expecting to find some detent springs and balls, but there’s weren’t any in there. I don’t really trust what was in there when I disassembled everything, based on some other signs of bad service in the past.

Here’s my question: how many detent springs and balls should there be, and where should they be?
  • The marineengine.com diagrams show 1 detent spring and 3 detent balls (items 69 and 70 in the diagram below)… Not sure where they would go.
  • The Seloc manual has a diagram on page 7-86 for this model, and everything looks like it’sa match to what’s in my gearcase - other than the fact that there’s no spring or detent balls. If I’m supposed to have them, where would they go?

Here’s the me.com diagram.
https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1973&hp=50&model=50ESL73R&manufacturer=Johnson&section=Gearcase+Electric+Start

Attached is a photo of what parts were in there (mostly disassembled).
 
Shift linkage on side of motor is for the hydro-mechanical.----Why are you taking this gearcase apart?----Do you have the clutch dog off the propshaft ?
 
Hi, I don’t have to completely disassemble, but:

  • There was water mixed in the gear oil
  • The oil seals were trashed
  • The shift rod o-ring was completely missing from the housing, so I couldn’t use an air hose to test whether the bearing housing o-ring was good
… so I decided to remove the bearing housing.

There was sand everywhere in the gear case, and everything was just super dirty (I couldn’t tell the screen on the hydro pump was a screen until I washed it).

Thanks for confirming the hydro-mechanical shift type. I did remove the clutch dog after photographing its orientation.

Do I need the spring and balls? And should I remove the tension ring from the pump housing and completely disassemble and clean it? Right now I haven’t taken anything off it.
 
It would be prudent to assemble it the way it left the factory.----Did sand get INSIDE on the gears----Hurricane ?
 
Thanks racerone. I don’t even think I could hazard a guess as to how everything got as dirty as it was. Once I removed the bearing carrier, I didn’t see any more sand. But everything behind the carrier o ring was super dirty.

I guess my question is where do the spring and balls go? Should I trust the Seloc manual? Or is there something else that I’m missing?
 
No kidding! That was my favorite. For anyone out there with a similar issue, here’s what I got on another board; this info plus “just one more parts order” will solve it.
A665ACFE-7046-4596-9BBB-E4FCF13C8DD8.jpeg
 
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