Johnson PO-15 Lower Unit

[Buccaneer]

Decided today to take the lower unit off the PO-15 for
inspection. I removed the three nuts and was able to
get the gear case off, but not the piece above it,
that contains the lower drive shaft, bearings, etc.
Am I missing something?

In looking at info, it appears that it has a two piece drive shaft,
therefore I shouldn’t have to remove the pinion gear & nut
to get the housing off, correct?

I assumed it’s just gasket cement sticking it together. I’ve
tried heating the gasket seam with a little propane bottle
torch, tapping at the seam with a putty knife, and tiny
chisel. Also tried a brass punch and hammer on the one
remaining stud, as well as a block of wood and a hammer
on the nose of the housing.
I didn’t want to break anything, so thought I’d ask for advice!
Thanks!

---

Attachments:

Prepare to be boarded!

[Mumbles]

Your gasket probably has shellac or something holding it together so it should come apart. Don’t lose the little thrust washer on top of the pinion shaft when it separates!

Here’s a link to an article by Bill Salisbury about PO gearcases in the Jan. ’72 issue of the Outboarder Magazine. Search the library to as there is more info there on the PO’s.

https://www.aomci.org/members/outboarder … 72-40.html

[Buccaneer]

Mumbles, thanks for the link. I went thru all those archived articles a while
back, but forgot there was anything in them about the lower units.
My prop shaft is tight and turns smooth so things might not be too bad inside.
I can see tapering / wear on the pinion gear, but think it’s got
a few more miles left in it.
May have to get "more" heat on it to loosen the old shellac sealant!

Prepare to be boarded!

[jerry-ahrens]

Also, when you do get the lower unit off, be sure not to loose the short 2 inch water tube that connects the cooling line to the lower unit. They can fall out while carrying around the gear housing. Maybe try a small plastic coated dead blow mallet to knock the gear housing loose.

[Buccaneer]

I fired up the Oxy / Propane torch and heated up the seam.
Didn’t take long and the shellac gave up the fight.
Hmmmmm, will have to look for the 2" cooling line
to see if it’s even there!
Thanks for the warning!

Pulled one piston and rod out of the crankcase yesterday.
Had to heat the rod cap to get the two rod bolts to break loose.
Tried the same with the little bottle torch on the other side,
but they didn’t want to let loose. What’s up with that? Perhaps
someone used thread locker ? May have to try the big
guns on those as well.

Johnson 3rd addition manual mentions "rod cap bolt lock
washers (with tabs to bend over) on one page, then the
next page it says they not used on these models, just torqued
to proper specs……. I have none, and as tight as they
are, they were NEVER going to loosen by themselves, lol.

Prepare to be boarded!

[Author]

Posts