J120TLLCA - Technical question about reverse issues and "ok" clutch dog.

[Jensdccom]

Heya,

I posted the bellow question on Reddit but they said that I would be helped better on these forums.

I have a Johnson 120hp V4 from 1988 (J120TLCCA). Engine works perfectly however the boat wouldn't go in reverse anymore.
Tried to put the engine in reverse manually (pushing it in reverse by hand) but the propeller would just spin freely (by hand).

Should be something in the gearcase.... so I wanted to check the clutch dog. Drained the gear oil and it was very milky. Seems that I do have a leak somewhere so I will reseal the complete thing.

I did notice that the engine could be pushed in reverse when the oil was drained/draining. Would it be fixed if I would just reseal and put new oil?

The clutch dog does seem to be "ok".

Found this rather strange and that's why I post my question here

 

[racerone]

Sounds like the shift rod height was not set correctly.---Was thrust bearing on reverse OK ?-----Best to reseal this gearcase.----Re-assemble.-----Pressure test the seals.-----Set shift rod height.----And test run.

 

[tphoyt]

Can’t say for sure but it looks like there may be some chipping on the gears.
If you still have the old gear oil run a magnet through and see what you find.
Maybe a chip was hanging you up from hitting reverse. It happens to my knees all the time.

 

[Jensdccom]

I'm not immediately in the possibility to clean it up a bit more and new pictures. I will take some extra pictures and will check again for metal chips. Haven't seen any and there were none on the magnetic gearbox/lower unit screw.

For the shift rod, does anyone know the correct length from the factory. Might as well just adjust, check, recheck but factory settings are always nice to know.

Lastly, last time they sold me this to seal of the gearbox/lower unit screws

https://www.allesmarine.nl/nl/johnson-evinrude-gasket-40-90-hp-31159

They told me to just put them on, no grease nor sealant. Was this correct as I suspect that these are the cause for the leak (will however reseal the lower unit completely, just to be sure)?

 

[racerone]

Your gears look fine to me.-----I could read that without needing a translation.-----Your location in Europe?------Make sure you change the seal on the shift rod.----Put grease between the back to back seals.