2022 Tohatsu 15hp Gear Oil Level

therosses5

Cadet
Joined
May 31, 2011
Messages
18
New outboard owner/Noob question. Replaced lower gear oil according to the manual after the 10 hour breaking. in. I had issues squeezing the bottle of oil just before it poured out the top so there was air coming out in spurts. I put the plugs in and tried the process all over to ensure it was topped off.

The Tohatsu manual states:
"To check your oil level, remove the top oil plug, insert a small piece of wire straight into the top hole approximately 1 inch and withdraw the wire. If oil is on the wire the oil level is correct, if not the unit must be refilled to the correct level."

The hole is on the side of the shaft. When I insert a wire straight in, there is no sign of oil. Wouldn't oil start pouring out of the hole if there was oil 1 inch straight in? If I bend the wire so it goes down an inch there is oil just above the tip. Is that enough?

Does "straight in" mean down the shaft or perpendicular to the ground?

Seems like all dumb questions but I'm nervous about not having enough oil in the lower unit.

I need to understand how to properly check the level and know if I really should be inserting the wire straight in or in and down one inch.

Thank you in advance.
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,733
Insert the wire down an inch. I use a very small white zip tie.
Basically you want the oil level to be close to the height of the vent plug.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
An Oil Pump it's a zillion times much better and efficient than filling new gear oil with the oil bottle, go for one. Simply remove both lower leg's oil plugs, screw fully in the OL nozzle at lower leg and pump a lot of oil till exists the upper drain hole, once there screw tight the upper plug, remove the nozzle and screw the lower plug tight. If both plug's gaskets are way dry, hardened, excessively crushed /deformed install 2 new ones...

Happy Boating
 

therosses5

Cadet
Joined
May 31, 2011
Messages
18
Thanks everyone. Much appreciated!!

My main question was about how to check the level based on the statement in the manual. That was answered.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
First time knowing such oil check level procedure existed, wasn't mentioned before on previous Tohatsu motors. If you fill compltely the gearbox with an oil pump or squeezing an oil bottle till oil pours out the upper hole no need to perform that procedure, provided the gearbox doesn't have an oil leak and you religiously change your gearbox oil at each 100 run hours intervals...

Happy Boating
 

therosses5

Cadet
Joined
May 31, 2011
Messages
18
It's more about reassurance if more oil leaks out than wanted while trying to put the bottom screw back in. I did buy a cheap pump so the process is much easier. Thank you!!
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
It's more about reassurance if more oil leaks out than wanted while trying to put the bottom screw back in. I did buy a cheap pump so the process is much easier. Thank you!!
To screw the lower bolt back on after fully filling the gearbox with new gear oil must adjust the upper bolt tight before removing the oil pump's noozle, that way will only lose some oil droplets which it's not that big deal when screwing the lower bolt back on. In any case don't overtighten too hard both bolts as will damage/deform both bolt's gaskets...

Happy Boating
 
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