Gear oil level on dip stick, 3GM30

[fredrussell]

Hi all. The dipstick on my new-to-me boat’s Yanmar gearbox is about 40mm long with a line about 5mm from the bottom, but no other markings. Does anyone know if that’s the max or min line? Oil level at present is a tad below the line so I’m hoping it’s the max line.

 

[VicS]

Hi all. The dipstick on my new-to-me boat’s Yanmar gearbox is about 40mm long with a line about 5mm from the bottom, but no other markings. Does anyone know if that’s the max or min line? Oil level at present is a tad below the line so I’m hoping it’s the max line.

Its the maximum .
The dipstick should not be screwed in when measuring the level

 

[coopec]

Its the maximum .
The dipstick should not be screwed in when measuring the level

Is that a general rule? e.g. for my lawnmower?

 

[vyv_cox]

Is that a general rule? e.g. for my lawnmower?

Not in my experience, although not many gearboxes have dipsticks. This one is something of a Yanmar 1-2-3 speciality, possibly not even applicable to all their engines, don't know for sure.

 

[pvb]

Not in my experience, although not many gearboxes have dipsticks. This one is something of a Yanmar 1-2-3 speciality, possibly not even applicable to all their engines, don't know for sure.

The screw-in dipstick on Volvo Penta 130 saildrives shouldn't be screwed in when reading oil level, either.

 

[pvb]

Is that a general rule? e.g. for my lawnmower?

Depends on the make of engine. The Kawasaki engines in my ride-ons have dipsticks which shouldn't be screwed in when checking the oil level.

 

[tudorsailor]

Hi all. The dipstick on my new-to-me boat’s Yanmar gearbox is about 40mm long with a line about 5mm from the bottom, but no other markings. Does anyone know if that’s the max or min line? Oil level at present is a tad below the line so I’m hoping it’s the max line.

You should be aware that the cap of the dipstick can break off the shaft on Yanmars. It has happened to mine twice at about 4 year intervals. It seems to be a problem with the plastic. So worth buying a spare and also looking at threads that advise how to get the shaft out.


TS

 

[vyv_cox]

You should be aware that the cap of the dipstick can break off the shaft on Yanmars. It has happened to mine twice at about 4 year intervals. It seems to be a problem with the plastic. So worth buying a spare and also looking at threadsthat advise how to get the shaft out.

View attachment 93637
TS

Yes, this has happened to me twice. Having paid a small fortune for a replacement, when it broke I managed to join the two parts together with a couple of self-tappers. The stickiness of the plastic suggests that Yanmar have managed to select one that is not resistant to warm oil.

 

[fredrussell]

Thanks all, much appreciated.

 

[tjbrace]

When mine broke a local engineer welded the ‘stick’ to a cut up spark plug that had a compatible thread. Hasn’t broken since.

 

[JimC]

Balking at paying the £47 replacement cost, when mine broke I bought a stainless steel hex pipe plug like this, drilled an 8 mm hole through it (the hex socket centres and guides the drill) and epoxied the tube into it. In the unlikely event of the epoxy failing the belled upper end of the tube will hold it in situ as it did in the original plastic fitting. I epoxied on a bit of scrap aluminium for a finger grip and drilled through to connect with the tube, which acts as a breather as well as a dipstick. All done for under a fiver and a better job to boot!

 

[Babylon]

FWIW the TMC40 gearbox on my Beta 25 has a dipstick which has max/min marks cut into it and which just plugs in - the oil level reading is taken from the plugged in position.

I don't see why a gearbox dipstick needs to be threaded in - its not a pressurised system.