Yanmar 3GMF Transmission Oil Question

[Joe Mullee]

I'm using the same oil in the transmission that I use in the engine, Shell Rotella T 15W-40. The "full" notch on the transmission dipstick is very close to the very bottom of stick, just 1/4" from the end. When measuring the transmission oil level in this particular engine should I be measuring with the stick screwed all the way in or measure with the stick just resting on the top of the entry hole? The threads on the stick add about 7/16" to its overall length.

Thanks,
Joe Mullee

 

[Charles Erwin]

Do not screw it in. Measurement is taken with the dipstick sitting on the threads.
The oil level should be just at the lowest mark on the stick. As you know the distance from that mark to the end of the stick is very short.

Charles

 

[Benny17441]

The recommended oil grade for the kanzaki on the 3GM is 10w30. The shop manual recommends changing the transmission oil every 250 hours. The transmissions run cold when freewheeling under sail so the oil will be thicker especially in cold weather. We have taken to using synthetic oil in the transmission as it maintains its viscosity much longer stretching oil changes to 500 hours.

 

[Warren Milberg]

Joe: I read the Yanmar manual, p23, para 3.2.3. to mean you check the trans oil with the dipstick all the way in. The manual also recommends using SAE 10w30 oil in the trans.. See below.

 

[Charles Erwin]

Refer to this site for a summary of the transmission types and the quantity of oil specified for each of the KM 2 3 and 4 series transmissions.

http://www.yanmarhelp.com/i_box2.htm

You can verify the dipstick measurement is intended to be taken with the stick pushed in but not screwed down but doing the following:

Pump out all the transmission oil, measure fresh oil into a graduated container using the quantity specified by Yanmar (these are listed in the table in the site above), pour fresh oil into the transmission and measure the result with the dipstick. You will find that the oil level will be at the mark when you lower the dipstick to the threads - but not screwed in.

Charles

 

[Alan Gomes]

Joe: I read the Yanmar manual, p23, para 3.2.3. to mean you check the trans oil with the dipstick all the way in. The manual also recommends using SAE 10w30 oil in the trans.. See below.

But then, in the "Yanmar GM HM Workshop Manual," p. 61, it reads: "Check the transmission oil level on a weekly basis. With the boat at rest in the water and the engine off, unscrew the dipstick (Figure 39, typical). Wipe it with a clean rag or paper towel. Reinsert the dipstick, but do not screw it in. Pull out the dipstick and read the oil level on the dipstick."

FWIW, the dipstick shown in Fig. 39 looks a bit different from the one shown in the pages you sent (and is identical to the one in my Yanmar).

 

[Chris Patterson]

It's customary to check the level on a stick at the tops of the threads. The threads hold the stick in, that is all. I don't think I have ever seen a dip stick that you screw in to check the level, even lawn mowers.