Type and Amount of Fluids on R-21 3YM30 & Thuster Question

[TugNutinNorthTexas]

Hi All, hope your well. Question regarding my recently acquired 2008 Ranger Tugs R-21 EC with 30 hp Yanmar 3YM30 motor. Is anyone familiar with the type and approx amount of transmission oil & type and amount of coolant this diesel motor uses, wanting to change both? And noticing that the bow thruster makes significant amount more noise powering one way that the other... Does anyone had any suggestions as to what to look for and how to correct this noise problem? The boat is in a slip, so I will need to haul it, wanted to try to have the necessary parts on hand to repair the thruster. My guess is a bearing? Thank you...

 

[Capt’nKarl]

Good morning. I had a 2009 R-21EC with the Yanmar engine. Oil changes are easy. You can get Yanmar oil filters from Amazon. I believe the total oil volume needed with oil filter change is about 4 liters. Fuel filters and air filters are also available from Amazon. The transmission is a splash system and you need to use a good SAE30 weight, NONDETERGENT oil. The transmission case holds 300 ml. I found the best way to tackle the coolant in the radiator is to siphon as much out as you can and replace it with a compatible antifreeze. If you do this process several times you will effectively replace the old with the new antifreeze. As far as the bow thruster is concerned its not unusual for it to be somewhat louder in one direction. The spin and location of the prop make it turn better to Starboard than Port or vice versa. If it was a bearing I’d think you’d hear the noise regardless of direction. However if it is a bearing the whole motor can be removed fairly easily for better inspection. I pulled mine to have the brushes replaced. The Yanmar 3YM30 is a great engine that will give you many hours of enjoyment as long as she’s cared for properly. Don’t forget to fresh water flush the raw water coolant system occasionally. That will also keep the engine running well. Enjoy your boat! If you have any questions please let me know.
Cheers,
Capt’nKarl

 

[bob daily]

You might want to download the yanmar service manual for your engine, a great resource for future use. Also remember the coolant system is also the source for your cabin heater so you will never remove 100% of the coolant unless you drain the lines and heater in the cabin.
Good luck Bob