Yanmar KM4A Oil Change

[duncan_ellison]

Hi all,

I have a 4JH3-TE Yanmar engine with a KM4A transmission attached. The boat had 300 hours on the engine when I got it and now has 1,000.

Although I've religiously changed the engine oil, I must confess that I've not paid too much attention to the transmission, so whilst I have a little downtime I intend to change the oil.

In the handbook, it talks about 'cleaning the oil filter' every xx hours, but I can't find anything which looks like the diagram they show on my particular transmission housing.

Does this relate only to certain transmissions Yanmar uses, or do they all have some kind of filter.

I can see what looks like a drain plug at the bottom of the housing, would that be a combined filter / drain ?

Duncan
Waiting to haul at Deltaville, VA

[Hudson Force]

I have the 4JH3E with the Kanzaki KM3P4. These differences my make my information irrelevant, but I have no transmission oil filter. I have pumped out my transmission oil from the dip stick access, but not as frequently as my engine oil changes. I currently have 5,323hrs on my Yanmar and I only change the transmission oil about every 800hrs. .....and I do use the 30wt motor oil, not ATF. 'love my Yanmar & Kanzaki! Take care and joy, Aythya crew

[jim_thomsen]

I have a 4JH4E with the KM4A1 and I do not think there is a oil filter and my manual - the big Yanmar Service manual does not say anything about changing a filter either. It does say to change the oil in the transmission every 250 hours, the same as the engine. I haven't kept up with that and usually change it every other engine oil change.
I should probably do it more often, since I have a pump mounted with a hose that can go into the engine dip stick or the transmassion making it easy.

[Tessellate]

I know this is an old thread but I had the same perplexing question about why the Yanmar manual says to clean the transmission oil filter.

Finally I noticed it has "KMH4A" written next to these instructions. Our transmission is the KM4A. I believe the H may indicate hydraulic transmission. On the Kanzaki website you can see pictures of these transmissions and note that they are very different.

So KM4A has no oil filter. However the maintenance schedule (section 5.1) recommendation to clean the *oil cooler* every 1000 hrs / 4 yrs still applies. However mine has never been cleaned in 6000 hrs / 20 yrs, and my diesel mechanic says he has never known anyone to do that. He said since it's a slow / low pressure raw water path it's not as critical to clean as the cooling passages of the heat exchanger and engine oil cooler.