Kanzaki KM3P4 problem Hunter 380

[MatCast]

Hi! I'm new here. Looking for some advice regarding my H380 2000 transmission. I've noticed two issues with it. First, when putting the boat into forward gear, we hear the transmission "slamming" into gear, making a loud noise. To the point where my neighbor at the marina though I've hit the bottom when I pull out of my slip. Secondly, I noticed the shifting arm (on the transmission) has to travel much further before the transmission gets into forward gear compared to reverse (see attached picture). I got it checked last year, the mechanic serviced it and said the cone is within the tolerances and he lapped the cones surfaces.. Maybe the center groove of the cone is worn?

Anyone had similar issues? not sure what to do. I'm looking for a pre-own transmission since this model is discontinued.
Engine is a 3JH3E (with 1800hrs)
Transmission: KM3P4 (original)

Any advice is welcome,

Mat

 

[Ralph Johnstone]

I take it the engine is about 800 RPM when you shift ?

 

[MatCast]

That is correct. The gear gets engaged and split of a second after the rpm revs up. Idle is 800 or so

 

[Ralph Johnstone]

Sorry, not too clear .................... are you saying that right after the gear engages at 800 RPM, something unknown revs up the engine ? Or have I got it all wrong ?

 

[MatCast]

When pushing the throttle at the pedestal the transmission cable engage the transmission and right after the throttle cable rev up the engine.

 

[Ralph Johnstone]

Do you still get the loud "slam" if you only place the transmission in gear but DO NOT increase the revs ?

As shown in your picture :

What is the rough RPM when the shifter reaches point #2. What interests me, is the engine at a great enough RPM to be causing the loud slam when it fully engages.

I can say that on my Kanzaki KM2P, if you advance the shift handle to point #1, it pulls the gear completely into forward and the revs stay at 800 RPM. From there, if you continue to move the shift handle, the RPM will increase. You do have a different transmission but I think the operation should be the same.

 

[MatCast]

Ill double check that. Thanks for your input!

 

[Ralph Johnstone]

Please let us know. This problem is worth losing sleep over.

 

[dlochner]

First, don't replace the transmission with another Kanzaki they suck, get a new ZF, it will run about $2K and then there are a few other parts that will be necessary to complete the job, it will be worth it in the long run.

If the internal parts of the transmission are good, the issue could be cable alignment. Make certain the shift lever is in neutral, you will feel a positive click when it enters. And then adjust the cable so it shifts smoothly and evenly back and forth. On the inside of the transmission the lever is attached to a cam, this allows the transmission to be either in gear or out.

What kind of transmission fluid are you using? These transmissions do not do well with Dextron IV or higher, the fluid is too slippery. It could be the cones are slipping and then slamming into gear. I was told by a transmission shop to use the ATF labeled for "older cars."

 

[Ralph Johnstone]

Specs for a Knazaki KM3P4 are rarer that chicken's teeth but the KM3P4 is listed as a torque limiter. I also found this for your Yanmar 3JH3E with no mention of a KM3P4.

No further info from my quick search. Some Kanzaki Xmissions may take SAE-CC oil or some may take ATF but the fluids are specific to each Xmission. Not to be swapped.

You might want to check what's in your Xmission at this time but DO NOT add anything until you find out what your KM3P4 actually requires.

Maybe if you live right, you have the wrong fluid in you Xmission and no permanent damage has been done. And maybe if you're really lucky, changing to the correct fluid will solve your problems.

 

[Tally Ho]

There should be a badge plate on the transmission… on mine, it faces aft…

it clearly shows fluid type (30 WT HD oil in mine).

Greg

 

[Terry Cox]

Kanzaki they suck

Always helpful to provide hard data/experience to support one's opinion about a product's quality/reliability. Our 1991 Kanzaki continues to perform wonderfully, as well as that brand did on our first boat.

 

[dlochner]

Always helpful to provide hard data/experience to support one's opinion about a product's quality/reliability. Our 1991 Kanzaki continues to perform wonderfully, as well as that brand did on our first boat.

First they are no longer made. Over the course of 8 short upstate NY seasons, the transmission fluid disappeared three time with no trace of where it went. The last time the transmission seized and was replaced with a ZF, which was easier to shift and cost a quarter of what a new Kanzaki cost when they were still available.

This was a KBM10 transmission which used ATF other Kanzaki's apparently use motor oil.

 

[Gary Ryan]

Just looking at changing out my gearbox oil and came across this thread. I believe my Kanzaki KM3P4 uses ATF, but I'll have to check the plate. Having said that, I'm having a brain fart. When checking fluid level, should the engine be running?

 

[dlochner]

Just looking at changing out my gearbox oil and came across this thread. I believe my Kanzaki KM3P4 uses ATF, but I'll have to check the plate. Having said that, I'm having a brain fart. When checking fluid level, should the engine be running?

No!! If the gears are moving they can come in contact with the dipstick. And now you have much bigger problems.

The dipstick on the Kanzaki and ZF transmissions that ATF can be difficult to read. Use a clean piece of paper towel, remove the dipstick from the transmission and lay it on the towel. The red ATF will show clearly on the paper towel. Check with the manual on whether to have the dipstick screwed down or not when checking the level, I can never remember.

 

[kloudie1]

Thhe deciding thing is whether the gearbox uses cone clutches or multi-plate clutches.. The cone clutch type Kanzaki (MP2, MP3) use motor oil and the multi-plate type (KBW.... ) use ATF. If the spec sheet is correct and it states "cone type servo clutches" then motor oil.. preferably a straight grade .. not multi grade.

 

[Gary Ryan]

Well, looks like the guy before me used ATF. The label on our gearbox says SAE20/30. I removed the old trans fluid and put in the proper oil. Onward and upward. Thanks for the help!