Yanmar/Kanzaki transmission no longer going into gear - please help

[Rdubs]

Hi everyone,
Recently bought a 2003 Jeanneau 37' sailboat, has a Yanmar 3GM30F motor with a Kanzaki KM2P transmission. Boat is in Miami. The boat needed a new shaft and the motor mounts replaced so I had the prior owner motor it to a yard up the Miami river. Work was done yesterday and I started to motor it out of the river and while waiting for one of the bridges to open with the transmission in neutral (we had been under way about 5 minutes), when I went to put it in gear the shaft did not turn. Neither forward nor reverse engaged anymore. I checked the oil and it was empty - shame on me for not checking it before, I thought the yard did but apparently not. I put about .25 liters of oil in it (capacity says 0.3L) and the shaft would occasionally rotate about half a rotation. I put a little more oil in but couldn't get it to rotate even a little anymore. The linkage to the throttle works, the level on the left side of the engine definitely moves when the gears are shifted. The shaft spins easily with a screwdriver so it isn't that the shaft is bound, the problem is definitely with the transmission.

Appreciate any thoughts. Also, if anyone knows a capable marine mechanic in Miami that would be a huge help too.

Take care everyone.

[Rdubs]

Sorry, quick followup. When I was checking the oil level, I must have over-tightened the dip stick because the threads on the plastic dip stick broke off and are now imbedded in the threads of the transmission casing. The dipstick plastic must have been really old, I didn't really twist super hard. Not really sure how to get those out.

[noelex 77]

Check that the throw of the linkage is within the specifications.

[Pete7]

Unusual for the plastic dip stick to snap like that. I wonder if the gearbox has been running for some time without any oil and has previously over heated, also weakening the dip stick.

You might get the rest of the dip stick out with a large stud extractor, but I think its time to pull the gearbox and have a look inside.

Pete

[gleason99]

Opps yes these dipsticks are noted for breaking off which is BAD. Mine was only about 5 years old and it snapped but I managed to retract the piece with a long pair of needle nose pliars. I would suggest a led light on a long gooseneck and maybe you can look down the hole since it is about 5/8" diameter. Good luck. My meachanic told me to just tighten the transmission dipstick with my thumb and little finger!

[AA3JY]

Place the transmission in reverse or forward..shaft should not turn..

New OEM transmission dip stick is about 70 bucks. There are after market versions available for less $$

[skipperpete]

Loss of drive could be caused by the mainshaft endfloat becoming too great if the bearings seized and spun in the alloy housing.....which is quite likely due to the lack of oil.
However it is unusual to lose both ahead and astern so it’s possible that the damper/drive plate has collapsed or stripped the splines. You can actually see your drive plate with a flashlight through the little ventilation window in your first photo. The dipstick bit of plastic should easily screw back out using a knife blade as a screwdriver but don’t force it and break the blade....

[Ladnerboy]

I have a kbw20 and a similar situation happened to me. New shaft etc. After travelling 25 miles to home dock the shaft slipped out of transmission.. Thankfully a nearby friend towed me . Lots of questions why and pointing fingers but pulled transmission and had it rebuilt. Point is there is an internal locking mechanism for shaft to transmission that wasn’t checked..
Is it possible that your shaft moved..

[Niall leslie]

As an ex. Yanmar dealer ( from many years ago! ) from your description it appears as though the clutch may to be re-lapped and adjusted ( if the clutch cone will allow this ) or the clutch cone replaced, lapped and adjusted etc. all as per specifications. First check that the gear linkage is fully engaging the clutch both forward and astern as per specifications. The oil level should be full, not 20%+- low and I recommend flushing it etc. even if the linkage proves to be the problem. Normally, to remove the broken off dipstick top, just use an appropriate screw extractor.
Best wishes,
Niall.

PS If the issue is clutch cone wear there is usually sufficient cone material for this procedure to be undertaken at least twice before replacement is required. A morning or an afternoon in the workshop is typically more than sufficient for a complete overhaul of the gearbox assembly if the parts are on hand.

[Tumbet26]

My dipstick broke off in exactly the same manner but no problems with my gearbox just a poor design and an extremely expensive replacement. I got my threaded plastic bit out using a narrow knife blade and unscrewed it carefully.

[glcalahan]

Following.

[Niall leslie]

Further to my earlier posting.
If you're technically knowledgeable and competent etc. then I suggest that you consider getting the workshop manual and undertaking the repair yourself. If not then i suggest that you stop messing around and get a Yanmar dealer to undertake the work for you. If there was a similar situation with your car what would you do?

Cheers,
Niall.

PS Even if it appears OK I suggest replacing the vibration damper plate at the same time and due to the lack of oil the bearings etc. may be OK or may be useless.

[geoleo]

The yanmar distributor in St Pete rebuilt my Transmission for $2000 10 years ago. New one was 3500.

[wsmurdoch]

I'd turn around and go back up the Miami River to Anchor Marine and let them fix the transmission. They are a Diamond Yanmar dealer and have been a great help to me in the past with problems while passing through Miami on our way to the Bahamas. Their Yanmar distributor is in St Pete. If you want to pull the transmission yourself, send it away, wait for it to come back, then reinstall it yourself; contact Rick Neary at East Coast Marine Transmission in South Amboy, NJ. He rebuilt my Kansaki KBW10 after it failed, after another shop had rebuilt it, after it first failed..... Rick's repair worked.

[Rdubs]

Hi everyone thank you for the very helpful input.
I wasn't able to disconnect and fully test the gear selector throw before I had to moor the boat. But there was also a pretty substantial oil leak, I think coming from the transmission, so I'm going to just get a good used one and have it replaced.

WSMurchoch - Anchor Marine is who I'm going to have do it. The guy who runs that shop, Mike, is awesome. The water pump seized when I went to originally test it and he had a replacement in stock and gave a lot of pointers. He said have the replacement transmission shipped to him directly and he would bench test it for function and leaks, and then his guys can install it pierside. Also going to get his shop to do the routine maintenance on the 3GM itself. I'll see if I can get him to tell me what's wrong with the old transmission once it comes off, if so will post that info here. Fingers crossed, will see what happens.

Thanks again everyone, stand by for either glory or defeat.