transmission help

[beuerle]

Hi. I'm hoping to get some help for our 2003 28 TE, engine box, with a Yanmar 6 LPA-STP and ZF HSW-630 tranmission. I'll preface this by saying that I am very new to (not very knowledgeable about) inboard diesel boats like our Albin, which we've been enjoying on the Chesapeake since buying her late last fall.

short story - Can the transmission on this boat be removed without pulling the engine out of the boat ? It looks like the the engine mounts on the forward end are attached to the transmission. Or is it possible to somehow support the engine so that you could take off the transmission without removing the engine?

long story- The problem is that when the transmission is in neutral, the boat moves forward very slowly. I've read about this as much as I could on this website, boat diesel.com , and elsewhere. It sounds like this could be caused by a variety of things, including serious ones like warped clutch plates. I had the boat looked at by the mechanic, who says the shift cables, linkages, and transmission oil are all okay. He also said that the prop is bent, which I can't really appreciate. He thinks the prop may have been bent by hitting something, and possibly this caused a transmission problem. He thinks it might be a selector fork problem. He would like to pull the prop and shaft to get them evaluated, and pull the transmission so that can be checked out by a transmission specialist. This would all be done while the boat is on the lift. I wanted to get some more info before I talk to him again.

The boat is otherwise running very well, except for some white smoke form the exhaust when running at cruising speed, which I'll leave for another time. It hits 3800 RPM at WOT, going 23 knots, and at 3300 RPM cruises at 18 knots, which is what it did during the sea trial. Engine temp and oil pressure seem normal.

He's also said the the boat should not be used until this problem is resolved.

I'd appreciate any advice or suggestions.

thanks, Brian

[RobS]

If all that you say has been checked and verified and it is slipping FWD (not REV) you can use the boat.

If you end up pulling the gear I'd pull it with the engine.

[GOING COASTAL]

Hi Brian,
I have not had one of these apart but I am a retired transmission specialist of 45 years in the auto industry both in dealership and manufacturing racing transmissions . I have looked at exploded views of your unit . First off it has no shift fork so that is out , there is a detent spring and ball in the
linkage housing that keeps the hydraulic shift valve in the correct position, if the spring is broken the valve could leak some pressure to the forward clutch holding the clutch on and the boat could creep forward , I would warm up the trans and put the boat in reverse and see if it operates as normal because if the forward clutches are warped due to overheating they will be dragging in reverse also and work to keep it from moving backwards as well. If reverse seems ok shut the engine off in reverse move the shifter to neutral and wait a minute , restart the engine and see if it creeps forward without moving the shifter. if it does not creep I would look at the detent if it does creep you will need to pull the trans and rebuild it and make sure your trans cooler isn't stopped up. If the prop and shaft are badly bent its possible that something in the trans was damaged as end play in the trans could have been thrown off and hydraulic pressure could be missed directed. Hope this helps some.
Good Luck Tom

[beuerle]

Rob and Tom,

Thank you very much for your replies, the information will be a big help as I work through this problem.
Brian

[Panhdjoe]

Sorry, i can"t be any help on how to pull the trans. I would like to point out that Running the boat with a even a slightly bent prop will cause uneven power pulses, vibrations and surging loads throughout the engine and drive train which will lead to big problems. I learned the hard way.

[RobS]

Ditto on the above. My comment about "using the boat" was referring only to the tranny, not the running gear that is in need of repair. Sorry if that was not clear.