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post #11 of 18 Old 08-22-2009
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Bill, you can pick up a "mechanic's stethescope" for $5-25 in auto parts stores. Or a nurses' grade one for the same price in a pharmacy.

The mechanic's scope has a stiff metal tube instead of a bell at the business end (6" of thin metal tubing will do, from a percolator or plumbing supply) and when you move that tubing around, it will localize the source of the noise.

Great for places where there may be hot moving parts that you don't want to stick your EAR into.
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post #12 of 18 Old 09-03-2009 Thread Starter
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The problem just got worse...

Here are the symptoms: anyone got any good ideas?

The history of the problem is as follows:

3 or 4 weeks ago, we noticed an unusual noise in the transmission – intermittent and I could chase it away by changing the engine revs. I isolated it to the transmission – since the noise only occurred while the boat was in gear.

I discovered that the shaft end zinc had gone walkabout and that the propeller was loose on the shaft. That was tightened 2 or 3 weeks ago and the zinc replaced – no change in the noise occurrence.

The stuffing box was letting in far too much water – so last week I adjusted it (first time). It no longer leaks, and the stuffing box runs cool.

Last night, motoring to the mooring, I was unable to get any speed, so went below and found that I could easily stop the prop by putting my foot on the rotating shaft. At this stage I was thinking clutch? (I guess these gearboxes don't have clutches though?)

I managed to get the boat to the mooring (slowly) and when there, found that I still had full power in reverse.

I noticed that lever on the gearbox that changes gear, was in the full forward position – such that if it wasn’t quite properly engaged, the cable could push no further to engage it. I therefore loosened the lever and re-positioned it – so that it effectively would have a longer throw forward – but clearly buggered something up because I now have no forward or reverse capability. It got dark - so I came home!

The gearbox is a 2003 Hurth.

I remain hopeful that this is a relatively simple cable/actuating problem rather than a major transmission failure – but don’t know enough about the system.

Any thoughts?

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post #13 of 18 Old 09-03-2009
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Originally Posted by billbalme View Post
The problem just got worse...
Any thoughts?
1. disconnect the cable, manually shift it at the gear box,
this should tell you if its a cable problem. Use a hex wrench
or screwdriver put through the hole to give your leverage if
you need it.
2. if all ok, shift into fwd at the gear box, and throw shifter
into fwd, attach cable, throw into reverse, check all ok,
make sure cable is properly attach at the shifter as well.
3. if not ok, then I think its time to rebuild gear box.


PS31#111 Cielo Azul
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post #14 of 18 Old 09-04-2009 Thread Starter
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The gearbox is cooked. Rats!

Anybody taken a gearbox out of a 37? Difficult job? does the engine have to be dismounted or is there enough room for it to be removed by unbolting the bell housing?

I'm thinking I'll replace with a new box - any recommendations as to where to get one? It's a Hurth HBW 100.

Is this something I can do myself or do I need a mechanic?

Where do I get a damper plate from (I understand that it's standard practice to replace this once the gearbox is out of the way...

Rats again!
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post #15 of 18 Old 09-04-2009
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Hi Bill,
I had to do the exactly same job several years back. I believe we have the same engine/gearbox (Universal 5432 & Hurth HBW 100). I replaced ours with a new gearbox and put in a new damper plate at the same time. The job is not difficult but does require some planning due to the short-coupling of the 37's engine and prop shaft, requiring lifting the back of the engine to clear the shaft flange and remove the gearbox. As best I remember, the steps went something like this:

1) Disconnect prop shaft flange from gearbox, slide shaft aft slightly. Disconnect exhaust hose from waterlift. Remove top nuts from aft motor mounts, loosen top nuts on forward motor mounts.
2) Lift aft end of engine enough to clear prop shaft when removing gearbox- as I remember this was about 5". (*see below)
3) Remove bell housing bolts and pull bell housing/gearbox combination off engine. You will have to slide it aft about 2" to get the gearbox spline out of the vibration damper on the engine. The 4 bolts that secure the gearbox to the bell housing are inside the bell housing.
4) Once the bell housing is off, you can swap the new gearbox for the old.
5) Before replacing the bell housing and gearbox, replace the vibration damper. It is bolted to the aft face of the engine flywheel. It was good that I planned to replace ours, as it had several broken springs.
6) Replace bell housing/gearbox- you may have to wiggle it a bit to get the gearbox spline started into the spline on the vibration damper. Once seated replace bolts.
7) Lower engine onto aft mounts, slide prop shaft forward to gearbox flange, and reconnect exhaust hose to waterlift. Realign engine, good alignment is very important to get max life out of your new gearbox.
8) Reconnect gearbox linkage being sure that when actuated by shift lever that the lever on the gearbox has the proper throw. The Hurth manual supplied with the new gearbox describes this.
9) Add oil to gearbox, go sailing. Recheck engine alignment after several hours of use.

* To lift the aft end of my engine I used a turnbuckle attached to the aft lift eye on the engine. I secured the top end of the turnbuckle with some chain to a hook. The hook was placed in the opening in the cockpit front made by temporarily removing the instrument panel. A jack under the engine may be another way of doing this.

Hopefully I did not make this sound tougher than it is. As I remember it took me about 4 hours.

Dave Dias
Crealock 37 #151
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post #16 of 18 Old 09-05-2009 Thread Starter
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After yesterday's post, I found Foley Engines in Worcester MA - "Dr Diesel" was extremely helpful and indicated that even I could do this... so I bought a new gearbox - $1,300...

On the way to the boat, I got Dave's fantastic step by step description - which I followed...

Last night I stopped due to poor light - but this morning all I have to do is alignment - looks very good up to now - fill engine with water and head off to Martha's Vineyard to enjoy the three day weekend afterall!

Fingers crossed I did it all properly!

Thanks to all - great instructions Dave....

Bill (forwards and backwards again) Balme
s/v Toodle-oo!

PS: I did get a chuckle - and a possible explanation...
Someone at some point had told me that when sailing one should put the drive into forward gear... The new gearbox had a red label on the gear selector which read read "NEVER put the gearbox into forward while sailing - you WILL damage the transmission. Leave it in Neutral or reverse."
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post #17 of 18 Old 09-07-2009 Thread Starter
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Back from a great weekend - with unfortunately lots of motoring - and the gearbox works waaaay better than the old one which we had to fight into and out of gear... You just don't know what's bad until you get it fixed or replaced...

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post #18 of 18 Old 09-30-2009
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tranny noises

I would agree with all the imput. Great threads!
You do want to give a best effort to locate the noise before you haul the boat. You will not be able to repeat the problem for any mechanic.
While you are checking the Prop, have the person in the water check for play in the shaft at the cutless bearing. More than 1/8" is cause for noise and the need to replace. We have also heard that type of noise when the trans. bolts were loose at the trans/shaft flanges.
To stay further back while checking for the noise, you could also try a long four foot wooden dowel, with your ear to the wood. And, yes watch out for those turning parts. no neckties,
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