Hurth transmission - ID & service

[Trekka]

Continuing to dig deeping into the engine room, I am about to start checking out the transmission, cleaning, changing fluid, and anything else that I can do while the heat exchanger is off and out of my way. This is connected to a Perkins 4-108.

First I need to ID the box. Here are twopictures which show the ID plate, which unfortunately still leave detail cloudy.





They appear to me to show:

HBW 10 - 2R

947 - 48 or 947 - 40

Ser 04-18010

Anyone recognize this?

[never monday]

is't a Hurth 10, later known as a 100 then a ZF10

[delmarrey]

Originally Posted by never monday

is't a Hurth 10, later known as a 100 then a ZF10

Yep! That's it.

[Trekka]

Thanks!

Looking at the transmission sticky in this forum, it lists models and capacities.
Is this the right line for mine:

Model Capacity in Quarts
HBW 125 (12M), HBW 150 (15M) (nee 10) .63

[never monday]

not exactly, but the quantity is close. The 10 should be about 1.5 ~ 2.0pts.
Unscrew the dip stick it'll have one line around it. This is the high mark when set on the threads and not screwed in.

[Chief Engineer]

Trekka, you are one hard working guy/gal (Ya never know). Whereabout on the Chesterpeake are you?

[Trekka]

Thanks,

I meant to be sailing, not disassembling my Perkins. But once started... and it's a good thing... because this beast really needed its plumbing cleaned out. If the water pump bearing had not frozen I would still be poking at the problems instead of really dealing with them. And I'm getting a close look at the issues that will need attention next year. At some point... I should replace the engine mounts. That will make all this seem like a cakewalk.

Currently in southern Maryland, but may move for the winter up to the West River, Magothy, or Baltimore. I'm checking the possibilities out tomorrow. Don't need much facilities-wise. Just a large enough slip, deep enough water, place to plug in a cord now and then, less of a drive to get there... and not paying more than I am now. Not asking much...

Steve

[Trekka]

Ok, I'm putting things back together on my 4-108, but before I put the HE back on I want to change the transmission's fluid. I used an oil extraction pump to suck the ATF out of the Hurth. I then poured about 3/4 of a quart of new fluid in and checked the dipstick. And there's the problem: the new ATF is so clean that I cannot see on the dipstick just where the fill goes to. I've tried dipping the stick in a small cup of ATF to see what it looks like on it, and cannot see the line. It's just too smooth and the stick too shiny. Any suggestions? I'm thinking of taking a wood stir from a coffeshop and trying that.

[CSY Man]

It's just too smooth and the stick too shiny. Any suggestions? I'm thinking of taking a wood stir from a coffeshop and trying that.

You will see the fluid level using a flash light or some other light source at the right angle. The level may be just at the mark on the stick and hard to see.

The Hurth tranny is pretty much bullet proof and has been maintenance free for 10 years on my ship.

This one is rated for 75 HP and should last a long time on the CSY 33.

I checked the price on a rebuild a few years ago and then it was $800.00.

Change the fluid every 300 hours and you should be fine.

[Trekka]

Is there a danger if the level is too high? Say a half inch over where it should be? Just wondering. I'm going to try a wooden stick and see if I can see the fluid on that.

I've owned this boat since '05 and this is the first time I've changed the ATF in the tranny. Don't know when the PO did.

[Pete the Cat]

Yes. There is a problem if the fluid is too high. It will blow out the gaskets. Don't ask how I know about this.

[Jim Cate]

My Nanni 43hp motor had a Hurth 100 when I bought the boat. Painfully soon after purchase the clutches in the tranny failed. Disassembly revealed not only badly worn clutches, but spalling on several gear faces. Cheaper to replace than to rebuild, so did so. Vendor failed to tell me that there was a ZF12 now available which was a drop-in replacement, and only marginaly dearer (guess he didn't have one in stock). Anyhow, my manual says that the ZF10 uses
only 350 mL of fluid, and warns to not overfill. I too have a hard time reading the level on the dipdtick,so tend to carefully measure the volume of oil into a separate container before funneling it into the case.

I also did some internet research, and found a gripe site for Hurth owners (don't remember where), and the consensus was that you should use Dextron III grade ATF, and change it frequently. So now I do it each time I change the engine oil (200 hours), and have had no trouble in the ensuing 1700 hours of use.

Good luck with it.

Jim and Ann s/v Insatiable II lying Gladstone Qld Oz

[skipperaris]

Originally Posted by Trekka

And there's the problem: the new ATF is so clean that I cannot see on the dipstick just where the fill goes to. I've tried dipping the stick in a small cup of ATF to see what it looks like on it, and cannot see the line. It's just too smooth and the stick too shiny. Any suggestions? I'm thinking of taking a wood stir from a coffeshop and trying that.

You are right. I cannot see it either, although I used to able to and my son - 30 years younger - is puzzled with my infirmity...
The way I do it now is to have a piece of paper tissue (toilet paper) handy.
When I unscrew the stick I dry it thoroughly.
Then lower the stick up against its thread - no screwing.
When I lift the dipstick I put it on the tissue.
No wiping action, just contact.
This shows the level clearly.
Try it!

[glymroff]

I know this is an old thread. But I have the same trans ( I think ) :
HBW 10-2R
947.40
No 4 17862

I need a rebuild kit or a drop in replacement. I'd also like to know what the actual gear ratio is. A surveryor thought it was 2.47 to 1.

Thanks

[MerryBee]

Hey Glymroff! you've just entered...'The Twilight Zone'! Check out my thread: 'Hurst Rebuild' - yes, I spelled it wrong - for lots of info on this. My HBW-5 is sitting on the bench in pieces right now waiting for reassembly. Exact replacement unit may be impossible to find, parts are scarce (some key parts maybe not available at all). Some have suggested Paragon transmission as an upgrade... Either way, be prepared to spend some boat bucks on this. You mig.ht reach out to Jim at Federal Marine Transmissions Marine Transmissions, Velvet Drive, Paragon, marine transmission parts, <marine transmissions>; a very knowledgeable guy.