Lower helm/flybridge gear change block

ianc1200

ianc1200

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Looking for help/advice. We've had issues with the block which takes the cables from the upper and lower helm positions to engage/change gears. Can you tell what this is called, and any guides about how to set them up?

This is the block

3 low.jpg


And this is the rest of the linkage onto the Hurth gearbox.


6 low.jpg
 
Is it a recent problem or one that has been getting worse, is it just the gearbox or throttle as well, do you problems at both helms or just one?
 
It is known as a D S UNIT ie dual station but not one I recognise it looks bespoke or even home made
The angle on the cable seems excessive which maybe a reason for problems
On reflection has this been posted previously?
 
Thanks for replies - it's been an evolving problem, but perfect when bought tail end of last year, I posted previously re the starter not working, replacing a solenoid, but it was an electrical switch on the Hurth gearbox which would not allow the feed from the starter to the solenoid unless in neutral. Adjusting the cable to allow for that (or some other reason) meant initially I couldn't get reverse, then forward, on the SB engine from either helm position. The angle in the cable/rod connection to the port engine is even worse, but seems to work OK, however the start of the problem was when during servicing the rod to cable connection broke during engine servicing, you have to crawl over the gearbox to get to SB side of the SB engine. I've taken video's of the operation of the cables/block/selector for the SB engine (and nothing seems obviously wrong) and will do so for the port side to compare. Engines are 250 BTA Cummins with Hurth 800A2 gearboxes in our Aquastar 38.
 
I would release the both ends of the cable and see if there is free movement, I wonder if it's not been lubricated for a while and gradually seizing up.

I agree with @scottie about the angle of the cable👍

Incidentally, we had the port gearbox cable shear whilst mooring on our berth, thankfully it sheared when in neutral. It took a few seconds to fathom when was going on ie throttle response but no thrust ahead or astern!
 
JOHNPEET said:
It’s one of these:-
DriveForce Dual Station Unit for Gearbox and Throttle

You wouldn’t think that it would make much difference, but it’s important that these units are well greased
Click to expand...

Many thanks John, I don't know how I would have found this out without your post. Fantastic we can ask questions like this - I didn't even know what it was called or a generic name - and get an answer so quickly.
 
ianc1200 said:
Many thanks John, I don't know how I would have found this out without your post. Fantastic we can ask questions like this - I didn't even know what it was called or a generic name - and get an answer so quickly.
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There’s an amazing range and depth of knowledge and experience on this forum, so almost certainly there will be someone who can assist with any query or situation that may arise.

This was an easy one for me as I have these units fitted on my PRM500 gearboxes.

Fit and adjust the cables with the helm controls and gearbox lever in the neutral position. Then adjust the position of the actuating rod on the gearbox lever to match the length of travel provided by the cable movement of the helm controls, to ensure you achieve the required position of the gearbox lever when in gear. Hope I’ve explained that ok 😃
 
JOHNPEET said:
There’s an amazing range and depth of knowledge and experience on this forum, so almost certainly there will be someone who can assist with any query or situation that may arise.

This was an easy one for me as I have these units fitted on my PRM500 gearboxes.

Fit and adjust the cables with the helm controls and gearbox lever in the neutral position. Then adjust the position of the actuating rod on the gearbox lever to match the length of travel provided by the cable movement of the helm controls, to ensure you achieve the required position of the gearbox lever when in gear. Hope I’ve explained that ok 😃
Click to expand...
John where do you keep your boat.
 
With plenty of grease and a 1/2" adjustment we seemed to have resolved the problem - gears now engaged from upper and lower helm positions. Fascinated to see, because comparing with the port engine, the lever on the port engine goes backwards/appeared to be in reverse, to drive the boat forward. I've had suggestions that the props might not be pitched the same to allow for the extra gear. What a learning curve!
 
ianc1200 said:
With plenty of grease and a 1/2" adjustment we seemed to have resolved the problem - gears now engaged from upper and lower helm positions. Fascinated to see, because comparing with the port engine, the lever on the port engine goes backwards/appeared to be in reverse, to drive the boat forward. I've had suggestions that the props might not be pitched the same to allow for the extra gear. What a learning curve!
Click to expand...
On my installation, i have handed props and one of my gear boxes runs in reverse (I think it’s the starboard one) to drive the boat forwards. This arrangement provides contra-rotating props.
Is this likely to be what you have?
 
I'm not sure, but beginning to think so. I need to look carefully at photo's I took when out the water, but also (re if differences in pitch) the previous owner left some information I need to check.
 
We have a similar cable installation on our Ocean 37 having an upper helm and lower one in the saloon, though with different gearboxes: Bog Warner "Velvet Drive" Hydraulic Transmission 72c with a 1.523:1 reduction.

The installation on my boat the starboard engine runs in reverse direction, the gearbox for that engine is also designed to run in the reverse direction, to give the handed propellor the correct drive.

Because the way the gearbox uses a engine driven hydraulic pump for the drive and lubrication there is a restriction on using the gearbox in reverse or indeed letting the gears be driven by the propellor, there is also a throttle stop when putting the gears in to astern to limit the amount of power going through the gearboxes.
The manual for the gearbox says no more than 1 hour of trailing as there will be no circulation of the oil and the oil, ATF, can overheat.
 
Ours has the gearbox on the SB engine running forward, and a RH 22 x 28 prop. The port engine gearbox runs in reverse to drive the boat forward, and a LH 22 x 28 prop (sizes and rotation noted by previous owner). Just checked revs at which gears engaged, SB idles at 700 and drops to 650 when fwd engaged, Port idles 780-790 and drops to 750 when fwd engaged. We thought the SB engine was revving higher, but also standing outside and listening no discernable difference between the two.
 
ianc1200 said:
Ours has the gearbox on the SB engine running forward, and a RH 22 x 28 prop. The port engine gearbox runs in reverse to drive the boat forward, and a LH 22 x 28 prop (sizes and rotation noted by previous owner). Just checked revs at which gears engaged, SB idles at 700 and drops to 650 when fwd engaged, Port idles 780-790 and drops to 750 when fwd engaged. We thought the SB engine was revving higher, but also standing outside and listening no discernable difference between the two.
Click to expand...
We have no discernible drop in rpm when engaging gear, rpm is around 500ish, I really have to watch what I am doing as it is hard to tell if you are in gear or out other than by the position of the lever, nearly had a whoops moment mistaking which was in and out of gear.
 
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