[Michael Jungvid]

Turns out I need a bit more help. I was confirming the gearbox type with the broker who checked with the builder and says this particular boat has a Cummins gearbox. I have googled this but don’t find that Cummins do marine gearboxes. He also sent me this for details on the gearbox:

Code article…: 123381 GR CUM QSC8_3-495+2 1 BD DTS

N° moteur 1……….: BD:73087940

N° inverseur 1…….: 20108786

N° hélice 1……….: 660X850LH50

As far as I can tell it does not state what gearbox is in the boat, would you agree?
Also do Cummins do their own marine gearboxes?

The last line would be the props btw.

[Michael Jungvid]

I did not question the info on the D9 reference and was looking for a quick answer to decide if I should walk away from the boat before getting into the “marine age” stuff but now realize it was indeed not the right question so sorry for that and thanks helping me figure it out.
As you say without knowing more about the boat and how it’s propped there is no way to answer my original question properly. I will move on from this trusting that the drive line is appropriate for the boat.
Again thanks for your patience and help.

[Michael Jungvid]

Thanks Philip for answering my actual question and I understand what you are saying but it is not the help I needed. This will my 14th boat and I have undertaken similar trips in a lot less capable boats multiple times before. I know very well what you all are trying to help me with but It’s not actually helping.
I agree 100% this is not something I should worry about and frankly I did not until another mechanic pointed me to the spec sheets with specific example of this gearbox failing paired with the Volvo Penta D9 500 engine which has a bit less max torque.
Being thorough I wanted to seek confirmation one way or the other. This forum and Tony came highly recommended wrt to the drive line specific to the boat so I reached out.

[Michael Jungvid]

I am well aware of all the potential issues buying a used boat and perfectly capable of managing this but that is not what I was asking or hoping to get help with.

Assuming the drive line is properly maintained with less than 200 hours light use will I wear or break the gearbox prematurely running 100 nm per day @ 20 knots for 25 days?

[Michael Jungvid]

You are right it don’t come out right and I assure you I “have a clue” but agreed I skipped a few details on the travel plan but either way it was not the point and not what I wanted to discuss.

The boat should well be able to do 100-200 nautical miles per day and sea state permitting on the plane.

[Michael Jungvid]

Thanks Tony, I figured it was odd for a large manufacturer to fit the “wrong” gearbox.

I read the different usage scenarios and if I buy the boat the delivery trip will potentially be approx. 100 nm per day for 25 days at around 20knots (hopefully). Would this be over stressing the gearbox? If so is there anything I should/could do like change the oil every 50 hours or so?

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