Borg Warner 1:1


New member
9 Oct 2020
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Good morning boaty types,

I have an issue which I hope someone can resolve.

My Cygnus Cygnet has a 2725E Sabre built in line 6 linked to a sternpowr leg through a Borg Warner velvet drive 72C ( i think)

I have has a few issues with this box caused by ingress of sea water due to a burst heat exchanger.

A friend of mine had one for sale

Although it has a flange coupling output, and mine is a splined bore, I assumed that this would be interchangeable.

After a few hours of ferking about, I have determined that this is not the case.

The casting number on the "new" one is 10-05-065-903 as best as I can make out.

The number on my original is 10-05-065-901 as best as I can make out.

Do any of you know what the difference is?

#Borg Warner
#Velvet Drive


New member
27 Sep 2021
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Hi Keith. I am sorry that you have received no replies so far. I have a 71C with flanged output, and a parts diagram for it, but it does not show a splined output, so I cannot be of direct help to you. A few thoughts come to mind, however.

First, re-post your question on the Motor Boat Forum, where it is more likely to be read by somebody with the answer.

Second, contact Lancing Marine (Marine engine gearbox sterngear Ford Lehman PRM ZF ), because they used to sell Sternpowr with Velvet Drive gearboxes, and may be able to clarify matters, as well as sell you the missing bits.

Third, I suspect the numbers you have identified are model numbers for the different gearboxes. That raises the question as to whether the only difference between them is the output shaft and tail end casting. If so, it would be pretty easy to swap the relevant parts from one to the other, subject of course to cleaning up the old casting should it have suffered from the water ingress, and replacing bearings and gears within the assembly as necessary.