packing gland question

[sgbernd]

I am in the midst of re-powering my CD-28. The old Volvo MD7B had a left hand prop. The replacement Beta BD16 is right turning. Somebody said I needed to replace the packing gland because the left turning shaft tries to tighten the packing while the right turning shaft tries to loosen it. I checked the Spartan catalogue and found no reverse threaded packing glands are listed. So I conclude either CD only used left turning props (unlikely considering the multiple engine/transmission vendors used over the years) or that the whole idea is silly.

I place my money on the "silly" side, as the torque due friction from the shaft is so small (you can easily turn the shaft with your hand), but thought I'd see if there were any bad experiences with self-loosening packings due to friction on the shaft. Ever heard of such?

Steve Bernd

[Steve Laume]

Does this logic also dictate that you need a left handed prop nut? And good luck finding one of those.

I would go with silly, Steve.

[Astronomertoo]

Does this logic also dictate that you need a left handed prop nut? And good luck finding one of those.

I would go with silly, Steve.

Keep in mind many twin engine inboard power boats have one of each.
Bob C

[Neil Gordon]

Does this logic also dictate that you need a left handed prop nut?

That's why you always put in a cotter pin!!!

[tjr818]

Of course all of that is assuming that you are North of the equator

[Neil Gordon]

Of course all of that is assuming that you are North of the equator

South of the equator you just put the cotter pin in the other way.

[RC James]

Snug the locking nut up against the nut containing the packing, give it a good two-handed tightening motion, and you're good to go.

[John #126]

There is a difference between the direction of prop shaft rotation and a left- or right-handed prop. The pitch on the props is opposite with the shaft rotation remaining the same. If both engines' shafts rotate the same way, there is no issue, regardless of whether the prop is right or left handed.

[sgbernd]

Thanks for the inputs.

I thought so.

-sgb