Shaft threads- Left Handed?

[PatrickF]

Hello, I know this should be an easy question but I haven't been able to find the answer. Are the threads for the prop bolts standard threads or is the starboard side reversed threaded? Thanks

 

[Bacchus]

Patrick
I cant speak for GB but AFAIK shafts are commonly RH thread and don't reverse the threads for twins. My logic says they need to operate in FWD or REV which is taken care of by proper installation of lock nuts (Thin first & thick last) and cotter pins / seizing.
Some (maybe not all) LH nuts are marked w notches on the points

 

[rslifkin]

My shafts are both RH thread even though they counter rotate.

On the thick/thin nuts thing, I've always understood the process to be to seat the prop with the thick nut, then remove it, install and torque the thin nut, then the thick nut after it. The idea being that the second nut somewhat unloads the first, so you want that one to have the extra thread area.

I'm not sure how much it really matters though, provided both are torqued adequately and lock together firmly.

 

[tiltrider1]

I have seen LH threads and I have seen both shafts RH. It’s a lot easier to find RH nuts should you loose one. I have always cotter pinned my shaft nut.

 

[Comodave]

Our last boat had one of each. The first time I took the props off it was interesting since I assumed that both would be RH.

 

[BruceK]

Even Alfa Romeo abandoned left thread wheel nuts in1972. Many a strained overtightened stud evidenced the need. Through (?some) bicycle pedals retain it.

 

[fgarriso]

My last 6 boats all had right hand threads.

 

[koliver]

One of each on my twins.

 

[artfulltune]

Well Pat, my 1988 Taiwan built Golden Star with twin Perkins Range 6's props spin port side, counter clockwise, i.e., "lefty loosey", starboard side spins clockwise, and the nut turns "righty loosey".