Tab washer for prop nut question...

[Captain Crisp]

Hi,
I've realised that the washer between my prop and nut (which I've had off recently) was intentionally bent around the nut to stop it unwinding.
However, aren't these sorts of fixing washers supposed to be attached to the prop with a small tab?
Mine didn't appear to be... In which case won't it simply unwind along with the nut? Or am I missing something?
You can see the - straightened - washer below. I'm there tomorrow, so can dismantle again...
Answers before next week's launch please!
Many thanks,
Crisp

 

[penberth3]

Hi,
I've realised that the washer between my prop and nut (which I've had off recently) was intentionally bent around the nut to stop it unwinding.
However, aren't these sorts of fixing washers supposed to be attached to the prop with a small tab?
Mine didn't appear to be... In which case won't it simply unwind along with the nut? Or am I missing something?
You can see the - straightened - washer below. I'm there tomorrow, so can dismantle again...
Answers before next week's launch please!
Many thanks,
Crisp

View attachment 115949

Is there a keyway? If not, was the washer hammered back over the prop hub and forward over the hex nut?

 

[reeac]

I've seen a locking washer with small tab that slots into the inner end of the shaft on a tractor PTO but never on a propellor. In my experience the washer needs to be very thoroughly flattened against the nut to be secure and probably shouldn't be reused.

 

[Poignard]

Tab Washer

 

[Captain Crisp]

View attachment 115950

Tab Washer

Yes... I didn't see any tab though, when I dismantled... Pretty sure I would've spotted that... perhaps I'm blinder than I think...

 

[Poignard]

Yes... I didn't see any tab though, when I dismantled... Pretty sure I would've spotted that... perhaps I'm blinder than I think...

Was there a keyway in the shaft into which a tab might fit? There are different types of key. My propshaft has a short keyway with a feather key so a tab washer would be no use and the castellated nut is secured with a split pin.

You could use a Nyloc nut. When T.Norris made me a new propshaft they supplied it with a nyloc nut. I didn't care for that as it would have meant me carrying a spare nyloc nut because I don't like to re-use them so I got them to cross-drill the shaft and supply a castellated nut. They didn't charge for the extra work.

 

[RichardS]

Is there a keyway? If not, was the washer hammered back over the prop hub and forward over the hex nut?

+1
Flattened both ways is the best you will do with a plain washer.

Richard

 

[Topcat47]

Tab washers are "soft iron" . They can be re-used as long as the tab is in place. I anneal mine with a gas blowtorch. Carbon steel is not going the stand that sort of treatment.

 

[Tranona]

The tab is bent over and fits in the keyway in the prop, nut put on, tightened, and then the washer bent over one or two flats on the nut. Wahers are cheap (in stainless) and reusable. Very secure.

 

[Neeves]

Volvo tab washers are stainless and the bend at the tab hardens and they fail - easily.

They cost peanuts buy a few at a time, then you will always have a spare - why on earth would you want to save money by re-using a. very cheap. tab washer.

I'm really not that comfortable with them - I use blue Loctite on the bolt and the nut. I prefer a drilled shaft and castellated nut.


Props appear to have a similar replacement schedule to anchors as at boat shows in Oz there are a similar number of prop makers extolling the advantage of their wares as anchor makers (in fact there are more prop makers than anchor makers). Taking out a stand at a boat show is not cheap - you need to have a decent turnover (and margin) to simply cover the costs. I can understand people upgrading but otherwise the only reason to replace a prop (or anchor) would surely be - they wear out - or are lost. I suspect more anchors and props are lost than is admitted - so be careful of re-using your tab washer (or cotter pin) - and use mousing wire + blue Loctite to secure your anchor shackle.

Jonathan

 

[oldgit]

View attachment 115950

Tab Washer

Have used both tab and nyloc nuts on my Mobo.
Drilled shaft and split pin is fine if you are merely removing and refitting existing shaft and prop, but even then its a faff lining up nut and shaft holes and getting nut tight.
Have seen shafts with three different holes
If lifted out , you have all the time in the world but if you are on drying blocks speed is of the essence.
If ever in the position of needing new shaft and or prop go the Nyloc or tabwasher route or both for the paranoid.
If need both new prop and shaft ensure its a commonly used taper. Saves grief and cash later.