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prop shaft length??

kbcave

Contributing Member
i have a 1985 aq125b w/270 outdrive. to order a new prop i need to know the shaft length..how would you measure the length of the shaft. mine has two sets of numbers, one is a part# a16142, the other the prop info i guess, 14r19mwc,, thanks kc
 
My guess would be that it is a short shaft but I would not buy a short hub prop until you get a second opinion from someone else here.
 
I just found some pics of the short shaft and a short shaft prop on my 270 that you can compare which might be of help:

DSC00011.jpg DSC00014.jpg

In the first pic, the bottom of the tape measure is against a spacer which does not appear in your pic. It was on the drive all along in it's almost 40 year life until last year when I installed a line cutter on the drive for the first time.
 
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If by "spacer" you mean this part, then yes.

16848.jpg
 
From what I understand, you can use a long hub prop on a standard shaft if you have an internally threaded shaft and you don't use the spacer pictured above. So, instead of using a tabbed washer that interlocks with the indents in the spacer, you use a long bolt threaded into the end of the prop shaft to secure the prop.
 
Assuming you were previously using the spacer between the cone and the prop, if you remove the spacer, you may be able to use a long hub prop. I'd ask a prop seller to measure the depth of a standard hub prop and a long hub prop and see how they compare to determine if the long hub prop with cone sans spacer will work or not.

volvo long hub  hardware.jpg volvo short hub  hardware(1).jpg
 
KB, let me add some clarity for you if I may.

In post #2 above, the schematics can confuse some owners in that they mention "Short Shaft" "Long Shaft"!

The 250, 270 and 275 all offer one exposed shaft length (when absent the spacer/line cutter).
The 280, 285, 290, SP and several others, all offer another exposed shaft length (when absent the spacer/line cutter).

Here is what's commonly misunderstood:
The 250, 270 and 275 all require the short spacer/line cutter.
The 280, 285, 290, SP and several others, all require the long spacer/line cutter.

Hre is the important part: Either nets the exact same exposed prop shaft spline dimension, but only when the correct and mandatory spacer is used.

With only one limitiation, this means that any hub prop (long or short) can be used on any of these lower units.
The exception is when we get into the long hub prop on an early lower unit that does not have the internally threaded prop shaft.
This has everything to do with the style of spinner (aka cone nut) keeper or locking system.

Since the long hub prop prevents the shaft from sitting "proud" of the hub, the SS tab washer can not be used.
This limits us to using the center keeper bolt.
The center keeper bolt works only with a threaded prop shaft (275, 280, 285, 290 etc).

IOW, without the internal threads (250, 270), the AFT-most portion of the 2 pc spinner cannot be used with a long hub propeller.
Well, it could, but we'd have no means of locking it!

If you indeed have a 1985 drive, it is more likely a 275 drive...... not a 270.
All 275 lower unit prop shafts offer the internal threads, and the exhaust outlet that is placed further AFT.
If you have a 275 (sounds like you do), this would mean that you have more propeller choice options.


NOTE: The spacer/line cutter must be used! No exceptions when using a propeller designed for these V/P drives!
The spacer/line cutter must be correct for the drive model, not the propeller!

NOTE: The sum of both halves of the 2 pc spinner, equals the 1 pc spinner dimensionally.
Difference being, that the AFT-most part (of the 2 pc spinner) reaches into the long hub propeller in order to fully thread onto the propeller shaft.
Without this, the long hub propeller cannot be used.

Point being... don't confuse yourself between prop shaft lengths!
As said, all of these net the same dimension of shaft splines when the correct and mandatory spacer is used.

Instead, concern yourself with the correct spacer/line cutter, the hub length and the type of spinner that can be used.
The 2 pc spinner gives you more options, but again, only if your prop shaft is internally threaded since the SS tab washer can't be used with the long hub.

Make sense? :)

.
 
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ricardo, as you can see mine says 270, it has the line cutter spacer and a spacer between the prop and the spinner.. it also is threaded for the bolt to lock the spinner. am i understanding the the long hub could be used with the right line cutter/spacer?001.jpg002.jpg003.jpg
 
ricardo, as you can see mine says 270, it has the line cutter spacer and a spacer between the prop and the spinner.. it also is threaded for the bolt to lock the spinner.

am i understanding the the long hub could be used with the right line cutter/spacer?

KB, yes, you are correct!

The shift cover on your drive may be from an entirely different drive since these all interchange within this style.
IOW, a 250 cover will fit a 280 and visa-versa, and so on.
So I'd not trust this alone!

The fact that your prop shaft is internally threaded, tells me that it is a 275... not a 270.... at least not the lower unit.
The 270 was not threaded this way!

Also, if your transmission has the oil fill plug @ 2:00 O'clock position over the shift mechicanism, it will likely be the 275.
If no oil fill plug, it is likely a 270.

I've not tried this, so I am taking an educated guess, but if a short spacer was used on a 280, for example, the prop (regardless of long/short hub) would contact the 280 ring anode.
So we have to understand that the prop shaft dictates the spacer/line cutter.... not the other way around.
Again, and excuse the redundancy:
250, 270, 275 all use the short spacer, and if you'll notice, the ring anode is also short.
280, 285, 290 all use the long spacer, and the ring anode is also longer.... much lilke the Duo Prop ring anode.

I think that the key in understanding this, is to realize that either of these prop shafts net the same length of splined shaft, but only when the correct spacer is used.

In your case, you are wide open to an array of props..... both long and short hub.
  • Short hub = full spinner (be it 1 pc or 2 pc) and the locking bolt and/or the SS tab washer .
  • Long hub = aft section ONlY of the 2 pc spinner and the locking bolt only.
Bottom line.... by golly I think you've got it! :D

Don't feel bad..... this has stumped many!
 
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Kevin, I see that you posted this on another forum, and I just read the thread and the thread linked to.
The one guy was not aware that the spacer was even attached (minus the line cutter) to his prop shaft.
Just make sure that you varify the information that you're getting.


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