| Author |
Message |
    
David Kain
Advanced Member
Username: hurrikain
Post Number: 141
Registered: 08-2008
| | Posted on Tuesday, September 22, 2009 - 06:03 pm: | 
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Anyone out there use a Long hub prop on a short hub drive? I have heard a few folks have but before purchasing a new prop would like to make sure it will work. The reason I want to is the pitch I want is no longer available in the short hub 14x23 unless someone knows of a manufacturer.
Thanks
Dave |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 611
Registered: 03-2009
| | Posted on Tuesday, September 22, 2009 - 06:14 pm: |
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Dave, there is no difference in the "prop shaft" length between drives...... and for either long/short hub propellers.
Each lower unit, with the correct "spacer/line cutter" lends itself to the same amount of usable shaft.
(250/270/275 must use the short spacer)
(280/285/290 must use the longer spacer)
The difference is in the type of spinner (cone nut) that we use.
**Long hub requires the AFT portion only of a two piece spinner...... (it actually reaches into the splines of the propeller some allowing it to fully thread onto the prop shaft spinner threads.)
**Short hub prop requires the use of either the one pc spinner, or both parts together of the two piece spinner.
. |
David Kain
Advanced Member
Username: hurrikain
Post Number: 142
Registered: 08-2008
| | Posted on Tuesday, September 22, 2009 - 07:12 pm: |
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I don't believe you are correct on that.. I have attached a image showing the different lengths and you can see the long version is approx 1 inch longer.
Dave |
David Kain
Advanced Member
Username: hurrikain
Post Number: 143
Registered: 08-2008
| | Posted on Tuesday, September 22, 2009 - 07:18 pm: |
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here is the image |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 612
Registered: 03-2009
| | Posted on Tuesday, September 22, 2009 - 07:38 pm: |
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David, forty plus years as a mechanic, and twenty plus years working on these drives says that I am. I've helped many people with this very same question..... and many times.
However, it is easy to see how this can be confusing.
NOTE before we go any further....
What the chart is calling a "thrust washer", is commonly known here in the US as a "spacer/line cutter".
What some call a cone nut, is actually a "spinner".
There is a one piecc spinner.... and a two piece spinner.
The chart above should really read;
Volvo Standard shaft = 200/250/270/275 shown w/o short spacer/line cutter.
Volvo Long shaft = 280/285/290 shown w/o long spacer/line cutter.
Net shaft spline area is same when the appropriate spacer/line cutter is used on either shaft!
**Look closely at both shafts. Yes, you will see that each grosses a different length. 280 being longer than a 270.
**Now look closely at both types of spacer/line cutters. (you will see a difference in length...... short on 250/270/275.... long on 280/285/290)
**Now consider the NET length of each shaft once the appropriate spacer is used on the shaft. (remember; short on 250/270/275.... long on 280/285/290)
**Now look at the recess within a long hub prop splines when installed on either shaft with the correct spacer/line cutter installed. You will see that the aft most part of the 2 pc spinner will protrude into this..... thus giving you the thread contact necessary.
**Now notice when a short hub propeller is installed, that the full spinner (or both pcs of the 2 pc spinner) works just fine.
**Also note that each type of prop-shaft bearing carrier... (AND ring anode).... are different. The result of this is a part of the mix regarding the required spacer/line cutter for each drive style.
Trust me.... It is not the shaft that determines which hub prop you can use.... not unless you have figured out a way to omit the spacer/line cutter.... and that cannot be done.
It is the hub style that determines which spinner style to use!
. |
David Kain
Advanced Member
Username: hurrikain
Post Number: 144
Registered: 08-2008
| | Posted on Tuesday, September 22, 2009 - 07:55 pm: |
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Ok I hear ya on that.. Yeah I can see where it would be confusing.. OK one more quick question then so using a long hub prop do you have to use the Allen screw to retain it all? The reason is my shaft doesn't have a threaded shaft, and I have always used the star washer. And BTW I appreciate the info on this.
Dave |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 613
Registered: 03-2009
| | Posted on Tuesday, September 22, 2009 - 08:05 pm: |
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Oh Dave.... you are very welcome. Sorry to sound so gruff on that last post, but this is a tough one to explain at times.
If your shaft is not threaded, it is a lower unit made prior to the 275 drive. Possibly the original T drive lower unit. |
Robert A. Fierro
Advanced Member
Username: sandkicker
Post Number: 905
Registered: 06-2008
| | Posted on Tuesday, September 22, 2009 - 08:07 pm: |
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I put a long hub on a 250 drive with the star washer. That "flavor" of long hub prop had slots in the prop to access the tabs to bend them.
I found that these slots weren't long enough to reach enough tabs. I took a round "swiss" file that was the same diameter as the slot and elongated the slot. I only had to elongate the slot about the diameter of the file plus a bit. I made very sure that I elongated each slot by exactly the same amount. You might not have to go thru that trouble however. |
David Kain
Advanced Member
Username: hurrikain
Post Number: 145
Registered: 08-2008
| | Posted on Tuesday, September 22, 2009 - 08:10 pm: |
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Yeah it is a 270T drive on a 74 Chrysler Conqueror S-III |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 614
Registered: 03-2009
| | Posted on Tuesday, September 22, 2009 - 08:42 pm: |
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Robert, I don't think he'll be able to use the locking tab washer with the deeper long hub prop.
The spinner portion of the 2 pc cone nut has no notches, nor will the splines of the tab washer have anything to anchor to since the shaft splines become recessed into the long hub.
Need a new plan!
If the spinner is the style with the tightening hole in it, I guess he could safety wire it to one of the washer lock tab holes in the hub.
David, after realizing that you have the older Chrysler set up, I'd suggest that you eventually replace the PDS bearings.
This may use the Holman Moody style PDS Adapter housing that we discussed here recently.
These use a much smaller aft most bearing.
She's a clean looking little boat! 
. |
joe_merchant
Member
Username: joe_merchant
Post Number: 33
Registered: 07-2009
| | Posted on Tuesday, September 22, 2009 - 10:30 pm: |
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Ricardo,
Thanks for the explanation - again. I went out on the Willamette last week and became a member of the "silver tipped prop club" so am looking for a rebuild plus a spare. Your explanation helps when looking for a prop for my old AQ280 drive! |
El Pescador
Senior Member
Username: el_pescador
Post Number: 4942
Registered: 02-2006
| | Posted on Tuesday, September 22, 2009 - 11:50 pm: |
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Hey Joe, what do you mean by "old AQ280 Drive"? That model has "only" been around since the mid 70s!!!!  I am currently running one on my boat, plus I have a spare for "just in case".  |
ken alsobrook
Member
Username: kalsobrook
Post Number: 9
Registered: 04-2009
| | Posted on Sunday, October 04, 2009 - 11:19 am: |
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El, so if I understood you correctly I can install a short hub prop on my AQ280 long hub w/2 pc. spinner as long as I buy the short hub spacer ring. My real question is do I also have to swap the long hub line cutter for the short hub line cutter since they are different in length? |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 647
Registered: 03-2009
| | Posted on Sunday, October 04, 2009 - 12:06 pm: |
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Quote: "..... so if I understood you correctly I can install a short hub prop on my AQ280 long hub w/2 pc. spinner as long as I buy the short hub spacer ring. My real question is do I also have to swap the long hub line cutter for the short hub line cutter since they are different in length?"
Ken, maybe re-read my previous info September 22, 2009 - 07:38 pm re; spacer/line cutter being specific to the drive model and propeller shaft.
We cannot substitute one for the other between the 250/270/275 (short spacer/line cutter) and the 280/285/290 (long spacer/line cutter) prop shafts!
**The spacer/line cutter is specific to the shaft length.
**Each shaft nets the same length when the correct spacer is installed.
**Long/short hub props will work on either shaft with the correct combination of the two part spinner.
It can be confusing until we realize the above.
Hope that helps! |
