Replacing lower units and stainless props

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,420
You hear guys all the time saying things like ?if you hit something with aluminum 90% of the time all you will have to replace is the prop!!!! hit it with stainless and most of the time you will be fixing your entire lower end or outdrive.?

How many guys running stainless props have needed to replace or rebuild a lower unit when you hit something?
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Replacing lower units and stainless props

I run stainless, use a depth finder all the time, run slow and easy around stumps, rocks, shallow water, but have no doubt in my mind that the odds of tearing up a lower unit with a prop strike are much higher with stainless than with aluminum or composite. If I ran in real shallow, rocky or stumpy water a lot I'd be tempted to invest in a composite or aluminum prop. So far, so good!
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,184
Re: Replacing lower units and stainless props

How many guys running stainless props have needed to replace or rebuild a lower unit when you hit something?
Ayuh,... You can count me as #1...
 

emilsr

Senior Chief Petty Officer
Joined
Dec 16, 2010
Messages
774
Re: Replacing lower units and stainless props

If you're concerned about hitting something in the water and tearing up a lower unit, use a delrin hub (like Mercury's FloTorqII). This way the hub will take the shock rather than the lower unit itself. A new hub is a heckofalot cheaper than lower unit parts (or a new prop).

After I made the switch to stainless from aluminum many years ago (on an 85hp outboard) I'll never go back.
 

R Socey

Chief Petty Officer
Joined
Jan 9, 2011
Messages
501
Re: Replacing lower units and stainless props

When I purchased my boat it came with two dinged up ss props, and two bent skegs, and I think one lower unit rattle!
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Replacing lower units and stainless props

I run nothing but stainless props. I have bent a couple and broken a couple of skegs from borrom hits. The only lower unit internal damage I have EVER done was on the straightaway in deep water when I snapped a prop shaft at full throttle.

Stainless steel props with rubber hubs DO use a higher durometer rubber hub so, it will take more force to spin the hub. Whether the extra force is enough to actually damage the lower unit internals is a question I can not answer.
 

Brewman61

Ensign
Joined
Jun 10, 2010
Messages
996
Re: Replacing lower units and stainless props

To me it's a matter of offset. Aluminum props get damaged way easier than SS. So a hit that dings a AL prop might not even harm a SS. Stainless costs more and is more expensive to repair, but should theoretically require less repair and last longer. I like the performance of my SS prop way more then my AL. I suppose it's possible that a bad hit on a hard prop might be liklier to transmit damage to the gears, hopefully the hub would spin out first. I'm stickin with my SS. Use the AL as a spare.

To further complicate things, we only know what did happen when we cracked the prop. We don't know what would have happened had the prop been AL instead of SS, or vice versa. Without some very controlled and expensive testing, you'd really never know. If you crash a SS prop and trash your gears, it doesn't mean for sure that an AL prop would have spared the gears. Possible? Sure, but no way to know.
 
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Home Cookin'

Fleet Admiral
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May 26, 2009
Messages
9,715
Re: Replacing lower units and stainless props

dingbat, where you and I boat, over sand and mud rather than rocks, SS is more durable for bottom strikes than alum. They don't get as dinged and bent, nor do they wear down. So when considering prop metal for that reason, you have to know what bottom you have. I prefer SS, have never hurt a driveshaft, hit lots of bottoms, seldom spun a prop. Back when I ran my old 18 on the whaler, though, I went through a bushel basket of shear pins!
 

PROPer

Seaman
Joined
Feb 7, 2011
Messages
60
Re: Replacing lower units and stainless props

Fortunately I have never had to replace my lower unit after running aground and I have always used a SS prop. I am sure it happens, but there is no substitute for being aware of your surrounding. I noticed that someone mentioned using interchangable hub like the Mercury Flo-torq. This is a good option for having a sacrificial part to protect your gearcase, but be aware that when those hubs "blow out" you will need assitance returning to port. The rubber in a pressed in rubber hub propeller or a rubber interchangable hub like the Rubex hubs will provide protection for the gearcase and still give you the ability to "limb" into port without a tow.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Replacing lower units and stainless props

I noticed that someone mentioned using interchangable hub like the Mercury Flo-torq. This is a good option for having a sacrificial part to protect your gearcase, but be aware that when those hubs "blow out" you will need assitance returning to port.

You can also buy just the hub kits, and if you blow one out, you can replace it on the water. IF you can reach it.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Replacing lower units and stainless props

Thank goodness just hitting bottom doesn't ruin a gearcase. Us flats fishing guys would sure be in a mess if it did! We can wear out a ss prop in pretty short order but the gears hold up, no problem.
 
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