400 Verado propshaft breakage

[conmax]

Recently, 3 west coast cats have broken propshafts. One is a 28' Nordic which I was told has broken 3 shafts. The other 2 are Eliminator speedsters, 1 28' and the other a 27' which broke last week. The 2 Eliminators broke while getting on plane. Of course the props are gone as well. The shafts are broken where the splines begin. From the one 27 that I saw this week, it appears that the shafts are 2 piece with the splined end welded to the main shaft. The 28' speedster has been broken for 3 months with Merc debating what to do. You would think they would replace the lower and the missing CNC 34" cleaver and get the customer going again.

i would like to know if other twin engine fairly fast boats have experienced breakage. With Merc using these motors in offshore racing, it would make sense that those larger boats running offshore would expose any weak propshafts.

Do any readers know of similar failures.?

[stoker2001]

yup,hears first hand from WC about Paul Wallners AKA "bully" TWO lost CNC blades at bottom:(blows my mind that mother merc would consider using two-piece welded shaft in that application??word has it they kicked down for both of Pauls wheels..

[AZMIDLYF]

Xcats using the same prop shafts?

[noli]

.

AZ, I did a quick scan in Google and FB, nothing came back with reference to 400ROS(XCat) breaking propshafts.



The Predator Widebody just started water testing this week. Will let you know if we have any issues with broken propshafts. We're working with MAX5 Mercury props to get a baseline, not CNC yet.

These MAX5 props are $1,700 each. It might be wise for Predator to stay away from CNC props for now. At $5,200 each CNC prop, that would be painful to lose.






.

[stoker2001]

.

AZ, I did a quick scan in Google and FB, nothing came back with reference to 400ROS breaking propshafts.



The Predator Widebody just started water testing this week. Will let you know if we have any issues with broken propshafts. We're working with MAX5 Mercury props to get a baseline, not CNC yet.






.
nobody boats like Paul in his 28' Nordic SS!!I doubt racers even punish his equiptment like him..but rest assured he broke two without hitting anything this last summer

[AZMIDLYF]

nobody boats like Paul in his 28' Nordic SS!!I doubt racers even punish his equiptment like him..but rest assured he broke two without hitting anything this last summer

Agree^^ seen videos of his runs and he definitely enjoys his boat. :cheers:

[noli]

nobody boats like Paul in his 28' Nordic SS!!I doubt racers even punish his equiptment like him..but rest assured he broke two without hitting anything this last summer
.



I believe you, I was referring to the 400ROS and not the 400R



400ROS 15" mids (racing motors)
387463

400R 20" mids (consumer)
387464



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[JPEROG]

The race guys are not loading those props as hard as the consumer "heavy boats". Wait until we get guys running them in rough water with loaded down boats like the Performance Boat Center Doug Wright 36 is being exposed to. My guess is that the first weak link will be made really obvious. Its all part of going fast and pushing into new territory for consumer performance sales. We are very lucky that Mercury is willing to do it, without them we would never see these opportunities. The down side is the cost of the propellers laying on the bottom along with the warranty claim cost that needs to be recouped by the company at some point. The 300XS continues to be a great motor for the money and simplicity http://www.screamandfly.com/images/icons/icon14.png.

Joe

[hoser]

That motor would look so badass on my 21 superboat
387467

[noli]

.


If I understand the issues correctly, prop shafts breaking at the fusion weld is fixable I think with the help of after-market metallurgists.

The 400R has a 1 year warranty. I think the door is open for specialized metal fabricators who can make (steel) billet, 1 piece prop shafts for the post-warranty period.





.

[JPEROG]

My guess is that it will be solved in house. They can't afford to keep paying big warranty claims for an extended period. First it was the props throwing blades, then we build stronger propellers, now its the prop shaft, whats the next weak link?

Joe

[WILDMAN]

The 400R 21 Liberator I just finished, broke the shaft off while getting on plane. It had 7 hours on it. Lost an $1800 Max 5 prop. Mercury gave me a new gearcase and prop. I have also broke off two shafts on 300xs motors before. Both times were getting on plane.

[JPEROG]

The 400R 21 Liberator I just finished, broke the shaft off while getting on plane. It had 7 hours on it. Lost an $1800 Max 5 prop. Mercury gave me a new gearcase and prop. I have also broke off two shafts on 300xs motors before. Both times were getting on plane.

Yes but you have had a hundred XS motors and only 1 400.

Joe

[WILDMAN]

YUP! I guess that would be 100% breakage then on the 400's!

[noli]

.


Propshaft breaking on a 21 in a lake can't be due to load

That rig seems to be a lighter rig than what most users of the 400R would have that motor on





.

[J.P.]

The older OMC V8's used a 2 piece until I think 88 or 90 and used to break those. They fatigued over time and always seemed to snap when you were just cruising taking it easy.

[J.P.]

Mercury must be using the same metal they make the Bravo gear sets with.

[Steelborn]

I can't believe they would weld shat out of 2 pieces, as a welder I don't think they would be doing it, it must be either bad stainless or something wrong with assembly or stressing point...

[RADER]

That's the problem

[hoser]

That's the problem
Chinese stainless

[Toffen]

Hi,

I had a 350 Sci for 5 years with no issues running the propshaft 2,5 inches below at WOT. I sold the engine this spring, and the guy ran the propshaft even or higher than the bottom (tunnell) using a water pickup. The propshaft snapped off just as the above picture.

I have a 400R now with a Sportmaster. I have experienced no issues. 85 hours this season. Propshaft 3 inches below at cruise and 0,75 inches above at WOT.

Maybe running high getting on plane is an issue. NorTech has sold a bunch of these motors. I will ask if they have experienced any issues. I know them well.

Cheers Toffen

[noli]

.

This is interesting.

Toffen, the gent who purchased your motor, does he have a hydraulic jackplate?






.

[Toffen]

[QUOTE=noli;2990033].

This is interesting.

Toffen, the gent who purchased your motor, does he have a hydraulic jackplate?


Hi!

i will check. I presume so. He has a 22 foot cat.

cheers Toffen

[Double Rigged]

The prop shafts are not welded together but more like fused. They have the two parts spinning in opposite directions and they pressed together. It actually melts them together. They are then cut on a lath. Then they have to pass a specific test for load.
Mercury did not want to use a full steel shaft because of rusting around the prop shaft seals. These are a mix of stainless and steel.
This information is from someone who has been at the foundery. Looks like they have some work to do and i am sure they will figure it out.

[conmax]

one of the things Mercury said about on of the failures to an eliminator rigger was that he did not like the way the motors were placed relative to the tunnels. i guess he thought they may too far in. doubt that is the cause, especially since the failures reported occurred while getting on plane a during the mild cavitation that occurs with most props before the hull planes over. the shafts could already be weakened from high x running at over 100 beating up the gearcases. then, when prop cavitates getting on plane, the weakened shaft lets loose.

since the Speedmaster gearcase is designed for surfacing operation, it will be difficult for Mercury to claim users are running the engines too high.

[conmax]

an bit of added info is that the failures have all occurred on twin cats running 34 to 36" pitch props. they were mounted from 2 1/4 to 2 3/4" above the hull bottoms.

[WILDMAN]

My 21 Liberator with the 400 was just a single engine. I also know that one of the Talon 22's with a single broke a prop shaft also

[powerabout]

Spin welding
A great solution
Been on OMC outboards since the 60's
Merc took a little longer.
They did have one piece with hard chrome like an ssm, thats a great solution for a race boat.
Maybe it should be an option to upgrade to?

[Greg G]

The prop shafts are not welded together but more like fused. They have the two parts spinning in opposite directions and they pressed together. It actually melts them together. They are then cut on a lath. Then they have to pass a specific test for load.
Mercury did not want to use a full steel shaft because of rusting around the prop shaft seals. These are a mix of stainless and steel.
This information is from someone who has been at the foundery. Looks like they have some work to do and i am sure they will figure it out.

Do you know if the Foundry is Merc owned or do they use a sub for that component?

[powerabout]

those giant cnc 4 and 5 blades are not helping
Ever had a Sterndrive ssm shaft in your hand, they are huge, how could an outboard do the same job?
The verado will need to go ssm lower and shift in the mid, like the new Volvo outboard...lol

[Chaz]

https://i.imgur.com/mgcCMZvl.jpg

https://i.imgur.com/ffNymJzl.jpg

That's all I gotz to say about that ... :D

[powerabout]

the join is at the high load part

[Double Rigged]

Do you know if the Foundry is Merc owned or do they use a sub for that component?

I was told yes it is their own Foundry. For them to tell boat manufactures to change the mounting of the engines is BS. When you spend that kind of money for motor that is limited in how boost comes on already and to have those failures they need to fix the problem and redesign it. Which i am sure they will. Maybe a 1.62 ratio with smaller pitch prop would work better? But then the acceleration will be even worse.

[AZMIDLYF]

ROS and R use the same shafts?

[home made tunnel]

Coming from someone who works in the steel trades, familiar with many welding processes... Friction welding was a poor choice in this application in my opinion.

Torquing a friction weld is it's weakest point. pulling, OK. Pushing, OK... bending and torqueing, no good.

It's a forging process... not a fusion process.

Orbital GTAW tig welding would have been a much better means for dissimilar metal welding.

[Spectre Powerboats]

My 21 Liberator with the 400 was just a single engine. I also know that one of the Talon 22's with a single broke a prop shaft also

Which one as that? I have 4 of them out there and none of them have broke any.

[WILDMAN]

I thought that someone broke a shaft! Maybe it was a 300! Joe's 300?

[Spectre Powerboats]

I thought that someone broke a shaft! Maybe it was a 300! Joe's 300?

No Talon's that we have built have broke any props shafts (yet.) We have broke a crap load of props on the 300's and 400's, but no prop shafts. A few had 300 seals go out and blew them up that way. I know if you do not follow Mercury's recommendations on X dimensions and set up, you have a good chance of breaking them and having your warranty pulled. I have worked close with Griffy and Joe from Mercury and I can not say enough good about these guys. Mercury pulled the warranty on one of the guys that is mentioned on here (and is a customer of mine) and I talked with Griffy and he re-instated his warranty, covered prop shafts and props, flew out and rode in the boat and talked to them about the set up. Can't get any better than that. Plus we all have to remember, this is the first round with this caliber 4-stroke, so if this is round one, I can't wait for the next rounds to come and they are coming.

[Boble Jakob]

[QUOTE=noli;2990033].

This is interesting.

Toffen, the gent who purchased your motor, does he have a hydraulic jackplate?


Hi!

i will check. I presume so. He has a 22 foot cat.

cheers Toffen

Hi every one, I am the one who got a hold of Toffens old 350 engine and broke the prop shaft after about 4 hours of use.
I had a Stainless Marine jackplate. And the engine was mountet on the lowest point on the lift. The lift was never in use, cause i needed the engine as low as i could get it.
The boat was a Hydrolift CR24 so a catamaran 24. It happend when i accelerated from 0. And just after a few seconds the engine reved hig. And the prop with the shaft was gone.

The dealer said it had never happend before, and was not (at first) willing to admit that it was a problem with the shaft, but my use on a cat. But after some discussion I got a new shaft from the dealer, and at that point the dealer was verry happy and told me this was a new an improved shaft (with i thought was a bit odd, since they actually meant there was no issue with the old one).

But i bougth an sportsmaster house with they build up for me, and the boat has been working great since.


387907
387908
387911
387910
387909
387905
387912
387913
387906

[powerabout]

Coming from someone who works in the steel trades, familiar with many welding processes... Friction welding was a poor choice in this application in my opinion.

Torquing a friction weld is it's weakest point. pulling, OK. Pushing, OK... bending and torqueing, no good.

It's a forging process... not a fusion process.

Orbital GTAW tig welding would have been a much better means for dissimilar metal welding.
how would you make one piece with SS at one end and very hard steel at the other?

[home made tunnel]

how would you make one piece with SS at one end and very hard steel at the other?

Last line of my post... Orbital tig welding. Beveled shafts, weld from the inside-out.
All welding should be done before final machining / turning down.

[powerabout]

Last line of my post... Orbital tig welding. Beveled shafts, weld from the inside-out.
All welding should be done before final machining / turning down.
after a few million shafts I reckon they stuck with spin welding.
When it breaks its usually beside the joint not on it, would tig help that?
its the bending force that gets it and the join is right at the end of the bend

[engineermike]

Or they could make it out of one piece of 17-4PH.

[noli]

Or they could make it out of one piece of 17-4PH.
.


I just googled 17-4PH and got this...cool!


387931

[noli]

https://i.imgur.com/mgcCMZvl.jpg

https://i.imgur.com/ffNymJzl.jpg

That's all I gotz to say about that ... :D
.



Charlie, can you build new shafts out of billet Stainless steel?






.

[engineermike]

17-4PH has nearly the same strength as 4000 series high-strength steels, but the corrosion resistance roughly equivalent to 316 stainless. It's fairly common and available but nowhere near the cost of exotic materials.

[NICE PAIR]

Help a blind guy out ... are these breaking @ the front side of the bearing?

387967

[Chaz]

.
Charlie, can you build new shafts out of billet Stainless steel?
.

I thought I didn't have nuttin to say bout dat ... :D

If you look at that shaft I have and the one from Europe you will see that material has lifted off the surface in the needle bearing area . Mine was wty replacement given to me to use as part of my PVS prop hole drilling fixture . So I don't know it's history other than it's a Verado fat shaft and that they caught it before it chewed the rear bearing completely up and seized or flopped around till it broke .
I like 17-4 , Mercury uses it to build props , maybe even the back section of the shaft and the center section of their stainless driveshafts . I split a 5 lb box with my OMC neighbor a few years ago . It's color and malleability match's perfect for prop repair .

However , stainless can not be carburized ( surfaced hardened ) to the 60+ Rockwell that something like 8620 can in order to survive as the inner race for the needle bearings in the carrier ( as you can see they don't always get that tricky process right ) . It wouldn't work good at resisting deflection the meshing gears would load it with either .

With todays coatings , I really don't see where they would need to continue to stay with stainless beyond the seal package .
They would be better off going to something like 300M which can be machined proud (big) , case hardened , brought to final size by surface grinding and then DLC coated.


Nawww ... never mind , It's lotz cheaper to replace a few lower units and props .. ;)

[AZMIDLYF]

Actuarially...you are correct. ;)

[Chaz]

Actuarially...you are correct. ;)

I learnd dididt @ NASA ... 150+82=105.45kg :thumbsup:

[Chaz]

Help a blind guy out ... are these breaking @ the front side of the bearing?

387967

Mr. Pair ,

What else do you see wrong with that picture ... ?????

Here's a hint , It's square , and about 1/2" long ... :smiletest:

[FORBESAUTO]

Yo sho is a smart fellar rite ther

[NICE PAIR]

Mr. Pair ,

What else do you see wrong with that picture ... ?????

Here's a hint , It's square , and about 1/2" long ... :smiletest:

I haven't even seen a 400 lower with the prop off yet, the lock tab is wrong and the carrier looks to be rotated. (shouldn't the drain be @ the bottom?)

I have been wrong .......... more than once. ;-)

[Chaz]

I haven't even seen a 400 lower with the prop off yet, the lock tab is wrong and the carrier looks to be rotated. (shouldn't the drain be @ the bottom?)

I have been wrong .......... more than once. ;-)

Me too .. no matter what Forby says ... :D

Stick a Wrigley's for you sir !
There's a little keyway at the bottom between the case and carrier .. They like to roll over and embed themselves in the case ... :eek:

[engineermike]

Hey Chaz, I'm impressed! I didn't realize the shaft was being used a bearing race. That makes it a bit more difficult. I haven't dug into it, but I would think 17-4 could be surface-hardened by nitriding or boriding. That may not harden deep enough to manage the herzian stresses though.

What about using a cheaper stainless shaft (2205 comes to mind) with a carburized steel sleeve in the bearing area?

Or just hope mercury gets their weld figured out.

[NICE PAIR]

Me too .. no matter what Forby says ... :D

Stick a Wrigley's for you sir !
There's a little keyway at the bottom between the case and carrier .. They like to roll over and embed themselves in the case ... :eek:

Thank-you, would you think less of me for asking for 2) sticks of wriggleys (you know double your wriggleys-double your fun) ;-)

[powerabout]

Tapered roller bearing, preloaded shaft and all that
But that would mean a bearing carrier that probably couldnt pass any exhaust

[Chaz]

Hey Chaz, I'm impressed! I didn't realize the shaft was being used a bearing race. That makes it a bit more difficult. I haven't dug into it, but I would think 17-4 could be surface-hardened by nitriding or boriding. That may not harden deep enough to manage the herzian stresses though.

What about using a cheaper stainless shaft (2205 comes to mind) with a carburized steel sleeve in the bearing area?

Or just hope mercury gets their weld figured out.

Multiple contact area's simultaneously ... How about the hysteresis of multidirectional forces being applied in random oscillation to a compromised sub par component .. ;)

I.E. The *&^%&8 thing is hollow up front where the shift junk slides back and forth thru the &^$%$& bearing mount .

The &*^%%& *&^%&* tries to shove the &^$* pinion up thru the &%#$@% top and the driven gear is tryin to bend the ^$%%&* shaft because of the "diametric of pitch" ... err ... angle on the *&^%^ *&*^% gear .

Better be a pretty hard *(*&^^%%&*( *&%^%&#$ to keep all that &$%$%&^ running straight . :D

Mercury said that a 24" pitch propeller is the most efficient compromise between thrust and parasitic drag .
One more tooth on the pinion of a 1.62 is a 1.48 .. just sayin .. :thumbsup:
They must have forgotten their own word's of wisdom . Since they build props that are suitable to also be run on a Mississippi paddle wheeler ... as most alluded to the fact that they were under acceleration when the shaft broke , the prop didn't know if it was to take a slice or just slap the surface ...

https://tse4.mm.bing.net/th?id=OIP.XAuFzovefsg9InBucuX_bgEsCi&pid=Api

[Chaz]

Thank-you, would you think less of me for asking for 2) sticks of wriggleys (you know double your wriggleys-double your fun) ;-)

I fully understand .... :thumbsup:

It's why I don't drink , I always thought "happy hour lasted at least 3 days " ... :eek: :D

[Tom Foley]

The 400R 21 Liberator I just finished, broke the shaft off while getting on plane. It had 7 hours on it. Lost an $1800 Max 5 prop. Mercury gave me a new gearcase and prop. I have also broke off two shafts on 300xs motors before. Both times were getting on plane.

Absolutely unacceptable to release products like this . Imagine if you HAD to get on plane quick to avoid something etc and it failed . It's great they covered it but the lost time on boats due to part failures like this can never be recovered . Hopefully they will develop parts that work .

[mn808gade]

may i ask,what tool is that in your hand -th

[noli]

.


with all this shaft breaking, hope folks are taking advantage of the 3 year extended warranty on the 400R?


...just run to your bank and get the money out that's all :)



388074

[Chaz]

may i ask,what tool is that in your hand -th

A spring loaded depth / diameter micrometer .

[lightspeed]

We just rigged 2 32 doug wrights with these motors so far no problems about 15 hrs so far

[JPEROG]

We just rigged 2 32 doug wrights with these motors so far no problems about 15 hrs so far

Another sign of how efficient the 32 is. The cases don't need to be as high as others to achieve the low to mid 120 speeds that they are seeing. I know Eve has a decent amount of time on his and has not broken one yet even with his wfo running habit.

Joe

[Double Rigged]

It's all that extra HP from the computer flashes those west coast guys are getting to make their boats faster LOL! :D

[NICE PAIR]

It's all that extra HP from the computer flashes those west coast guys are getting to make their boats faster LOL! :D

I thought it was the hard water. ;-)

[mn808gade]

thanx-th

[AZMIDLYF]

Think it's the air myself...

WILDMAN, was the 400R gearcase running higher than all the 300XS motors on the Liberator?

[WILDMAN]

Yes, it was 1 1/8" higher. 2 3/8" above the bottom

[JPEROG]

I am really surprised with all of the shaft failures out there that they haven't lost any on the 36 Doug Wright at Performance Boat Center. They have put just under 2000 miles on it and I swear that Myric tries to break it. We ran the living s**t out that thing like it was our last ride ever. That being said, maybe there was a process fault for a period of time. Its definitely an expensive mystery that Mother Merc has to solve.

Joe

[conmax]

don't really have much new info. mercury did replace the lower on the 27 speedster under warranty and the boat has now been delivered.
bob leach, owner of eliminator was told by some metallurgist that 300m material would be stronger just like our Chaz said.
the broken shaft lower that i saw at eliminator also had the seal and bearing wiped and hogged out. this could easily happen and likely has once any propshaft breaks.
merc still hasn't warranty replaced the one that failed after about 1 yr on the very fast 28. that boat ran 134mph with 36" cleavers. according to the owner, 36's are too big for overall use on that boat. sluggish to plane and accelerate. ok with lite load on cold day.
these boats were all set up between 2 1/4 to 2 1/2 above the bottom. a long straight edge between the last few feet of the bottom to the center of the nose cone was used. of course, the notched was above this by several inches. as long as other boats are set up the same distance from the bottom, it should not matter if they have lower transom like the DW race boats. the props should see about the same forces if mounted at the same height. what could make some difference is the distance between the engines and the tunnels. i expect that if the hull or "y" axis mounting were different, it would result in more or less force transmitted to the shafts.

[Bullhead Bully]

yup,hears first hand from WC about Paul Wallners AKA "bully" TWO lost CNC blades at bottom:(blows my mind that mother merc would consider using two-piece welded shaft in that application??word has it they kicked down for both of Pauls wheels..

Hi Kevin, I haven’t logged on in a bit. Thanks for thinking about me. LOL when it comes to breaking stuff. I seem to have a reputation going that I have to uphold. To answer a few questions. Yes mercury took great care of me spent a lot of time working with me and explained the way the gearcase is designed that it is a carbon steel/stainless steel two-piece friction welded shaft due to the design the internal components and how it shifts need to be made of carbon steel ( as are all other my career outports from what I understand ) I’m an engineer and building gear boxes is not my forte so I will leave it to them.
Keeping the vibration out of the gearbox is key. My propellers were spinning in at that time they were getting dirty water coming off the tunnel. By changing rotation and doing a few other modifications it cleaned up the water going to the gear case dramatically. Time will tell how it works. But again many many thanks to mercury. They’ve been very helpful and have completely taken care of the issue for me. For now. Let’s hope forever.

By the way. New 22 Talon and new 28 SS Nordic on the way. Three more 400s splashing soon 👍👍👍

[powerabout]

I wonder how hot the oil is getting and is that a difference in the different boats?
How does the propshaft roller look in the failed cases?

[MODVP22]

17-4PH has nearly the same strength as 4000 series high-strength steels, but the corrosion resistance roughly equivalent to 316 stainless. It's fairly common and available but nowhere near the cost of exotic materials.

Interesting you mention that. I work for a medical device manufacturer and almost all of the instruments have gone from 316 to 17-4

[powerabout]

17-4, OMC v8 mounting bolts

[baja200merk]

Sweedcat has been posting broken shafts and broken props. I’m sure the ros has a few less clicks on the torque management in the tune.

the Fat shaft I broke let go right behind the forward Gear. Case was off a 200hr 250xs lasted about 50 miles on a Box stock 200ho only over 100 a few times on a 500lb t3. You can see the spin weld in the break on mine. Must be some kind of manufacturing screw up. It is the 3rd redesign of a verado case in only a few years.

[powerabout]

the spin weld join is after the reverse gear I thought?
Perhaps they need to go to the OMC style of having 2 separate pieces?

[baja200merk]

Sweedcat has been posting broken shafts and broken props. I’m sure the ros has a few less clicks on the torque management in the tune.

[powerabout]

cant find sweedcat but the photo of the busted shaft in post #39 on on this thread shows a failed roller. I wonder if the case had water in it before?
Maybe they need to redesign to allow 2 thin rollers so the shaft can bend?

[Capt.Insane-o]

These cases don't have needle rollers, they use cone and cup.

[powerabout]

then what the wear on the photo of the shaft behind the seal area post #39?
are we talking HD offshore box or fat shaft sportmaster?

[Capt.Insane-o]

2 seals and the end of a tapered roller bearing.

[powerabout]

2 seals and the end of a tapered roller bearing.
So it looks like the taper roller seized and then the shaft turned in the cone and then shaft snapped at the step?
Hard to believe?

[Capt.Insane-o]

Mercury has never anchored the bearing carrier properly, they relied on a minuscule key way or a thin piece of stainless tab. Once the bearing carries starts moving around the end is near, What aggravates all this is the props coming loose on the shaft. As much two dissimilar metals "fused" together and put to one of the most punishing duty cycles there is.

[powerabout]

Mercury has never anchored the bearing carrier properly, they relied on a minuscule key way or a thin piece of stainless tab. Once the bearing carries starts moving around the end is near, What aggravates all this is the props coming loose on the shaft. As much two dissimilar metals "fused" together and put to one of the most punishing duty cycles there is.
Time to start thinking about a better way to create an outboard gearbox.

[baja200merk]

Here’s where mine broke. The one side of the break sure looks like weld the other side is about 1/2” further forward and doesn’t look like it has any weld. This case had low hours I had a small 30 cleaver on it and had only been 106 on limiter with a 200. There was zero water, all bearings were in perfect condition when it was torn down. It somehow managed to mushroom the lower driveshaft enough to split the pinion nut in half. The nut came out in 2 pieces when the carrier was removed.

http://i408.photobucket.com/albums/pp163/hondacr8288/2EE1EEC6-3E9C-407F-9269-1B71A0246989_zpslyrxwhfb.jpg (http://s408.photobucket.com/user/hondacr8288/media/2EE1EEC6-3E9C-407F-9269-1B71A0246989_zpslyrxwhfb.jpg.html)

http://i408.photobucket.com/albums/pp163/hondacr8288/758AA53F-6C8A-48E0-8C07-6BCF643FFBF2_zpsnahfcmt6.jpg (http://s408.photobucket.com/user/hondacr8288/media/758AA53F-6C8A-48E0-8C07-6BCF643FFBF2_zpsnahfcmt6.jpg.html)

http://i408.photobucket.com/albums/pp163/hondacr8288/BE092465-43AF-4C44-AF43-AC541618E804_zps123zvlgg.jpg (http://s408.photobucket.com/user/hondacr8288/media/BE092465-43AF-4C44-AF43-AC541618E804_zps123zvlgg.jpg.html)

[powerabout]

the join is way back between seals and carrier roller.
Trying to keep the box short and having the exhaust in it is a compromise.
Perhaps trying to get the dog and splines to work on a 17-4 shaft with a sleeve for the fwd roller and a step out back to go to a tapered roller like the 400 might work?
Then its one piece
Single piece of steel is much easier but not for the average fisherman.
Time for weismann to do an outboard

[Capt.Insane-o]

That's a common place to break after a party shift or using a solid hub prop or the fwd to reverse on the trailer before the big heavy bravo or mirage comes to a stop.

[rude tim]

I would hate to see one of these shafts brake at speed on a twin cat.

[Trimmed Out15]

At least you had a nice view on the tow in

[JPEROG]

Rumor is that Mercury has the solution for this problem and its solution is close to being in production. These are really expensive warranty claims for them to deal with.

Joe

[AZMIDLYF]

These breaks generally occur when coming up on plane?

[JPEROG]

They know Paul on a first name basis. How many of the props have you been able to recover?

Joe

[WILDMAN]

I broke two on 300XS's and one on a 400. Two broke getting on plane and one broke 15 seconds after.

[JPEROG]

I don't think that there is going to be welds in the future and this problem should go away. Think of how much this has cost nation wide over the years-it must be a big total $$. Once again we are lucky to have Mercury backing us up on these issues and losses.

Joe

[baja200merk]

I broke a fat shaft between the forward and reverse gear. Some how didn’t lose the prop but it managed to trash everything in the case. The pinion nut fell out in two pieces behind the carrier also mushroomed the end of the driveshaft .

[Capt.Insane-o]

Yay, love that warm and fuzzy feeling especially when I turned out a dozen of these things this spring.:nonod:

[baja200merk]

I have 5 to build. 3 are small shaft 1 is another of mine. Apparently they had a bad run of 3.0 stuff maybe the same happened with verado

[CUDA]

A little non destructive testing goes a long way .

[Capt.Insane-o]

I have 5 to build. 3 are small shaft 1 is another of mine. Apparently they had a bad run of 3.0 stuff maybe the same happened with verado

If they're not catching on fire the props are falling off.

[NICE PAIR]

Is anybody building bullet proof prop shafts for 300XS Sporty's ?

[baja200merk]

I’ve broken 2 carriers in two different cases one 2.5 one 3.0. Switched all 3 of mine to billet from mad efi.com now. Some of these guys ride around with 36+p props (jperog) and have had no issues with carrier. Every improvement can save your weekend especially when your 80 miles from the ramp getting lunch.

[conmax]

Haven’t revisited this thread in awhile. There have been more posts so the failures must be continuing.
When I dropped off my 28 a couple of weeks ago, a rigger told
me he had another failure on a 27 that he was testing. Merc told him to use Max 5 instead of CNC because they cavitate more while planning. All his failures have occurred during planning. Most have covered lost props. In at least one case they did not because they had told the customer not to run CNC anymore and he did.

[Hot Shot Merc]

https://www.youtube.com/watch?v=wYmYtDgTf14

[conmax]

Saw that propshaft. Must be stronger than a welded piece. Trouble is, 400’s are almost too new for a non merc solution. Imagine one of these failing and asking Merc for help. Best just to let them keep replacing under warranty until they come up with a solution. I doubt that Merc will replace under warranty just to prevent failures. Guess that would be a recall. Other than downtime, risk is that they won’t replace your expensive prop since it didn’t fail; just sunk!

[whipper]

.


I just googled 17-4PH and got this...cool!


387931. We have some variable speed pumps with 17-4 shafts at work turning large impellers 6000 rpm with consistency loads around the 4.5 range running wide open 24/7 for years with zero failures to shafts. Impellers is another story.
Seems like the prop shaft failures will be around for a while until they do a major upgrade to the gearcase components to Handel the application a lot of these motors will be used for. Gearing and aspect ratios may need to be considered to accommodate these larger pitched props.

[powerabout]

I still think they will be forced to go shift in the mid and that will allow bravo type lower on large outboards
The engine price is way up there now another $1k nobody will notice.

[NICE PAIR]

I still think they will be forced to go shift in the mid and that will allow bravo type lower on large outboards
The engine price is way up there now another $1k nobody will notice.

I'm thinkin another k or two people would notice me rowing my Skater. .... Maybe not. ;-)