AFDD

Transom plate replacement, 327 SSX (mercruiser 8.2)

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Local dealer principle has said nearly all the 327 SSX he sold required transom plate replacement due to failure where a hose passed through the hull. The 2012 model I'm looking; he's suggesting allow for engine out repairs $$$$

Is this a real reoccurring issue with the  mercruiser installations

cheers 

 

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There should be an upgrade kit that replaces the hose with a plastic tube, also allowing all wear items to be serviced from the drive side in the future. Engine out to replace these hoses because the flange where they terminate are on the engine side of the transom, directly in back of the engines. With salt use, the transom plates can corrode these hoses shut, and the studs on the flanges can shear when attempting to replace (happened to me on my last boat with a Merc).

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Ok, I'd heard the hose gets compressed due to salt crystals, but local dealer said he had an in situ fix ?

He then said that as you noted the transom plate will still corrode where a hose connects and thus necissates removal to replace the transom plates. I can't quite understand how Mercury can in this day/age design such poor equipment.

The dealers quoting $10k for both out, fix & service? 

Im yet to buy this boat so if this is necessary the $ go down.

 

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Is this the condition sometimes referred to as "Bravo-itis".  My '08 270 Sig with 8.1 Merc & B3 had a cooling water pick-up hose that had corroded closed. If was replace by a local indy mechanic without removing the engine.  Now, however, I have what I consider to be excessive water intrusion at the stern.  Perhaps I have a corroded transom plate?  Is water intrusion a symptom of transom plate corrosion?

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I should say that "I can see why they quote engine out" because of where the connection points are, directly behind the engine, and whether the repair can be done with engines in is highly dependent on engine bay access and size of engine.

Big block seriously reduces available space around the engine, especially with two of them.

Technically, if there is enough space, and the studs don't break, this can be an engine-in repair, but sometimes things can be easier and cheaper pulling the engine rather than fighting the lack of space to work in.

As far as I understand, the plastic tube upgrade is the fix, don't know about having to replace the actual transom plate. But I suppose that depends on how bad the corrosion is.

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Time for some good  " In field changes.  "  By you big block guys.   S S threaded pipe nipples? S S over sized washers. Closed cell gaskets. & nuts.  Mechanics are better than many engineers.  They correct the boo boos for you.  A hole saw with a plan. Done

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I'm still being told it's the transom plate that fails and weaps' necessitating engine out for replacement,  another mechanic said it was normal 5+ years on the mercruiser 8.2?

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I checked out a more drive line related forum and the issue is very real with many claiming the mercruiser were fine in fresh water but abimsal in salt, I can only hope later models had this resolved but the rig I'm looking at is 5 years old has seacore yet suffered the salt build up and transom plate failure. 

This boat spent 18months in salt and 4 years is dry stack, the dealer advised that's about right?

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Well here is the outcome, after a lot off research and inspection costs both mechanical and a survey this just isn't my boat. I've written it up as a bit of a story so maybe this will assist others in there search for the right boat. Location is obvious and dollar are A$.

 

A tale of two boats - Chaparral 327 SSX

Both boats were of USA manufacture in 2012, both identical in specifications and endowed with dual Mercruiser 8.2 litre stern drives with bravo 3 legs. Both engines are closed loop cooled (fresh water) which includes manifolds. Both were delivered through the same Australian dealer.

These boats are day boats, featuring a capacity of up to 16 people, they feature concealed heads, hot water shower facilities, double bunks, cooking facilities and more, there's a genuine opportunity for these boats to live permanently on the water. Whilst strictly not a trailerable boat they are seeming a towable boat in the USA. 

Boat A was delivered to Melbourne, anti-fouled and lived in Geelong for nearly 18 months, it then lived in dry stack storage in Melbourne.

Boat B was delivered to Sydney and lived in a Seapen, it then travelled north to the Sunshine Coast still in its Seapen.

At around 4- 5 years of age boat A received a motor out service which necessitates removing the entire rear section of the boat in order to access the internal transom plates, the corrosion on the transom plates being the reason the motors had to be removed. The total cost was reported to be in excess of $30K, as "while you at it you may as well"?

Boat B which lived in a Seapen was showing signs of similar transom plate corrosion at around 5 years of age, it to was in need of an engine out service to replace the transom plates. Similar scenario similar costs expected.

Environments; 

Boat A lives in relative dry mild climate.
Boat B is a hot humid climate, loadS more train.  

Discussions:-

You could assume boat B which who's hull and drive train were protected from the elements should not have suffered the same corrosion.

Service agents reported that as the transom plates were subjected to  seawater and subsequently allowed to dry that it is susceptible to corrosion.

The legs on boat B were blistered, indication corrosion under the paint.
The transom plates on boat B we're exhibiting a white powder indicating corrosion underneath. Services agents reported visible external aluminium oxide (corrosion) would suggest a significantly higher level of corrosion could be expected inside the transom plate.

Failure of the transom plate in respected of corrosion would lead to the ingress  of water into the engine bay, initially slight, not simply making a mess but potentially sinking the boat should it be significant it also has the potential of wetting expensive electronic components with subsequent costly repairs. - not good!

Who's responsible?

In the first instance the motor manufacturer must be considered responsible, why would components be specified that will react in such a fast manner with seawater given the component is built to work in such an environment?

In the second instance the boat manufactures can be liable for poor specification and secondly bad design which Requires such a major amount if work in order to access a failed component. (Cost cutting)

After 2-3 years all warranties are void.

In both cases the owners were reported as caring, sparing no expense on maintenance.

Boat B living in a Seapen was fitted with fresh water flush facility, but service personnel doubted it would adequately flush the legs. Secondly living in a Seapen made it virtually impossible to flush the legs by fitting ears. The hull was in excellent condition.

Comments suggested that flushing from the ears may not be possible by normal tap pressure, suggesting that such an exercise maybe futile anyway.

Boat A could have had its engines flushed from the legs, but did it, boat A also did not have fresh water flush fitted.

Suggestion were that had either boat lived in seawater full term that the transom plates would remain wet and possibly not be subjected to oxygen which enhances the corrosion process.

Did the seapen accelerate the corrosion, due to some form of electrolysis, did the humid wet environment mean the hull and leg were nearly always wet or at least damp? 

The manufacturers representative suggested that 5 years is about right for this level of failure? Would that suggest it is an acceptable failure?
It was also noted that all the boats he delivered had this problem and it was a when not if failure!

So what is the conclusion, should both owners simply avoided dry storage in an attempt to reduce exposure to seawater, was it there attempts to look after either boat that caused the rapid failure of the transom plates.
 
Does a Seapen create an environment that enhances corrosion? 
The legs were in poor condition why?

The manufactures rep suggested he altered the polarity of an anti corrosion  device when boats were in seapens.

A common element is that both boats are exposed to seawater, removed from that environment and allowed to air dry, boat A by being totally out of the water in a dry under cover storage. Boat B having a skin* between the hull, (legs) and the seawater.

(*A pump removes the seawater from the skin, rope between the hull and the skin encourages a dry environment or does it?)

Is the motor manufacturer at fault for poor quality in other words the transom plate was not fit for operation in this environment!

Was the boat manufacture guilty if cost cutting, using inferior parts?

Did the delivering dealer under specify the boats for the Australian environment?

Were the owners careless in not adequately flushing the motors?

Result is a lots of unnecessary costs in order to fix a problem, unhappy owners, significant loss of value in the boat due to high maintenance, happy service agents?

Delivering dealer suggested after the repair the issue maybe resolved for at least another 5 years. He wasn't sure?

Ok, what's your take?

Foot note:

At the time of writing both boats have been on the market for 6 months, boat owner A is adamant and holding a high price - he wants his money back. Owner B is desperate to sell having found out he has a problem.

After paying for a survey on boat B I walked away, shattered as I just wanted this!

Lovely boats, but liability isn't an objective I'm seeking.

 

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Why wouldn't a similar boat in Florida experience the same deterioration is my question? Same salt water and similar climate.

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Update.

The dealer said he always disconnects the mercathode when the boats are in sea pens or stored out of the water, seems the Eddie currents may have caused the blistering & corrosion on the legs as the leg touches the Seapen skin thus creating a circuit.

Go figure, both owners have tried to do the right thing only to be caught out, who would have thought isolationing the boat from the water would create these issues.

Had Chaparral designed the 327 with service access in mind there's a fair chance this issue would be a whole lot easier, but as an engineer I'm appalled at the design.

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Not sure how flushing would have prevented this issue, if we're talking about the same corrosion point: where the raw water inlet hose crosses the transom. The corrosion happens around the rubber hose, external to it. And slowly crushes the hose shut. Flushing with fresh water wouldn't touch that area.

Sounds like disconnecting the mercathode system, to accommodate a storage contraption, made matters worse, but you can't fault the designers for an anamoly like that. I don't know how many seapens you have down under, but I've never seen such a product like that in the US, which is the majority of the recreational stern drive market.

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Aussies have Salt Water Aluminum Fungus. ............... I would do a lawsuit on any boat with that problem........Totally unacceptable of a too short of a life span ....EVERY 5 years....  ??

Every 5 years $  10,000 to $ 30,000 .  

Hold on !!!!!!!!!  There is 1 real possibility for rapid corrosion in certain areas / waters................  Severe POLLUTION .  It can create a PH  that will rapidly eat metals like Aluminum.

A..... P H testing of the docking water at different days & times will catch the pollution company. Or bunch of companies 

Check for defective or never installed G F C I  on your dock power outlets.

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