Removing drives, engines and transom assemblies.

Grahamu

Here is a photo of the staining under the stbd transom assy

Grahamu

Another discovery today is the limber holes and the bottom of the transom above the drain plug are not sealed. This might explain the higher readings in the summer for the stringers. Not sure if other 342 are like that.

LaRea

That staining does look like it could be a leaking transom assembly.  And it would not surprise me to see unsealed limber holes.  The drain holes in my 342 swim platform were not sealed.  

Grahamu

The photos show where the leak is coming from and I was surprised to see how rusted  all the studs are. The transom cutout shows no protection including the stud holes.
Plan now is to remove the skin on the inside to see what the condition the wood is in. I am  hoping by exposing it to give it time to dry but Murphy is always around the corner.

randy56

Had a freind that had to remove skin and replace all the wood then re fiberglass. He did take pictures and measurements before. to try and get close to the location of mounts. It was not a Rinker. Hope your in a heated shop. It took some time. We had to sandwich two pices of 3/4 marine plywood together to get proper thickness. Clamped, glued and screwed. 

LaRea

That's odd.  The studs on mine were all bright and shiny - even on the side with severe corrosion on the steering arm.  

Handymans342

What a horrible design flaw

randy56

Your never board when you own a boat.

Grahamu

Hi @randy56 The shop is heated but only to 60F enough for most things to cure. I can put in extra heat during the day  as the electricity is turned off at night time for fire prevention. Have to agree with handyman the transom is subject to the highest stress and yet they took shortcuts. But I have seen it with other brands including Sea Ray. Recently a Sea Ray cost $25,000 to repair the transom because of the same problem. 
And @LaRea the studs that are most corroded are on the drier side. I think there has been a problem with the outer seal of the transom assembly also.

Aqua_Aura

I thought I remembered reading about injecting epoxy into the weakened/rotted wood and it cure inside and strengthen everything? Might be worth looking into depending on how bad it is. 

Handymans342

Don’t look too bad

Grahamu

Skin has been removed from inside transom, wood is solid. Added some warm air in the area to help the drying process, probably 3 to 4 weeks.
@Aqua_Aura yes many years ago I had 40' Pacemaker, solid mahogany, used Git Rot a few times.

Grahamu

Here's the culprit, the pin is totally corroded and ripped the seal. Ordered new parts including a stainless steel pin only $20 more than the standard steel pin.

Handymans342

Good job. Fatal design flaw

Aqua_Aura

Is that the infamous Mercury steering pin 🤨. 

With all these transom assemblies being removed I guess we now see the transom is all wood which seems odd even though I think this is the standard on most if not all boats. What happened to the theory of solid fiberglass below the waterline? 

randy56

That plywood looks great, good news. Sleep will be beter knowing an easy fix.

Grahamu

Removed the 4 house batteries, 8 years old, slight bulging and one leaked. The starter batteries are mismatched. All of them will be replaced with new. The cables will be shortened and new terminals. The negative bus bar on the transom also needs attention.

Grahamu

Made the decision to remove the STBD engine and transom assembly, slight evidence of the steering pin leaking so better to deal with it now. I will be trucking the boat up to Lefroy on Lake Simcoe in the spring and will lose access to  my shop.
To make easier access with the forklift the engine hatch was removed today. Also makes it easier to clean the compartment, won't be painting though as per @LaRea

LaRea

I see nothing out of the ordinary in any of these photos.  The ground bus definitely needs attention.  Is there another one somewhere else in the engine room?  

Is it possible to repair leaking seals on the steering pins?  Or are you replacing the transom assemblies?  

Grahamu

Hi @LaRea I have not seen another negative bus in the engine compartment but I am  sure I will find one at the helm station and the main breaker panel,
Repairs are already underway to the transom assembly, a new seal has been installed and waiting on the replacement SS steering pin. Why Mercury still offers the steel pin is beyond me, It's a$20 difference and the stainless version will not rust which is the root cause of the problem. Photo shows the new seal in place.

Handymans342

You don’t have time to paint the bilge????

reneechris14

So if the studs were the other way around you could take of the assembly with out having to remove the motor. I do understand the issue of corrosion. How about access to the steering pin, set up like the access to the shift fork. Oh I forgot we work on the boat not make the boat so folish of me

Grahamu

@Handymans342 I haven't ruled out painting the engine room, a lot will depend on how it cleans up. The area around the port transom assy cleaned up nicely with degreaser and acetone and I would be happy with that if the rest came up that way. 
The stbd  transom assy is out is as bad as the other side. I am not convinced that the steering pin leak is the only problem, I think the outer seal was compromised.

Handymans342

Yes, make sure you use sealant when reinstalling

YYZRC

Steering arm is in nice condition on that one.

LaRea

@Grahamu how hard was it to replace the steering pin?  Maybe I'll restore one or both of mine and sell them.  

Grahamu

@LaRea, I did not attempt it, I had the Mercury mechanic do it. It takes 6 -7 hours to strip and rebuild depending on how much corrosion there is. Parts are averaging CDN$600.00 (after discount)the bulk of which is the stainless steel pin. There are a couple of special tools required. The bellows were replaced 2 seasons ago and in good shape so I did not replace them. Overall a lot less money than buying replacement units, not sure what a refurbished assembly would sell for.

LaRea

Copy ... I'll sell the hydraulic rams on eBay and probably trash the other parts.  

Grahamu

The major part of this job started because of the high moisture readings on the inside of the transom adjacent to the transom assemblies. As posted both assemblies were leaking from the steering pins and the seals on the outside were compromised. Because the cutout was not sealed the water would be absorbed as it sits trapped by the transom plate. It is now 6 weeks and the moisture readings are starting to drop very slowly. The cutouts will be cleaned up and 3 coats of epoxy applied to seal them.



because the moisture readings tended to spread outboard of the cutouts I decided to remove the swim platform supports, No caulking or very little and moisture has definitely been penetrating the transom as this sits in the water all the time. 



I also checked the trim tabs and rams and they were fine and reinstalled.

Handymans342

Dont forget the drain hole fitting