transum leak merc

[atwillfarms]

I have a 78 Cobalt that is in decent shape (but a money hole). I recently left lower unit down while on trailer, dragging on asphalt, sober but dumb. I now have a transom leak, coming out while on trailer, on bottom of lower unit. Question is does the lower unit & engine have to be removed to repair leak? This boat is seeing limited use, how much can it be used prior to having transom damage? As you can see I am struggling with this boat to repair or salvage, any opininions?:facepalm:

 

[jigngrub]

Re: transum leak merc

ALL boats are money pits, and I/O's seem to be the biggest.

You should check your transom for rot, the pics look like it's a prime candidate... and yes, this is going to be even more money.

What year model is your boat and has it ever been gutted and restored?

 

[atwillfarms]

Re: transum leak merc

ALL boats are money pits, and I/O's seem to be the biggest.

You should check your transom for rot, the pics look like it's a prime candidate... and yes, this is going to be even more money.

What year model is your boat and has it ever been gutted and restored?

A 1978 year model. I have owned over 20 years. No it has never been gutted & restered, only cosmetics like seats, carpet & upholstry. Several years ago I replaced chevrolet 305 ci engine with a 350. Over the years, have replaced several lower units prior & after engine swap. This year I spent a considerable amount of money, replacing everything on trim & other miscelaneous items. I felt like had in pretty good shape until this stupid mishap.

As one might see, I am struggling with where to go with this because of the following /value of boat, even in good condition/ wife not interested in boating/ myself almost always owning boat not wanting to let go/ having it professionaly done, not having skills & equip/ how to dispose of boat.

Sometimes one has to cut their losses & move on. I am asking opinions & advice on how I should proceed before making a rash decision. I am keeping up on my colleauge with "transom leak" with much interest. Thanks for all the support & advise.

 

[jigngrub]

Re: transum leak merc

If you do have rot and can't do the restoration yourself your best bet would be to sell the boat as a project boat or part it out... or part it out a give away what you can't sell.

Having a resto done professionally wouldn't be worth the money. You could buy another newer boat in better condition for the price of a resto. There's also the issue of paying good money to have the job done and having someone doing a halfassed job.

I don't mean to sound so negative about this but we see a lot of rotten fiberglass boats on this forum, and also see people getting ripped off paying good money for a bad repair job. We also see people paying good money for fiberglass boats that're supposed to be water ready only to soon find out that they have bought a rotten mess.

Since you've owned this boat for 20 yrs. I would say you've gotten your moneys worth out of it and it may be time to move on. I've always considered getting rid of an old boat a darn good excuse to upgrade to a newer better boat.

 

[atwillfarms]

Re: transum leak merc

If you do have rot and can't do the restoration yourself your best bet would be to sell the boat as a project boat or part it out... or part it out a give away what you can't sell.

Having a resto done professionally wouldn't be worth the money. You could buy another newer boat in better condition for the price of a resto. There's also the issue of paying good money to have the job done and having someone doing a halfassed job.

I don't mean to sound so negative about this but we see a lot of rotten fiberglass boats on this forum, and also see people getting ripped off paying good money for a bad repair job. We also see people paying good money for fiberglass boats that're supposed to be water ready only to soon find out that they have bought a rotten mess.

Since you've owned this boat for 20 yrs. I would say you've gotten your moneys worth out of it and it may be time to move on. I've always considered getting rid of an old boat a darn good excuse to upgrade to a newer better boat.

I think very good information. One question no one has answered is assuming there is no transom rotting, does one have to pull both engine & lower unit to repair the above described leak? It is coming out around bottom of lower unit, where there was once some caulking. Being ignorant of subject, it sounds like gaskets & seals will probably have to be replaced.

 

[H20Rat]

Re: transum leak merc

I think very good information. One question no one has answered is assuming there is no transom rotting, does one have to pull both engine & lower unit to repair the above described leak? It is coming out around bottom of lower unit, where there was once some caulking. Being ignorant of subject, it sounds like gaskets & seals will probably have to be replaced.

not to sound negative, but I"m tending to agree with the posts above... You are in for far more than gaskets/seals. The reason it is leaking is because something flexed far too much, and that something is a rotten transom. Yes, you could probably pull the entire lower unit on and get it sealed up with enough 5200 that it won't leak, but that is not a repair, that is a bandaid to keep you from sinking.

 

[fishrdan]

Re: transum leak merc

It's probably transom rot that cause it to flex enough to cause the leak,,, but you are not going to know unless you get into it. Drill some exploratory holes in the transom, low, inside the boat, close to the lower bolts, to see if there is rot. Dry yellow shavings = good, black moist shavings = bad. Seal the holes up with 3m5200. If smacking the pavement broke the lower gimble housing bolts this could cause the leak. Those bolts are a special alloy and pretty weak for their size, prone to corroding/rotting the bolt on older boats, especially in the presence of wet (rotten) wood . If the bolts were corroded to 1/2 their diameter, the smack on the pavement could have snapped them. I couldn't see the bolt (or should I say anode) in the pic, not sure if it's the poor pic or it's gone. The bolts have a screw-on anode on the end. The anode is about 1.5" in diameter with a rounded end, located next to the trim hose manifold on the gimble housing.

On my 73 Mercruiser with a rotten transom, 1 of those bolts was rotted clear through, with corrosion and gunk holding it in. The other easily snapped in 1/2 when I was trying to remove the nut. I removed 1/2 the bolt with the nut still attached from the inside of the boat, the other 1/2 of the bolt from the outside of the boat... The 73 also used a foam gasket between the gimble housing and transom that had long ago dried up, shrunk and lost it's sealing ability. it was "barely" covering/sealing anything by the trim manifold. (I'm not sure if they used the same foam gasket in 78, but.......... The gasket is cork/rubber now.)

The repair is going to be a real PITA as the drive needs to come off, engine out, transom shield (plate) and gimble housing off, replace gimble housing gasket and put everything back together. Could do it in a weekend IF the transom isn't rotten... (kind of doubtful.........................)

 

[atwillfarms]

Re: transum leak merc

Thanks for info, will do some testing in transom. If the transom is good approx. how much would a professional mechanic charge to repair plus parts?