transom / motor well trim separating and leaking oil

[ferret30]

The top edge of our transom where it drops down to meet the motor well has a sturdy piece of hard plastic trim capping it. It looks like it was originally glued down, but now it is separating from the transom top and there's at least 1/8" gap all the way through for maybe 8". Shining a light inside it's hard to tell what the actual transom top is made of underneath. It looks kind of unfinished, like the fiberglass/core sandwich was just covered with resin.

Is this something I need to take care of as far as allowing water in? Or is it well protected underneath and the cap is just a bumper?

Also, probably a subject for another thread, but I noticed tonight as I was finishing the transducer block project that the large pan head hex drive screw at the bottom of the motor (just above the lower unit) was seeping oil. I'm glad I noticed since I haven't checked the level since I first got the boat. I'm guessing this is the drain plug, and it is already very tight, but it's leaking. Bad sign?

I'll post pictures of both issues tomorrow when the phone's not dead.

[hardee]

I am not a mechanic, but my understanding is that the gasket on that oil drain plug needs to be changed each time it is opened, and if it isn't you stand the chance of a leak. That's from my mechanic, and I believe I have seen that addressed here on the site.

As to the other question, I would have to defer to everyone else first. Good place here, there are folks who do know.

Harvey
SleepyC

[jrassier]

There are o ring seals that fit under the heads of the machine screws that close both the vent(top) and drain/fill(bottom) openings in the lower unit. The o rings are inexpensive and easily removed and replaced. Water can enter the gear case though the same leak the gear oil is coming out of. Water in your lower unit can lead to wear and corrosion.Gear oil should appear translucent similar to new unused motor oil. as water gets mixed into gear oil It will becomes opaque/milky. My 2 cents worth of advice would be to locate the part #'s for the o rings, purchase a fill adapter(hollow bolt that threads into fill/drain hole and attached plastic tubing), and change the gear oil and o rings before running your engine.

[Falco]

JRassier is giving good advice I think. You mention the leak is occuring "above" the lower unit but if it is the gear case vent that too is part of the "lower unit". The lower unit being everything that drops out with the drive shaft when the water pump is changed. You might want to post the picture for us to be sure we understand what you are talking about.

If it is a gear case lube leak, the advice to change out the lube and replace the vent and fill washers is sound. Then carefully monitor for new leaks by checking for visable oil and by draining the gear case after one use to look for either water (it will be the first thing to drain out) or the milky looking lube mentioned. Mercury makes a nice pump filler bottle for its synthetic gear lube (which I highly recommend) which includes the fill adaptor JRassier mentions. Browns Point Marine will have the gear case washers. Wally World carries the gear lube filler bottle - oh I mean "wal mart"

[SEA3PO]

Falco is right, Drain that lower unit....and replace the gear oil and the washer...it should be renewed every time the oil is changed...any Marine Store should have the washer...it is standard practice to replace it so it will be close to where you find gear oils... at least it is at West Marine..where I buy my gear oil.

I absolutely would address that void in the transom quickly before it gets any worse .. take it to someone that works with fiberglass boats as a profession.

Joel
SEA3PO

[thataway]

The plastic cap is "glued" down with either Bostic or urethane sealant. The top of of the transom probably does have resin on it. There should be layers of fiberglass--and resin. This is where the hull to deck joint is covered on top of the transom. There can be leaks, and breakdown of plain thickened resin. On the 25 I redid the transom on, this was a problem.

In your case, I probably would pull the cap, check to see if it is fully intact on the top, and then put the cap back on with black 4200. (This is what we did on the 25, after glassing over the top of the transom.

Agree, with new gasket on each oil change. There is a drain, a fill and and overflow for the lower unit. There is a drain for the oil--but I recollect it is higher than you describe.

[Valkyrie]

We had the same problem on Valkyrie, a 22 cruiser, but the crack came from under the rub rails (aft) and ran under the transom "cap". When I had a local shop evaluate it they found that the top of the transom was not finished or sealed with resin or cloth, but the void was filled with gelcoat!

I contacted the factory, with pics, and they told me to have it fixed, under warranty, and they would reimburse me, which they did. There are NO dealers anywhere near Ohio to handle the problem. I know of three other 22's of the same vintage which had the same problem.

Nick
"Valkyrie"

[ferret30]

It seems like the transom is under attack from all directions! Just so I have a rough idea, how much would it cost to have a decent shop do a transom rebuild if a below-waterline penetration leaked or water seeped in under the cap? I'm guessing the whole core needs to be replaced at once, not just a localized area...

So, is it on the order of $3k? Are rebuilt transoms as reliable as the old ones? Might be worth knowing just in case I have a problem in 10 years, or end up buying another boat, etc.

[Valkyrie]

In our case, water intrusion was not an issue, so I can't really address that, but our repair was $1200 five years ago.

Nick
"Valkyrie"

[journey on]

There is a crack running around one end of the black plastic cap on Journey On's transome. 2 ea comments.

1. I called the factory and they told me some type of Locktite sealant was used. Also, it would be tough to remove.

2. I had a local fiberglass "expert" look at it and he felt that it was a stress crack, caused by water intrusion from under the black cap. His advice was to seal the cap and fill the cracks. BTY, the gentleman said he did Bert Rutan's composite work, which was interesting. Spent some time discussing that.

No guarantee on either comment, but I'm going to follow 2. and see what happens.

Boris

[Montana Kev]

We have a similar issue with the Transom cap popping loose and the temporary fix was 5200. Next step for us is to remove, repair the glass and replace the cap. Here is a link to a previous thread on the subject:
http://www.c-brats.com/viewtopic.php?t=15087&postdays=0&postorder=asc&start=0

Kevin

[localboy]

[primative]

I have not been to c-brats site for a long time ane decided I would today. Guess why? I discovered a transom problem this spring. What a surprise to see this issue being discussed.

Last spring I was anchored in the Columbia for that mythical fish. I pulled out my ice chest to get something behind it at the transom. I noticed a drop of water running down and started looking closer. An old screw hole up on the transom near the junction of the motor well stucture was weeping some drops of water, or rather metaphorically my tears. The screw hole had been a former attachment point for an electrical wire. Being in an upper location I was satisfied to put asmall dab of polysulfide caulking on it. Seeing the single drop of water I picked the polysulfied off and a few more drops weeped out. At this point I had that feeling that had just shifted from denial to post kick to the.....

This fall I trailered the boat to a professional for an opinion. The first thing he pointed out was the beginning of some delamination of the fiberglass at the upper edge of the inside of the transom port and starboard just before the transom trim starts going vertical. With hard thumb pressure you can get the fiberglass to work/spring approx. 1/16-1/8 inch just in the corners demonstrating the delamination. He showed me corresponding subtle short hairline stress fractures in the gel coat on the outside of the transom corners as well. He used a hand held meter to detect water within the transom. I think the most definate concentration he found was near the motor bracket on the portside. He thought the water was getting into the transom through the delamenation described above and not likely the motor bracket bolting holes. He thought the delamination and gel coat stress fractures were a result of motor torque producing flex within the transom. Part of his take on repair was to not just solve the point of entry leaking but to stiffen the transom with fiberglass to prevent the flex. He also suggested a single rectangular washer to span the distance between motor bracket bolts to help distribute the transom stress. He talked about enlarging the holes where the motor bracket bolts go through the transom. If I remember correctly he would use a hole saw to make large holes then fill in with some combo. of epoxy/fiberglass or resin. Then new bolt holes would be drilled through the new synthetic cores so if water ever leaked into the bolt holes in cannot migrate as easily to the plywood. I think he also said the synthetic cores do not compress like plywood does.

The estimate was 2800 to 3200 assuming things are not more advanced damage once we know more, and that it could be less, if I take off the motor so he can concentrate on the skilled labor.

I took the boat for a second estimate and this fellow was more just get the motor off ,tent in the transom area and apply lights to get it dryed out. Once you get it dryed out he thought I could take off the transom trim and cut out a trough within the plywood core area the entire length of the transom in the top edge of the transom approx.2-1/2 in. deep then I could laminate in this core with fiberglass and resin. I'm assuming doing this was his fix for further water entry not so much for controlling the transom flex. He also agreed with the rectangular washer suggestion from the first estimate.

He was not so much interested in an estimate at this point as getting the motor off to see whats going on and if necessary I can drill holes at the inside of the transom where it meets the floor to help drain water if necessary and promote drying. He said the holes did not have to be large in diameter. He said to put tape on the drill bit to create a determined depth to drill so I would not drill through the exterior transom. He said if I did the glass work he could do the paint work. Guessing 600 to 800. He suggested I call the manufacturer to ask about the trim removal.

I called the c-dory manufacturer and the guy who I talked with wasn't sure what my trim was glued with (1999 boat) but suggested I not take it off unless a last resort. Thought a heat gun may be necessary and likely would ruin it. He agreed with tenting and drying out the transom and drillling holes to drain water if water is concentrated. Regarding the delamenation he said he would just put some silicone on those areas to prevent water entry. He thought it was unlikely the water was entering the upper transom and more likely the motor bracket holes.

As of this date I have everything disconnected from my honda 90 except the steering cable. Then I will lift and suspend the motor with block and tackle from my boat port rafters which I reinforced with some vertical supports. As to what to do with the transom we'll see? I am not sure yet? Your suggestions would be much appreciated.

Tom

[Sea Wolf]

Tom-

You have three very good, if somewhat diverse, opinions and sets of advice to follow up on.

Take a very good look at what you have, investigating the damage throughly. Drill at least a few investigative holes at the bottom interior of the transom to see what you have there in terms of moisture. Probe down into the top of the transom to see how far the damage to the wood and the fiberglass separation goes. Remove damaged material as necessary. Probe around the motor bolts to see how much damage is there. You may have to repair/replace damaged core and fiberglass layers. The advice you have is good as far as it goes. Let us know if you find something different, or something unusual.

Now for the encouragement: You're doing the work yourself, so the labor is free, so there's plenty of room for doing it right as far as the material costs are concerned. Do a totally through job, replacing and reinforcing as necessary. You really can't over do it, making it too strong, but you certainly can leave it too weak, asking for further trouble. Make it both super strong and as waterproof as possible. If you're not sure how to proceed, take pictures, post them here, and describe everything throughly and you'll get lots of advice in return, all for free.

Make an aluminum plate as suggested to bridge the area between the motor bolts, using at least 1/4", preferably 5/16" aluminum plate. (You could also use stainless, since you already have aluminum in the motor and stainless in the bolts, but stainless is harder to work with and not really necessary.)

Don't rush, discover what you've got, and take some time to think about it. It's easier to do it right the first time after some thought, etc.

Good Luck and let us know what you find out!

Joe.

[primative]

Thanks Joe

Much appreciated and useful advice. It reminds me of what a friend used to say when nerves got a little tight on the construction job, that he learned from a horseman out of Montana. In a deep, calm voice, he'd say, "STEEAADDYY"

Thanks to the other previous posters as well. Montana Kev, your link to a prior discussion, Jan. 2011, is right on!

I will report as things develop.

Tom