Westerbeke W52 - oil leak from back of engine

[kevins]

I Have a rebuilt Westerbeke W52 with about 800 hours on it and it works well except has developed a small oil leak at the back of the engine.
This leak has some interesting features.

- The engine leaks about 1 teaspoon of oil (maybe less) when it leaks.
- It only leaks when I shut off the engine, not while it's running. (it leaks every time I shut of the engine no matter how long it has been running)
- The leak is coming from the between the backing plate and where the transmission connects, or possible where the backing plate connects to the block.

Has anyone experienced such a thing?

thanks
Kevin

[model 10]

There is probably a groove worn in the crank surface. With oil pressure, the fairly new seal is/ has been doing OK. Now as the seal is getting older and more stiff, it does not seal as well without pressure on it. The little bit of oil you are getting is probably just that bit in the seal housing behind the lip.

[zboss]

Rear seal. Just had my replaced on my 46...not a cheap part and the way westerbeke builds them, not an oil seal part you can buy anywhere. Took me 12 weeks to get one in from Japan since WB did not have any available in the USA.

Unless you really really really want to replace it, just leave it leak oil like the rest of us. On my 46 you need to replace all the oil seals if you are replacing one, since you have to take off the oil pan to get to the rear oil seal. While you are in there, you might as well replace the damper plate as well.

[kevins]

Ok...i will wait.
I just replaced that thing when we rebuilt the engine. I have another one. But i suppose it is quite the job to do.
I suppose it will just get worse and worse over time and at some point I will have to replace it...is that what you think will happen?

[model 10]

One way to look at it is this, you got 800 hours from the last new seal. The best you will get from another new seal is probably no more than another 800 hours. So, put off the start of the next 800 hours as long as possible. You will always have the choice of a new or repaired crankshaft during your next ovhl.

[zboss]

I would not worry about the crankshaft. When we took ours apart the shaft was fine. It will take a long time to wear out a new seal. Did you get a proper alignment when you put the new seal in?


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[kevins]

I will watch it, I also have a leak on the time cover in the front which I will fix in the next couple weeks and then maybe the leak in the back won't look so bad.

I believe the crankshaft was aligned correctly, it was spinning quite freely when it was all bolted together. I am no mechanic, but the guy who put it together with me is...he is my dad.

I guess I will just add that to the List of things I need to watch and carry on for a while.

Thanks for your help.

[SeaSon]

Well my lehman had a rear main seal leak heavier than yours - a few tablespoons per day on an 8 hour run - and I had no plans to rebuild, just to replace oilzorbs as needed. On a 'what can it hurt basis', At my next oil change I added oil leak stop stuff from the auto parts store as my research indicates it won't clog passages, just rejuvinates the seals. 2 bottles for my 2.5 gallons of oil. After a week of running, leak stopped! 4000 total hours on engine. 80 hours since adding. I would have been happy if it just slowed it, but it stopped!

I'm sure the arm chair mechanics here will say 'oh dear good, what has he done', but these lehmans are basically just tractor engines. Fyi, The stuff came out of the bottle like super heavy oil with very long molecules.

[Scrimshaw4]

You might want to check that all of the bolts were torqued properly on the engine. Leak stop addatives work great and won't gum up the engine. An oil cjange 25 hrs after adding, presuming the leak has stiopped, will clear out most of the residual addative.

[zboss]

The rear seal on the westerbeke's is a rubber gasket with a spring inside that pulls the gasket into place. No amount of leak stop is going to help that gasket do its job. If the leak is in the pan or the front seal, those are made of basically wax paper and it may help.

FYI - I got a complete gasket set (every gasket minus the rear seal) from Alibaba direct from China for about $125 vs. the almost $800 WB wanted. I did this by finding my block type, which for mine is a mitsubishi engine and looking up the seal kit.

[kevins]

Ok...I have the gasket from a Ford Ranger 2200 1981-3. I would be interested in knowing which gasket set you got.

Can I replace the rear gasket by dropping the pan a bit and putting in a new one? The bit of challenge is supporting the motor while I take the rear housing off, for the motor mounts are connected to the housing. I believe I have the gasket from the ford ranger which I can put in if it does not require completing removing the pan. Then the job becomes much bigger.

any thoughts

[zboss]

Originally Posted by kevins

Ok...I have the gasket from a Ford Ranger 2200 1981-3. I would be interested in knowing which gasket set you got.

Can I replace the rear gasket by dropping the pan a bit and putting in a new one? The bit of challenge is supporting the motor while I take the rear housing off, for the motor mounts are connected to the housing. I believe I have the gasket from the ford ranger which I can put in if it does not require completing removing the pan. Then the job becomes much bigger.

any thoughts

The pan really needs to be removed... its very light weight and its expensive to replace. We were able to do it with the engine in place: we loosened the mounting (actually just unscrewed them from the mounting frame so we did not mess up the alignment) and then used a come-along to lift the rear of the engine using the lifting bracket. We were then able to unbolt the shaft, slide the shaft back, remove the transmission, the bell housing, etc... and the oil pan, and everything else needed, then put the new one on. It would have been very difficult to do it with the pan already on... and since you are breaking the oil pan seal anyhow, you might as well replace it.

However, I do not know what your access looks like and I'm not really sure how different the 52 is from the 46 so your milage will vary.

[kevins]

great idea on supporting the engine while replacing the gasket.

nothing to lose trying to oil stop leak stuff.

thanks

kevin

[zboss]

Originally Posted by kevins

great idea on supporting the engine while replacing the gasket.

nothing to lose trying to oil stop leak stuff.

thanks

kevin

BTW - When I say "might as well replace it" I am referring to the oil pan seals, not the pan!

Another advantage of getting the oil pan off is being able to clean sludge out of it and getting any metal shavings that happen to be left over from the rebuild run-in that normally come out with an oil-change.