Yanmar SVE 8 Oil Leak

[Greenman]

Okay, I got my engine out today, and unfortunately it looks like the leak is not something simple like an oil pan gasket. I suspect it's the rear main.

Considering this is a 35 year old motor, what are the odds of an reasonably inexpensive repair?

It'a a 1975 Yanmar SVE-8

 

[garyc]

I think removing engine is the hard part. changing seal or gaskets should be a lot easier

 

[Bill Roosa]

Can't tell what is leaking

I can see that the crank to prop shaft connector is covered with oil but can't see where the shaft enters the engine. The connector is not where the leak is coming from BTW it just has a lot of oil in/on it.
changing crankshaft seals is pretty easy even with the engine in the boat provided you can get the propshaft out of the way enough to allow the old seal to be removed and the new one slipped over the shaft.
The seal is held in place by the oil pan and block and just slides along the shaft for removal/instlation. Just drop the oil pan, SLIGHTLY loosen the crank journal bolts to drop the crank a smidgen then pull the seal. I've done it without loosening the crank but getting the new one on back in is much harder.
this all assumes that the rear main is in fact the offending part of course.

 

[Ed Schenck]

If parts are available it should not be difficult. If you are satisfied with the engine's ability to move your boat then maybe a complete rebuild? Or if it was running well and the compression is good then definitely a rear bearing and seal.

 

[Bill Roosa]

oil leak

For the sake of compleatness:
If the rear main is leaking it can be two different modes, shaft to seal and seal to pan/block. The shaft to seal requries a seal replacement, the seal to pan just need a coating of gasket sealer. You have the engine out so determining exactly which mode is impossable unless you can run the engine somehow at the angle it is in the boat.
It could be that the engine oil level was maintained too high or the angle that the engine was installed in was too steep. No amount of seal replacement will fix either of those issues BTW

 

[Greenman]

I have the engine out and am taking it to a local Yanmar repair shop. I might as well get the engine tuned up while it's out assuming the compression etc. is still good.

 

[Greenman]

Unfortunately the mechanics discovered the crankshaft is corroded badly and have had no luck finding a replacement. Now I am going over options, a new inboard is out of the question (7K +) and I only paid 7K for the entire boat.

I will have to find a used motor or for now hang an outboard on a sliding mount.

At least I have a few months before launch to figure it out.

 

[Rick D]

Metal Spraying?

Once upon a time, construction yards used to metal spray cranks and re-grind them. Don't know if they do that anymore. but it may be worth a check to see if they do and if it's an option. Good luck & happy new year!

 

[kloudie1]

I agree with Rick, if the problem really is a corroded crank under the seal area, it can be "plasma sprayed" and reground to std. size. Another option might be a "speedi sleeve" .. a thin metal sleeve that slips over the corroded area so that the seal lip runs on the little stainless sleeve.
http://www.vsm.skf.com/en-US/HeavyDuty/KitsAndTools/SpeediSleeve.aspx. a much cheaper solution, but both probably require that the crank be removed from the block, although there may be a way to fit a sleeve without removing the crank. A GOOD machine shop will be conversant in both these techniques.. Best of luck to ya..

 

[Greenman]

Thats good info, thanks very much. I will be making some calls.

Happy New Years.

 

[bsavulis]

Plasma spray

I'm not sure where you are located, but I can certianly direct you to shops in CT that do the process. We use it quite a bit in our work. I have a 1975 H27 with a SB8, it is not all that rusty. From the pictures you provided it appears that the your motor has been wet.... alot. Is there another underlying issue? Stuffing box? Just a thought!