V-Twin 26HP engine blowing oil at parting line of crankcase

[fairlaniac]

It looks like the V-twin on my Husquvarna is spraying oil. I'll assume by the location and what I see the crankcase gasket has given way? While I pull the bottom off the engine to replace the gasket, what else should I replace while in there? Are there any exploded views with BOM availble?

Thanks,

 

[Bertrrr]

Unless you find something very obvious just install an new gasket and keep right on mowing

 

[bertsmobile1]

It looks like the V-twin on my Husquvarna is spraying oil. I'll assume by the location and what I see the crankcase gasket has given way? While I pull the bottom off the engine to replace the gasket, what else should I replace while in there? Are there any exploded views with BOM availble?

Thanks,

The oil seal as you will damage it removing the sump

 

[TiIngot]

I'm new to this so I hope others don't mind me asking a question. I just do not know why a crankcase gasket would just fail on its own. Crank shaft oil seals failing yes. But, the case gasket is a non-moving, no friction part. Other parts in that area that I have found the source of leaks are an oil filter loose and I have found two oil drain nipples loose too.

With no pressure in the crankcase and no moving parts, are you sure that is the source of your leak?

 

[StarTech]

They do fail. I had engine here in the shop the gasket looked like swiss cheese or expanded steel. Replaced it with the Briggs gasket and it illiterately blew out in two passes on the customer yard and this was with the 27 ft/lbs of torque on the new screws.

It appeared there was two problems. First the gasket was defective. Second the PCV valve appeared to partly at fault. The initial gasket looked like it was made from file folder paper (actually from Briggs) and the last replacement was an aftermarket that actual looked like gasket material.

Now the gasket is only torque to 25ft/lbs and it holding find. Conclusion is that the Briggs gasket was defective. And PCV was replaced just to be double sure the crankcase was venting properly.

 

[Forest#2]

You did not list the engine model number.
If it has the oil pump the gasket replace procedure is little different. You can find some you tube videos about such. Look at more than one.

I make a test fit without the gasket after I get all cleaned good. If the crankshaft end play is within specs, usually .005-.030 without the gasket I just use Yamaha Bond 4 and no gasket. Most OEM gaskets are .015 thick. I wait at least 24 hours before adding oil so as to let the Yamaha Bond 4 cure good.
If it needs a gasket I use Yamaha bond 4 on each side of the gasket. (just a very light smear when using the Yamaha Bond 4)
I use a wire brush on a battery operated drill and the crankcase stuffed full of hand towels to keep the internal block clean when using the wire brush to clean the gasket surfaces and then wipe the aluminum mating surfaces good with lacquer thinner or acetone.
Be careful when attempting to remove the 3 oil pump cover screws. Tap on them first then use a good fitting 5/16 6 point socket. If the socket slips just once and you round them off they can be a pain.

 

[Rivets]

Before you pull the engine I have a question. Is the oil leaking in the area under the cylinder heads. If so you may have one or both head gaskets bad, blowing oil out. Just something to check before jumping to conclusions and spending $$$$ you don’t have to.

 

[Forest#2]

As Rivets says it should not be spraying oil out the crankcase gasket unless the breather has failed and causing the crankcase to pressurize. (or maybe bad head gasket sending excess pressure to the crankcase)
Spraying oil indicates a pressure is being applied.
Normally when the sump crankcase gasket fails it just leaks oil, no spraying.
If you cannot tell for sure where the oil leak is coming from you can get a oil leak dye kit.

 

[bertsmobile1]

I'm new to this so I hope others don't mind me asking a question. I just do not know why a crankcase gasket would just fail on its own. Crank shaft oil seals failing yes. But, the case gasket is a non-moving, no friction part. Other parts in that area that I have found the source of leaks are an oil filter loose and I have found two oil drain nipples loose too.

With no pressure in the crankcase and no moving parts, are you sure that is the source of your leak?

The purpose of a gasket is to allow 2 parts that are subject to small movements to maintain a pressure tight seal
In this case the block is substantially hotter than the sump so it espands more than the sump does although the sump eventually catches up
As such the two part move against each other so a flexiable material is needed to bridge the gap between them
Now the crankcase is subjected to pressure pulses which is how an impulse pump works so a weakened gasket, often is a spot where the machining is not as good as it could be or the clamping force holding the gasket in place is not sufficient allows a sectio of the gasket to fail .