[aharlan001]

Greetings! Back again with another 345 fire... this time the fire did not damage the tractor much and it still runs great. Now for the source of the fire which I believe to be an oil leak somewhere, it has been intermittently smoking for a few months. This is a 900 hour 345 with the 20hp.

Before you say it is a valve cover gasket (which is what I was thinking too initially) not so fast. I just replaced the gaskets with the flat type and metal covers last year. It could be the valve cover but there was a ton of dark brown ?oil? leakage from much higher up coming from the front above the carb and coolant hose, on the right side and left above each head... trouble is I'm not sure if this is just from a mixture of water (from putting the fire out) and 20 years of grime or a leak??? I pulled the radiator/air intake/flywheel and this is what I see. (I did use penetrating oil on the flywheel so that could explain the oil on the crank shaft seal)

So, do I do the breather cover seal, breather cover, and Crank shaft seal.... or not? I'll probably add a little RTV to each side of my valve covers for good measure but I'm really not convinced they have anything to do with this...

Not sure if this is related but whenever I change the oil it looks a little suspicious ?milky? and the coolant is always a little less clear than it ought to be. Probably needs head gaskets but I've chosen to keep an eye on it and just change the coolant and oil more frequently in the short term.

 

[Trentofdestiny]

Is that stator okay or did it get fire damage? Definitely needs cleaned but brake cleaner might damage the epoxy that holds the coils. I'd recommend alcohol based cleaner. I'm not sure if you need a crank seal but couldn't hurt to put it in.


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[denverguy]

Crank seal looks damaged in your pictures and would be my bet as your issue. I'd replace the breather gasket as well.

I'd bet the coolant in your oil is a wearing water pump. It's driven off the cam and when the seal wears out it leaks into your oil.

 

[aharlan001]

Is that stator okay or did it get fire damage? Definitely needs cleaned but brake cleaner might damage the epoxy that holds the coils. I'd recommend alcohol based cleaner. I'm not sure if you need a crank seal but couldn't hurt to put it in.


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The stator is okay from what I can tell, no fire damage in this area at all. It started and ran after the fire no problem except for the leak? and smoke. I already cleaned it with brake cleaner, oops, the epoxy on the coils looks ok. Leaning towards doing the seals just in case. I should have posted the after cleaning photos with the initial post as it is hard to see anything in that dirty mess. See attached after cleaning photos.

 

[aharlan001]

Crank seal looks damaged in your pictures and would be my bet as your issue. I'd replace the breather gasket as well.

I'd be the coolant in your oil is a wearing water pump. It's driven off the cam and when the seal wears out it leaks into your oil.

I agree with replacing both. So you are thinking that the pooling on top is more than just water plus 20 years of grime? After cleaning the crank seal it looks okay. Good to know about the oil pump being the likely leak. Any way to know this for sure? From what I'm seeing online I have to pull the engine to do the pump... no fun... also of note there is copious aftermarket rtv both red and black on the water pump and water pump cover seam... any thoughts on the relevance/implications of this?

I posted the after cleaning photos above.

 

[denverguy]

You do have to pull, or at least lift, the engine. Can only speculate regarding the RTV - I wouldn't expect two water pumps in 900 hours but who knows what they did.

How to know for sure? You can pressure test it. Not really sure the best way to do so given you have it partly torn down.

 

[denverguy]

I just looked at your pictures again, missed the magnet stuck to the stator. Are you replacing the flywheel or gluing the magnet back? Heat can damage magnets, something to consider if you are planning to glue back.

I do think that you have a top-end oil leak - either the seal or the breather. Yes, the seal doesn't look damaged in your subsequent pics but seals don't need to look bad to leak. And given that valve covers aren't under pressure, they leak down not up so I wouldn't have said valve covers are your source.

Back to the source of your fire - do you have the upgraded fuel pump and a drain hose attached? Seems you would need one heck of an oil leak for it to be the source of your fire.

 

[aharlan001]

I just looked at your pictures again, missed the magnet stuck to the stator. Are you replacing the flywheel or gluing the magnet back? Heat can damage magnets, something to consider if you are planning to glue back.

I do think that you have a top-end oil leak - either the seal or the breather. Yes, the seal doesn't look damaged in your subsequent pics but seals don't need to look bad to leak. And given that valve covers aren't under pressure, they leak down not up so I wouldn't have said valve covers are your source.

Back to the source of your fire - do you have the upgraded fuel pump and a drain hose attached? Seems you would need one heck of an oil leak for it to be the source of your fire.

Wow good eye! Yes that magnet will need reattached. Didn't even realize that! I have an old parts rig (older 18hp 345) that was also fire damaged and I gave up on due to smoking issues after fire repairs (cracked head?). Very little heat reached this area of the tractor on either rig from what I can tell. Should I use the older 345 flywheel or glue this one back?

Also regarding the fire source I think I have the upgraded pump but I'm not sure. I definitely have a hose running from that area (not sure from what exactly) down to the frame. I think my fuel pump is aftermarket I think I remember it being a brass color... I'll post a picture later tonight when I get off work. Thanks!

 

[denverguy]

If it were me, I'd swap the flywheels since you have a spare. Clearly, the fire was hot enough to release whatever adhesive was used to secure the magnet.

 

[aharlan001]

If it were me, I'd swap the flywheels since you have a spare. Clearly, the fire was hot enough to release whatever adhesive was used to secure the magnet.

Ok, I was thinking it came off from the removal process but I guess probably not.

 

[javjacob]

I will also mention the fuel pump. The original fuel pumps were faulty and were known to cause fires. The new ones are updated with a drain hose that goes out the bottom of the tractor. If it doesn't have the drain hose you need to throw that one in the trash and buy a new one which will have the drain hose.

 

[aharlan001]

I do have the updated fuel pump but there is no hose attached to the outlet on the bottom! Perhaps this lead to the fire? Also both fuel pump bolts were 1/2-3/4 turn away from snug.

I will also mention the fuel pump. The original fuel pumps were faulty and were known to cause fires. The new ones are updated with a drain hose that goes out the bottom of the tractor. If it doesn't have the drain hose you need to throw that one in the trash and buy a new one which will have the drain hose.

I do have the updated fuel pump but there is no hose attached to the outlet on the bottom! Perhaps this lead to the fire? Also both fuel pump bolts were 1/2-3/4 turn away from snug.

 

[aharlan001]

So I just got the output shaft gasket in this evening and I figured I would knock that out real quick. Trouble is after taking out the old gasket I see something ?damaged? There are metal bits from a thin metal collar around the output shaft where it comes through the cover. I can remove the loose ones but what is this and should I be concerned? From looking at a parts diagram it looks like it may be the edge of the plane bearing? Not sure... please advise. I can get clearer pictures later if it matters. I went ahead and looked at this same area on my parts 345 with the 18hp motor, I see no such part there damaged or undamaged.

 

[aharlan001]

So I just got the output shaft gasket in this evening and I figured I would knock that out real quick. Trouble is after taking out the old gasket I see something ?damaged? There are metal bits from a thin metal collar around the output shaft where it comes through the cover. I can remove the loose ones but what is this and should I be concerned? From looking at a parts diagram it looks like it may be the edge of the plane bearing? Not sure... please advise. I can get clearer pictures later if it matters. I went ahead and looked at this same area on my parts 345 with the 18hp motor, I see no such part there damaged or undamaged. View attachment 2551841 View attachment 2551842 View attachment 2551843

 

[denverguy]

Looks like the plain bearing is damaged. It's a cheap part but you have to tear down the engine to get to it.

And, yes, it should be replaced.

 

[aharlan001]

Looks like the plain bearing is damaged. It's a cheap part but you have to tear down the engine to get to it.

And, yes, it should be replaced.

Should be or must be? If I get the little bits what is going to happen if I just let it be? Does not seem like that extra lip has a purpose. Can I at least get another 6 months out of this thing then maybe teardown this winter? I don't know if I have it in me to tear this engine apart.

 

[ST1100A]

If that plain bearing is bad, it can let the crank move a bit and cause a new seal to leak. The seal did look like it was popped out a bit further than normal. The main crank seal is usually down in a little bit further than the one in the picture. I've seen them blow out already and had to be pushed back in.
Another thing to check is the breather cover plate with the 4 bolts in between the cylinders. They were known for leaking. That is a steel plate on an aluminum engine block, and they could warp and blow out the gasket under the cover. Some of the new kits had an aluminum cover so they didn't warp like the steel cover did.
There was an 'Update' for the cover, a new cover and gasket in the kit. If the cover was the cause of the oil leak, the oil will get all over the stator and main seal, besides inside the flywheel and drip down the engine all over the place, especially between the cylinders, down behind the carburetor and governor linkage/throttle linkage area.

 

[aharlan001]

Should be or must be? If I get the little bits what is going to happen if I just let it be? Does not seem like that extra lip has a purpose. Can I at least get another 6 months out of this thing then maybe teardown this winter?

If that plain bearing is bad, it can let the crank move a bit and cause a new seal to leak. The seal did look like it was popped out a bit further than normal. The main crank seal is usually down in a little bit further than the one in the picture. I've seen them blow out already and had to be pushed back in.
Another thing to check is the breather cover plate with the 4 bolts in between the cylinders. They were known for leaking. That is a steel plate on an aluminum engine block, and they could warp and blow out the gasket under the cover. Some of the new kits had an aluminum cover so they didn't warp like the steel cover did.
There was an 'Update' for the cover, a new cover and gasket in the kit. If the cover was the cause of the oil leak, the oil will get all over the stator and main seal, besides inside the flywheel and drip down the engine all over the place, especially between the cylinders, down behind the carburetor and governor linkage/throttle linkage area.

Ok, there is no perceptible motion of the crank but I suppose there probably is some excessive wear there. Not sure how to explain why the bearing looks this way if this is not the case. What will happen if I let this go?

 

[sthpawil]

I agree that you should definitely replace the breather cover and gasket with the updated kit from John Deere. The new breather cover is much thicker and more robust than the original.

The engine on a X340 that I recently picked up was soaked all over with oil, and underneath the flywheel was an oily/dirty/grass packed disaster.

After a thorough cleaning, I installed the new breather cover kit, new O-ring behind the oil cooler (the thing that the oil filter screws onto), new O-rings on oil fill tube and oil drain tube, and new rocker cover gaskets (after adjusting valve clearance). After putting a few hours on the engine, there isn't a drop of oil in sight.

One thing to note: There was a dirty old paper filter inside the breather of the X340. The instructions with the new breather cover kit said to remove and discard this filter, and to not replace it. I followed those instructions.

 

[Frogmore]

Definitely replace the cover with the new kit and remove the filter. It was causing excessive oil in the carb on my X534.