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420 Front Seal on Onan

859 Views 7 Replies 5 Participants Last post by  spc450
I had the front seal on the engine replaced when recommended by the JD service rep. Then after 2 hours of use it is leaking again. Took it back to the dealer and they are replacing it for free but they are trying to tell me it is the crankcase ventilation that is the problem. Has anyone ever come across this? If the pressure was getting that high, shouldn't I be able to notice it when I pull the dipstick?

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I found it interesting that no one has commented on this. I have my 420 apart in the garage because of an oil leak and it was leaking at the seal under the front PTO. I did have some oil in the air filter and I suspect high crank case pressure as well. this is an engine I rebuilt about 50 hours ago. It runs great otherwise
I have the parts to fix the leak and I bought the parts to rebuild the breather and a new flapper valve.
My question is will this fix the problem? How else can you fix high crank case pressure?
Yeah John I was wondering why no one responded too. My concern is if the dealer really thinks it is the ventilation then why aren't they offering to fix it? It's not like I have ever told them no. I spent more on maintainence this year than it is worth. But still love the old girl.
I got a chance to finish pulling mine apart and now I believe it was simply a bad or damaged front seal. When I looked at it there were 3 small nicks in the rubber edge and after removing it from the front cover it was hard and the edge broke off. The flapper had some crud under it not letting it work properly so I am in the process of putting it back together as time and the heat allows
I just spoke to my dealer/mechanic last week about oil in the air cleaner. He thinks, given the age of my machine, that it is the result of excess crank case pressure due to blow by. He said that people often route a hose from the PCV tube down to under the frame of the tractor to keep oil out of the air cleaner (you have to seal the hole). I'll probably do that as the engine runs fine otherwise.
for quite some time i have had an issue with the way my tractor starts. i almost always keep it on a trickle charge of 2 amps. but when i turn the key to start it i usually get a few clicks of the solenoid,i believe, then it will engage the starter and run fine. the other day i saw on line a starter relay kit

John Deere Starting Improvement Relay Kit - AM107421
anyone have any thoughts on installing this ?
it talks about a voltage drop between the battery and solenoid on starting that it will remedy .
thanks steve
From what you describe, the starter improvement kit should help. It's not hard to install.
thanks cliff i decided to stick my neck out and buy the $35 kit and it did the trick. starts right up now. no more clicking of the solenoid.
took about 10 minutes to install.
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