Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor

Kris

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
I've had this lawnmower for a number of years now and it has served me well. The mower has developed an oil leak and would like to know how to diagnose and repair. Any help with be appreciated.

Regards,

Kris
 

reynoldston

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
First thing is clean it real well, pressure washer or car wash. Run mower and figure out where it is leaking from. One of the most common places for a oil leak is the lower crankshaft seal. If this is the case remove pulleys, remove old seal, I install a small selftaping screw in old seal and pull old seal out, tap in new seal.
 

JDgreen

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
I've had this lawnmower for a number of years now and it has served me well. The mower has developed an oil leak and would like to know how to diagnose and repair. Any help with be appreciated.

Regards,

Kris

Specifics, specifics, please. Is the ENGINE leaking or the MOWER DECK? And the advice to clean it well to locate the leak is a great idea, hopefully you will be able to see where the leak is coming from then.
 

Briana

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
Hey there - WELCOME to LMF!

I moved your thread to the Craftsman Forum. :smile:
 

reynoldston

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
Specifics, specifics, please. Is the ENGINE leaking or the MOWER DECK? And the advice to clean it well to locate the leak is a great idea, hopefully you will be able to see where the leak is coming from then.

Being a 12 hp Craftsman I sure can't understand a oil leak on the mower deck. As far as that gos I would almost bet it doesn't even have grease fittings on the bearing flanges.
 

JDgreen

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
Being a 12 hp Craftsman I sure can't understand a oil leak on the mower deck. As far as that gos I would almost bet it doesn't even have grease fittings on the bearing flanges.

And I would bet OP wouldn't know what a crankshaft seal was if it jumped out and bit them on their nose.
 

ILENGINE

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
I would almost bet is is the engine sump gasket that is leaking. or the seal around the dipstick tube if it has one.
 

reynoldston

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
And I would bet OP wouldn't know what a crankshaft seal was if it jumped out and bit them on their nose.

This I well understand but just trying. Just because it is a lawnmower everybody knows what they are doing didn't you know this. I have always said if you don't know what you are doing take it to someone that does it can be cheaper. I do a lot of repairs and see where someone made a mess and then brings it to me to fix right. Also sometimes I all just refuse the job if it is too messed up. Seeing I have a lot of retired time I sure have fun (just trying) on this forum. Also someones broken or leaking mower is not my problem it is their problem. When I give my opinion it is up to them if they want it or not or who they want it from I do not care. I also know that a lot of people on this forum know a lot more about mowers then I do, but I know the repair business part of it seeing I have done it all my life and no two repair jobs are alike.
 

Kris

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
First thing is clean it real well, pressure washer or car wash. Run mower and figure out where it is leaking from. One of the most common places for a oil leak is the lower crankshaft seal. If this is the case remove pulleys, remove old seal, I install a small selftaping screw in old seal and pull old seal out, tap in new seal.
------------------------------------------------------------------------------------------------------------------------Thanks Reynoldston,
I will give it a good cleaning next time I'm up at my cottage. I managed to download the manual from the internet which would be a huge help. The leak appears to be down below the air filter side of the engine but will determine that next time. I have replaced the retainer springs a number of years ago and have some experiencing rebuilding a 70HP Johnson motor for my boat with the help of a mechanic friend of mine.
Also, there is occasional smoking while the engine is running.
 
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sfestus

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  • / Craftsman 12 HP 38 Inch Mower Deck 5 Speed Lawn Tractor
Hi...If it smokes on start up...It's worn rings, but if it starts to smoke after running for a few minutes then it's a blown head gasket causing pressure to build up in the crankcase, and forcing it through the oil breather tube into the carb. Check to see if the carb has any oily residue in it. Also what grde of oil are you using. Should use a sae 30 weight, not any of the lighter multigrade oils. Since it's a 12hp 38in tractor it must be close to 20 years old now and another thing to check the dipstick if the oil smells like fuel. These mowers have a tendency to have the fuel float getting stuck open, and feul going through the carb. into the oil breather tube into the crankcase...leading to thinning oil, smoking, and leaking....good luck
 
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