I want to know year of JD 318 mower by serial number.

take the details to a JD service center and they will have all the answers

take all the details to a JD service center and they will help you with all that information

Call a JD dealer or go online to JD and ask the service guys.

1961-1000
1962-19804
1963-32,000

JD 400 Garden tractors were made from 1975 - 1983.
Serial Numbers
1975: 30001
1976: 55001
1977: 70001
1978: 80001
1979: 95001
1980: 120001
1981: 155001
1982: 190001

Go to this site and you may be able to track it down.
John Deere 400 attachments
http://www.tractordata.com/lawn-tractors/000/0/4/41-john-deere-400-attachments.html

Be sure to read this discussion on serial numbers.

Tractor serial numbers

"Find the REAL serial number
There are usually a lot of different numbers on a tractor. The engine, front axle, and cab may all have their own serial numbers. Various components may have parts or casting numbers. Make sure you have actually found the tractor serial number, and not one of these other numbers."

Call your nearest JD parts agent or JD direct. If you want a free owners manual go to deere.com there is one for 60,90 and 125 loaders on download.

What possible difference can it make? You have not mentioned a make or model for the mower or tractor nor have you mentioned the make and model of the engine ... though you have listed a big number. (There is such a thing as a tractor mower ...) I find no meaning in the number.

Please state what you are trying to do, need parts? Trying to establish year to negeotiate a price?

Best thing I can tell you to do is determine in your own mind whether this number is for a machine or the power supply. Contact the appropriate local source - they may be able to tell you, based on the serial number or model, an approximate range of years it may have been manufactured.

If it is parts you need, just see the local repair shop.

Thanks for your interesting question @ FixYa.com

Your tractor has a hydrostatic transmission, I'm not sure about the lock on the dash board down next to the key, but most hydro's, you just slam them into gear and go, and it will go back and forth till you get tired of going back and forth. I love the thing. Check it out. Hope this helps.

this forum is for the kids toy