need help with a 40 crawler

[colorado]

my dad got a JD crawler, we think its a 40 but not sure, its a 5 rollers, no water pump. data plate is gone. is there another way to find out what it is. i need a ring gear P/N M1631T. some people say that i should have a 7/32 pinion/ring gear but i got a 9/41. is that legit. thanks

[original possum]

Are you sure it isn't 8/41?

[colorado]

count it twice and it gave me a 9/41