John Deere 1840 Question

[Erik M]

I picked up a 1981 JD 1840 row crop (same as 2440) last fall and was curious about the speeds. JD made this tractor in 8/4 and 16/8 speeds and if you look at the tractor it has 8/4 speeds per shift levers, but it also has the Hi-Lo selector. Is this how JD makes a 16/8, as the Hi-Lo selector is a half gear plus or minus?

I am not a tractor guy but have a 650' drive and needed something to move snow. Seems to work well, really enjoy this machine.

 

[buickanddeere]

Figured you were in Canada by the model number. I have the model down, a 1640.