20 series shifter styles?

[LD5030]

I picked up a 1520 a couple weeks back. This is my first JD outside of a 110 lawn tractor 20 some years back. I was wondering about the shift levers styles. Mine is a late '71 with the non locking shift levers. Looking around on ebay I spied another '71 with an earlier s/n that has the shift levers that have the locking apparatus (red knob on left lever). My question is was that an option or was it likely replaced sometime later. I was thinking that locking style came out with the 30 series. Also was this just a feature to prevent the tractor from being shifted into neutral and being stolen? I'll try and add a pic of the ebay 1520.
Thanks, jim

 

[Anonymous-0]

I have a 1968 1020 Orchard with the same shift lock setup and a friend has one without the shift lock, I`m curious too.

 

[msb]

This was a field conversion initiated by and paid for by Deere ,way back when. Some probably never got changed or were thrown away by the owner or dealer somewhere along the line.Could also have been the tractor ownership or location of the tractor at the time could not have been determined by the selling dealer.I can't remember the exact reason for the upgrade. Probably ,somebody got maimed or killed because of it.

 

[Mike M]

Here's what I remember on those ? Originally they both had straight solid levers. At some point there was a saftey program that put a spring loaded lever on the LH side so when you put it up into park if the tractor gears weren't meshed all the way the spring will pull in up on in. I also think the RH had a lock on it so it stayed put and had to be in the low range only to park. Well alot of owners and myself hated this update and liked them better the way they were and would change them back. I never did like the park setup anyhow as if on a hill it would bind up and you couldn't get it out. Luckily on the backhoe loader you could use the hoe or loader to push you uphill and take off the pressure and get it back in gear.

I like the hand parking brake a lot better they used on the later 40 series. except I never ran one tractor enough to get too used to it and i always seemed to drive off and wonder what that blinking light on the dash was ? DUH !! the hand brake is still on !