jd 4020 synchro won't shift Into park

[sven556]

This is a fairly new to me tractor. A 1965 John Deere 4020 diesel synchro range tractor. When I test drove it and drove it the 24 miles home I did not have any trouble shifting in any gear or back into park (8th gear was a bit hard to find). Now after having it home a few weeks and working on other small issues ie dash lights, gauges, etc. Yesterday I started it up and turned it around in the driveway and it would no longer shift back in to park. I drove it again today maybe 50 yds each way and it still won't shift into park. I'll have to check tomorrow but I think I was in the 2-5 gear range and it won't move any higher with the gear shift all the way on the left side (neutral?). 2-5 and reverse all work. I did not try to go to the 4-7 or 6-8 shift patterns. I'm planning on adjusting the shift linkages by the manual but if anyone has any known issues I should be aware of or other suggestions please let me know. Thanks.

 

[Tx Jim]

My guess is wear/slack between the 2 shifting quadrants(items 10 & 16). Be sure to check for wear in bushings & wear on latch(item 5).

 

[tim s]

My thought is the the spring on the shift cam is broken..down on the bottom shaft.

 

[sven556]

Thanks for the suggestions. I'll look through the shifter and see how much wear/slop there is. Might replace bushings while I am there.

Is there any way to check the spring on the bottom shaft?

 

[sven556]

Is there any way to check the spring without tearing down the transmission? ]l urethane

 

[Tx Jim]

I don't know the answer to Tim S reply but I attempted to contact him via phone & email for clarification but I haven't received a reply from him. I hope he's just very busy & not ill.

If he's referring to the shifter cam detent spring(item 16) that would be easy to change by removing a hex plug. But if the other spring(item 18) then that would be a lot more complicated.