4020 3pt hitch problem

[1GH]

Hello all,I'm new here. I have a 1964 4020 with a 3pt hitch. A while back i replaced the seals on the draft control shaft. When I refilled it with oil it wouldnt work, and hasn't since. I have learned that the linkage at the top of the load control arm has somehow come away from the cam on the rock shaft. My problem is, even with the JD service manual, I cant tell for sure what is supposed to line up with what. The pictures or drawings in the manual are all from the same angle. I think i should be able to figure it out if i pull the control valve assembly off of the rock shaft housing but i'm not sure. Anyone here have experience with this specific situation?

Later Geo.

 

[beenthere]

:welcome: to TBN

Hang tight, as several experienced members will be along to help you out.

 

[Tx Jim]

Welcome to TBN
Do you have L/D control lever in "D"? Have you tried adjusting stud(key 3)? When changing L/D seals cam(key 8) rarely gets out of position but it has occurred. Yes cam can be replaced in correct position by R&R of RS control housing.Cam needs to be in front of link(key 14) 2nd photo. It's also possible spring(key 23) has failed or became detached.

 

[1GH]

Thanks for the quick reply Tx Jim. I'm at work for a couple weeks so I'm going by memory here, the L/D lever was at the bottom position(I think thats D) and it was stuck there. Not knowing where it was supposed to be and already grasping at straws I got it moved. Now it wont go back down. It feels like its caught behind or below the spring you mentioned. Can this be manipulated somehow through the oil filler hole if the extension and cap are removed?

 

[Tx Jim]

Thanks for the quick reply Tx Jim. ICan this be manipulated somehow through the oil filler hole if the extension and cap are removed?

You're welcome. Sorry but I think you'll need to remove RS valve housing to resolve the 3 pt problem. 1st I'll suggest to acquire a 5000# gauge and check stand-by pressure. If stand-by pressure isn't above 1700 psi the priority valve would be blocking pressure oil to 3 pt. Stand-by pressure should be 2250 psi. Does steering operate correctly?

 

[1GH]

Power steering works great. Probably wouldnt hurt to check the pressure but I dont believe that to be the problem. Where would I connect the gauge if i can borrow one? As far as removing the valve control housing, is anything going to fly apart when I lift it off? How about putting it back on, will I need a third hand? Lol. A couple days before i came back to work, I started to remove the valve control thing and got cut short when a thunderstorm came up unexpectedly.(my shop is the open-air variety) Is it normal to lose about a gallon of hydraulic fluid out of the pressure line for the 3pt. piston? Once I got the line loosened enough to turn it up I could see it didnt come from the piston end of the line but from the fitting on the valve body.

Later Geo

 

[Tx Jim]

A 5000# gauge can be purchased here for about $15. IIRC if 3 pt is lowered not much oil will be lost. I don't remember valve housing being very difficult to replace but it's been a long time('87) since I served as a JD dealer service manager. Getting cam in correct relationship with linkage is the most difficult part

 

[1GH]

I guess thats where I'll need to grow that third hand i mentioned.

Later Geo

 

[tysmobiletractor]

I have a neighbor who asked if I could replace the seals in his 4020 lower shaft. After reading this I'm not sure I want to deal with possible troubles that could result. How often do these 3pt issues result from changing the seals?
Thanks.

 

[Tx Jim]

I have a neighbor who asked if I could replace the seals in his 4020 lower shaft. After reading this I'm not sure I want to deal with possible troubles that could result. How often do these 3pt issues result from changing the seals?
Thanks.

Over the yrs since 1964 many 1000's of L/D seals have been changed on 3020/4020's with ZERO problems. Always put L/D lever in "D" before removing L/D shaft and oil shaft with trans oil before reinstalling shaft. If I was attempting to R&R bushings I'd recommend using Boling Machine shop bushings that have a groove for a seal machined in bushings. My experience is coming from being employed at a JD dealership from '66-'87 with the last 13+ yrs serving as a service manager.
Good luck,Jim