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Hi I have a 1966 john deere 1020 the rockshaft housing was broken out by lifting the arms too high anyone know the causes of this? I believe there is a valve stuck or something like that could use some help finding diagrams of hyd. system and other possible causes....Thanks like to hear from you...BW
 

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Welcome to GTT
You can view parts schematics for free at JDparts.com. My guess for reason rockshaft housing broke is because control valves did not return to neutral when RS was fully raised and rockshaft continued to try to raise up. Once new(used) rockshaft housing is installed rockshaft control linkage needs to be adjusted following a JD 1020 service manual. Has stand-by pressure been checked? Stand-by pressure should be 2250 psi.
 

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On the 1020, and lots of other early JD utility tractors, the lift arms were designed to lift all the way and the internal lift arm bottomed out on the housing. Some of the later models (50 and 55 series) had extra linkage to shut off hydraulic pressure before the arm bottomed out. This was done because they enlarged the lift cylinder diameter for more lifting power and they could break the housing because of too much lifting force. If your broke, your hydraulic pump may be adjusted for too high of a pressure as TxJim suggested. There is also a thermal relief valve in the rockshaft housing that could malfunction and Cause breakage if pressure builds too high due to thermal expansion. The last reason that can break the housing is if you have a heavy implement on the hitch and hit a large bump at speed, the implement can bounce up and slam the rockshaft arm up against the housing with enough force to break it. Item 5 is the thermal relief valve.
 

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Thanks for the info

I appreciate you both for the info. parts are about a week away, I will check back when they get here for more help...Thanks a bunch
 

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Ouch

Ouch, that sounds like :gizmo: just for parts.

Sorry to hear of those troubles. I"m not a fan of engineering that builds in a potential break and then relies on relief valves to prevent the issue. It seems like the internal cylinder should bottom out before impinging on the housing. Dunno, maybe I'm not looking at it right.

Treefarmer
 

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I"m not a fan of engineering that builds in a potential break and then relies on relief valves to prevent the issue. It seems like the internal cylinder should bottom out before impinging on the housing. Dunno, maybe I'm not looking at it right.

Treefarmer
I've been around JD utility tractors similar to this 1020 ever since '65 and have seen only one tractor that the rockshaft housing cracked. 21 of those yrs I was employed at JD dealership.
 

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I am afraid I am having a similar issue. I bought this JD 300 about a year ago, it has a model 92 backhoe mounted and had been sitting out in the elements for years. I have done quite a bit of work to get it in working order. I have been using the machine just for the loader and backhoe. The rockshafts have not functioned since I have owned it. I decided to dismount the backhoe in order to mount a bush hog. The lift arms were frozen and the piston was stuck in the bore. I was able to find all of the parts online to overhaul the rockshaft assembly, but I seen the crack as soon as I picked the housing up off the tractor and set it on the bench. I am sure there is not a good way to repair this and a new assembly is an order.
I have heard of people welding cast iron with nickel rods using a preheat, but I've never tried to weld cast iron, suggestions?
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Welding cast iron is tricky. (I am talking about the casting and not the casing for the piston)

There are many compositions of cast iron and different types of welding rods are required (I have used three different rods to date)

If you find someone with the requisite skills and knowledge remember that you also have to allow the piece to cool down.

I used sand to preheat . . . remove casting from the sand and do not allow to cool, weld right away . . . return casting to the sand and allow to cool overnight . . . this relieves the stress inside the piece

If you can but the part I would buy . . . Because it is such a lengthy process I weld cast only if the part is discontinued or if it is not subject to high loads

I am an old-time stick welder so I am sure there may be new techniques that work as well or better

Good luck!
 

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Thank you all for the feedback,
I decided to take TxJim's advice a look for a used housing. I found 1 used online at a place called Eastern Triangle Enterprise. I have purchased it and it should ship today. The part number was R55137, which according to the seller, is a sub number for AT20197.
Welding the crack just sounds like too much trouble, thank you for explaining to process.
I wonder what caused the crack in the first place?
 
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