3-Point Hitch 4300 HST 3PT slow / barely working

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Sorry it is dfkrug.

 

[arkvet]

Stiffness could be bits of screen jamming this spool valve itself (tearing O-rings), or where the lever goes across the top of the axle housing it could be binding or getting stiff. Is or has the tractor ever been used in salty conditions? Depending how when where the tractor is used, mud, dirt and crud can build up in the area under the seat where the shaft goes across. I am NOT at my computer right now but search for 4300 rebuild by defrug ( not a hundred percent if that's the right spelling) ? And he has lots of great pictures of linkage and control valve taken apart.

I'm in Arkansas which is south enough to never see salt. It's used in mud all the time but I do keep it pretty clean. Your first sentence answers my question I think. The stiffness has 100% paralleled the reduction in function of the 3pt. If it had become stiff and then all the sudden (at a later time) I started seeing problems with the lift then it might be a "crud" problem . I'll still of course give it a good inspection and thorough cleaning but hopefully I can find that screen and replace some o-rings and be ready to go. Fingers crossed!

I have scavenged that rebuild thread multiple times for other issues with my 4300. That thing is gold for any 4000 series owner!

 

[dfkrug]

To me the filter seemed redundant... and how ironic that the stupid filter caused a
problem that the filter was intended to prevent... Just plain stupid.

So as it stands I am going to break it down and pop out the mesh screen that is broken and toss it in the trash.
I'll then remove the control valve and see if I can visually find the problem before spending $500 on a new one.

One technical question remaining: The Rockshaft lever is extremely difficult to move up and down. Can this be
tied directly to the problem with the valve or do I likely have a concurrent problem with the "tension disc" that
I've seen mentioned in other threads.

Just saw this thread.

Both of my rebuilt 4300s are working fine, with no inline filters between the AUX valve and the 3-pt cyl valve.

Both of my units were early models with the small rough mesh filter which looks like a fitting. In each case,
the mesh was folded open in the direction of the flow. No pieces of the mesh seemed to have broken off
and pushed downstream toward the 3-pt valve. I removed the mesh completely in both cases.

I believe that this inline "filter" was added in response to problems with the 3-pt valve on early models. The
screen size is so large, however, that it would not filter anything but large particles, and just how would
large particles get in there? Why wouldn't they get caught by the the main hi-pressure hyd filter? Even
the suction filter on the 4300 seems to have a smaller mesh to it.

Then there is this question: why don't other similar tractors use an inline filter between valves? Makes no
sense to me.

As to the 3-pt valve giving you trouble: take it apart and clean it out. The lever resistance you feel may
indicate some debris in the valve, as you suggest.

 

[arkvet]

Update:

I started the tear down last night and had some interesting findings. The rockshaft itself was basically seized up. After removeing the cover to the control valve and removing the link between the actual rockshaft and the position feedback rod I realized that the "very stiff" rockshaft lever was 100% due to seizing where the shaft entered the control valve. It took an incredible amount of penetrating lubricant, twisting, tapping, etc.... to get it to budge. I finally got it moving laterally so that it could be removed all together. I'm going to have to remove the left wheel (I initially just removed the fender) to get the shaft all the way out.

The other small area that is being a pain is removing the short shaft that goes to the position feedback linkage. There's a "spring pin" that secures the linkage to the shaft and I have no clue on how to remove it. I'm assuming there's a precision "punch" that would make the job easier. I always end up buying as many tools as parts when I get into these kind of things However, from what I can tell I may actually be able to pull the rockshaft without removing that u shaped bar going to the feedback linkage... yet to be determined. However, there's going to be another o-ring in that shaft too, so while I'm there it would probably be wise to pull it and replace.

I haven't removed the control valve itself but can easily depress the big spring / rod that goes into the control valve. Again, it may be working fine but while I'm there I guess I should remove it and replace the 0-rings.

Right now I'm planning to order the replacement parts / o-rings and hopefully (minus my labor) I'll have a relatively inexpensive yet good repair.

The corrosion around the rockshaft "limiter" was horrible. On the parts breakdown there is a very wide rubber washer that well... is gone? Since there is some rust and corrosion on the rockshaft itself I'm planning to replace the whole shaft as it's not too expensive anyway.

 

[arkvet]

In this picture you can see the corrosion between the limiter and the housing to the control valve. The "shaft key" was an absolute pain to remove as it was seized onto the shaft as well.

 

[arkvet]

any tricks on removing that spring pin? If I can't get it out I won't be able to remove the short shaft going to the position feedback linkage. That shaft has an o-ring on it that I'd like to replace and since the shaft is only $15 I'm going to order and replace it too while I'm in there.

 

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So what do you think is the cause of that much rust? Especially since the tractor has not seen salt? How many hours are on your 4300? Any signs of that filter screen anywhere?

 

[dfkrug]

any tricks on removing that spring pin? If I can't get it out I won't be able to
remove the short shaft going to the position feedback linkage.

Not sure which pin you are referring to. JD uses lots of roll pins and double roll pins. If you don't have
a drift with the right diameter, you can take a nail and grind the tip off. If you use a concrete nail, then
the steel is harder/tougher.

If you can't get access with a hammer and a drift, then you may have to remove more stuff.

 

[arkvet]

So what do you think is the cause of that much rust? Especially since the tractor has not seen salt? How many hours are on your 4300? Any signs of that filter screen anywhere?

I have a theory but it may be wrong... In the parts diagram there is a very large rubber washer that goes between the "limiter" and what I would call the housing. The rubber washer is shown to go in the gap where all the corrosion is visible in the picture. I can't find this washer. Either it corroded and fell apart and washed away... Or it was never there! My theory is that this hydraulic screen (referred to in the first part of this thread) blew a long time ago. I bought the tractor at about 1100 hours and I estimate about 1400 now but the hour meter gave out last year. I'm betting that in the past this control valve had a prior issue and during the disassembly / reassembly the rubber washer was left out. From what I can tell this large flat washer would be the only thing keeping this region free from seeping water and corrosion.

Anyway, I can't even identify remnants of a rubber washer. That's my theory.

I'm going to buy a rolled pin punch set and see if I can't knock out that pin.

I will continue updates as I find out more. I worked on the tear down last night from about 10pm to 2am. Owning a business and having 3 children... Time is hard to find. The parts should be at my dealer on Monday. I may find some tinker time around Christmas. We'll see.

Thanks guys!

 

[joecdeere]

kit is long gone, here's the pieces