Ford 850 hydraulics

Hello guys, I hope someone can give me a little guidance here. The 3 point lift arms will go all the way to the top when the lift handle is only at the halfway point in the quadrant while in position control. The lift arms will lift incrementally with the lift handle until I reach the halfway point and then they will go all the way to the top. This is on an early 1954 850 with the vane pump.

Last weekend I pulled the top cover and saw that the cam follower pin was worn halfway through, so I replaced it, hoping that was what was wrong. Unfortunately upon putting it back together it does exactly the same thing. I had lift problems with my 1961 4000 and upon replacing the cam pin, it fixed it. No,luck here though.

I do have Zanes lift repair booklet that I used on the 4000 with the feeler guage. So I will pull the cover again follow the adjustment procedure for the lift.

So my question is, is there anything else I should be looking at besides doing the adjustments, while I have the cover off?

I did notice that the threaded linkage attached to the turnbuckle on the control valve has a slight bow to it. Would that also be contributing to the issue?

Thanks for your help in advance

Is the cam itself, where the pin rides, worn? You should be able to see the original profile of the cam on the part past the end of the pin that doesn't have anything wearing against it. If the part that the pin rides on is worn down from that original profile then you should build it back up with a welder a little above the original profile and then grind it down smooth to match the original profile.

Also, you should always go through the adjustments every time you have the lift cover off just because they are easy to do compared to removing and reinstalling the cover.

(quoted from post at 11:31:38 09/19/16) Is the cam itself, where the pin rides, worn? You should be able to see the original profile of the cam on the part past the end of the pin that doesn't have anything wearing against it. If the part that the pin rides on is worn down from that original profile then you should build it back up with a welder a little above the original profile and then grind it down smooth to match the original profile.

Also, you should always go through the adjustments every time you have the lift cover off just because they are easy to do compared to removing and reinstalling the cover.

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Thanks for responding Sean, I looked at the cam and I did not see any appreciable wear on it. I hopefully will pull the cover this weekend and do the adjustments and check the cam again. Hopefully the adjustment will correct this issue.

So I finally was able to get the lift cover off again. The nut on the end of the draft pin was loose and about to come if so,I tightened that down. The triangle plate with the pin behind the large draft spring was worn, so I substituted a washer to make up the difference in the wear. The threaded rod that attaches to turn buckle and the control valve was bent a bit so I had to straighten that. Then I went I and adjusted the lift according to Zanes manual and feeler guage. I couldn't get the adjustments prefect due to wear in the various parts. But after getting it close and putting it back together she works 10 times better. The lift will follow the the touch control in the quadrant almost perfectly.

I couldn't believe how off the adjustments were in the lift cover. We have owned this tractor since 1968 and I was told the lift was never tinkered with. Also, I checked the cam that rides on the follower pin and there was no wear that I could feel or see on it.