Hydraulic Lift Adjustment - Lift Arm Angle

Orion231 · Oct 17, 2020

So, I had to change top covers and the used one I bought doesn't have witness marks for the lift arm position in the up position. The quadrant had witness marks but they are way off from my old one.. I set the quadrant slide adjustment at about center of the forward/back slot. Now I am trying to adjust the lift control arm and draft control. I got the position control spring set to 3.667 but couldn't get it to the spec of 3.5625. Close enough I think. The manual FO-4 says to position the lift arms at the witness marks in the up position so that the draft control spring can be adjusted. Since I don't have witness marks on the arms and top cover, does anyone know what the angle should be or another way to get the arms to the right position to adjust the draft control spring??

Thanks...

Bruce(VA) · Oct 18, 2020

" Close enough I think. "

I don't think so.

You are trying to adjust that lift w/o a jig, right?

I did that once. After about 6 tries.

Buy a jig. nnalert's has them.
75 Tips

Orion231 · Oct 19, 2020

Bump, it says there is a reply but I can't see it. So, can you re-post your reply or if there is some else out there that has an idea how to set the lift arms to the right angle for the adjustment could you post the method. It would be greatly appreciated..

Thanks...

HFJ · Oct 19, 2020

hit the reply button, and then look at the "topic review" section on the posting page, that often does the trick.

here's this one, from Bruce (VA):

[i:ebc91d8a55]" Close enough I think. "

I don't think so.

You are trying to adjust that lift w/o a jig, right?

I did that once. After about 6 tries.

Buy a jig. ****** has them.[/i:ebc91d8a55]

i don't know who ****** is. the invisible post is the result of bruce mentioning a name that's on a blocklist for modern view.

Orion231 · Oct 19, 2020

Great, thanks for clearing that up...

I have searched everywhere but haven't found any reference for the angle of the lift arms when the witness marks are aligned. I am assuming that since witness marks are used for the adjustments, then the adjustments are made with the lift arms short of their full travel with the cover off. That makes sense since at full up travel with the cover on the bench pushes the RAM arm back too far....

Looks like I need someone with a correct adjustment to raise their lift until the witness marks align and then give me a reference measurement from somewhere on the top cover to somewhere on the lift arms so I can replicate that.. I could then create new witness marks for the adjustment.

I saw something about using a threaded bar through both lift arms and dropping the arms down setting the bar against the top of the control spring but that was on an NAA so guessing it doesn't apply to the 8N (mine is a '51).. But, something like that is what I need I think.

JMOR · Oct 19, 2020

Yes, that is NAA. With no other to rely on, if it were me, I would run the piston out to end of cylinder & maybe another 1/8 to 1/4 inch protruding and see where lift arms are at that point. I would call that full up and get on with adjustments. Arms can be lifted above this, but connecting rod on rocker will no longer be in contact with piston. My 2 cents worth!

Orion231 · Oct 22, 2020

Thanks, I went with your suggestion. The top cover is now completely rebuilt and adjusted per the FO-4 manual. It is ready to go back on once the parts arrive for the pump, I get it rebuilt, and get it installed.

Hydraulic Lift Adjustment - Lift Arm Angle

Orion231

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Bruce(VA)

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Orion231

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HFJ

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Orion231

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JMOR

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