820 2 cyl powersteering

hey everyone, i'm working on the power steering on my 820. it was leaking oil out where the steering shaft goes in so i had the worm housing and valve off. it hasn't steered the best since i got it last summer either, little to no help steering. it has the later style operating sleeve with out the set screw and the helix adjustment on the end of worm gear. while i had it off i took the steering worm shaft off the operating sleeve and noticed that the 2 cam pins were getting some flat spots so i turned both pins half a turn so they run on fresh surfaces. i did my best to get the operating sleeve end play set to .0015 ( kinda hard to get a dial indicator in there to get an accurate measurement and my indicator only goes to .000. i didn't change the shims for the worm gear end play and it seemed to be with in the .001-.004 range.

tonight i got everything put back on and was trying to adjust it here is what i got: ( i have a 3000 psi gauge in the pressure line like the book shows (lowest pressure i could find it the farm store))

tried to center steering valve hard to do by the gauge but got it so it is equally hard to turn each way and while turning each way the pressure on the gauge is with in 50-100 psi of each other.

with the valve where i have it now the highest pressure i can get is 500 psi ( i haven't tried adjusting relief valve yet and here is why: at one point i had the valve off center so it turned easy to the left and when the valve was in that position i got about 1100-1150 psi while holding the wheel all the way to the left.

also when i started making adjustments the first thing i had to do was turn the flow valve in so far that i don't think the cap will thread on any more to get the gauge to read any pressure to center the valve. at one point i thought i had it centered and backed out the flow valve to get 130 psi, while i was turning screw out the pressure was raising and dropping like the screw had a high spot or something that pushed the valve in when it came across a spot on the flow valve.

the correct John Deere power steering oil seemed to be foamy and there seemed to be some pressure in the reservoir when i took the dipstick out to check the oil level after the first time running it since assembly, i suppose my pump seals are leaking and sucking air?

so what does anyone think i should try next to get it working good in each direction and getting the pressure up where it should be? do i have an end play not adjusted right? kind of seems to me that the operating sleeve isn't moving far enough to move the valve as far as it should in each direction and i'm not sure what adjustment would solve that? the flow valve also has me kinda puzzled.

not sure if it has any affect on power steering operation but i did remove some of the shims that adjust worm gear back lash, pack was .078 and i took it down to .052 and it still seemed like the worm gear turned more that the book specified but i didn't want to get to carried away with changing that adjustment, it still turned free with out any tight spots.

i think my email is open if someone wants to talk me through it over the phone email me your number or send me an email and ill send you mine
 

Flow control valve is to prevent too fast and too far of steering response at wide open throttle .
How much pre-load is there on the spring ?
 
on the centering spring or the spring in the flow control? i didn't change the centering spring. how do i tell how much pre-load is on flow spring?
 
not On the operating sleeve end play, just tighten it until it binds, then back off slightly until it is free and works. I agree...it is impossible to get accurate reading with dial indicator because of existing wear. I recently did my 720D steering and it works fine.

On the flow control, the book says to turn in until it contacts spring, then two more turns as a starting point. I did this and just had to add another turn to get good response at an idle. That is the purpose...provide adequate pressure at idle and at full throttle. Don't get it too tight or you will have flutter.

It sounds like your pressure is OK. You should not get max until it is turned to an extreme. The bubbles may indicate a leak on the return pie.

Good luck,

RandyT
 
ok, i'll try that on the sleeve.

i searched the archived posts and someone said if you push or pull on the steering wheel while turning and it improves the turning that that is a sign of to much worm gear end play. i trued that and it made a huge difference so i pulled the pony starter off so i can get in there through the cap plug and checked the end play again, it was pretty loose, i have taken 20 something thousandths shims out, think i pretty well had it and the roller bearing got out of place on my last install to check and wrecked a roller. tomorrow i'll call Deere and a bearing house and see if anyone has one, if not ill have to decide if i want to run it with one roller missing or wait a few days for a new bearing.

ill try checking over the suction line, i haven't noticed any leaks on the lines but it is moist in the pump area, not sure if from steering pump or water pump though.
 

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