JD 620 Power Steering Pedestal

Jklconnell

New User
I was wondering if anyone could help me figure out why I cannot remove the steering gear the is located at the top of the power steering pedestal. I have removed the pedestal from the tractor and I have the lower casting supported so that the shaft can clear the housing, but I cannot seem to break the shaft loose from the upper gear.
 
I can email you some material from the
factory power steering manual. I found it
really helpful when I did mine. Let me know,
my email is open. Hugh
 
Oh, for one thing, have you removed the
vanes from the main shaft? I'd they are
still in place, that is the problem. I
highly recommend the factory power steering
manual. Hugh
 
(quoted from post at 20:09:53 07/17/16) Oh, for one thing, have you removed the
vanes from the main shaft? I'd they are
still in place, that is the problem. I
highly recommend the factory power steering
manual. Hugh

I have not removed the vanes as of yet because I cannot separate the pedestal without removing the upper spur gear. Am I doing something wrong? I had read the manual and it looks like I need to remove the upper spur gear before I can separate the unit. I would appreciate any documentation or advice.
 
Been awhile since I did one. IIRC with it laying on the floor or still in the tractor may be better. First measure and record the amount of end play you have so you can adjust it at assembly time via shims. I use another bolt extra long screwed into where the old one was so it sticks out above the casting. You have to place some sort of wedges or blocks under the gear to hold it up and then give that bolt a good hard whack from a sledge ! it should pop free. Then you can proceed tearing it apart the rest of the way.
 
(quoted from post at 06:02:34 07/18/16) Been awhile since I did one. IIRC with it laying on the floor or still in the tractor may be better. First measure and record the amount of end play you have so you can adjust it at assembly time via shims. I use another bolt extra long screwed into where the old one was so it sticks out above the casting. You have to place some sort of wedges or blocks under the gear to hold it up and then give that bolt a good hard whack from a sledge ! it should pop free. Then you can proceed tearing it apart the rest of the way.

I had removed the bolt and used a punch with a spacer between the punch and the shaft and I heated up the spur gear with MAP gas and I cannot break it loose. I had also used some penetrating oil as well. I made some wood blocks to support the pedestal like it were in the tractor so that the shaft can drop down through the bottom. I have not put any wood shims under the gear as I see that it is already supported by the shims. I'm wondering if putting a longer bolt in the top like you have mentioned might help me. Not sure, but it's worth a try. I just do not remember what size bolt that it was and I'm at work right now:( How far should the shaft drop once it does break loose?
 
You are likely bottoming out the vanes inside the housing at the same time the gear touches the shims. You need to have the gear take the full force of removal.
For some reason I think it is a 3/4" coarse thread bolt. I'd get a 5/8" too just to be safe as I may be wrong. It is one or the other as my bolt bin has those and I pulled one from there and reused it a few times as my designated hitter !
 
(quoted from post at 06:46:27 07/18/16) You are likely bottoming out the vanes inside the housing at the same time the gear touches the shims. You need to have the gear take the full force of removal.
For some reason I think it is a 3/4" coarse thread bolt. I'd get a 5/8" too just to be safe as I may be wrong. It is one or the other as my bolt bin has those and I pulled one from there and reused it a few times as my designated hitter !

That makes sense, I will give this a try and let you know how it works. Thank you
 
(quoted from post at 06:51:35 07/18/16)
(quoted from post at 06:46:27 07/18/16) You are likely bottoming out the vanes inside the housing at the same time the gear touches the shims. You need to have the gear take the full force of removal.
For some reason I think it is a 3/4" coarse thread bolt. I'd get a 5/8" too just to be safe as I may be wrong. It is one or the other as my bolt bin has those and I pulled one from there and reused it a few times as my designated hitter !

That makes sense, I will give this a try and let you know how it works. Thank you

Guy's I was able to dismantle the unit last night and you were correct both were correct. I noticed that I have several scratches on the Steering spindle, Steering cylinder and the Spindle Quill and I was wondering if I would be able to machine some of these components and maybe just emery cloth the steering spindle? I'm not sure how much I can machine the cylinder or the top of the spindle quill. I think that I have caused these scratches from trying to dismantle my unit:( I have also attached some pictures for your reference. I have also noticed that my pedestal does not have a #74 bushing inside of it but it does have the o-ring. I'm not sure what to do about this, but I am ope to suggestions. Note: I do have the #70 bushing at the top of my pedestal and I have the #90 thrust bearing at the lower end. Do you normally replace the thrust bearing?
 
Don't feel bad, I did the same thing with
mine, that's what made me think of it! I
took my quill to a machine shop and they
milled off about .010 inch, and it has
worked out perfectly since putting it back
together. If you want you can call me at
318-465-1472. Hugh
 
Those are steel bushings and it is very hard to see the parting line to define where they are. I'm betting you have them. I have had at least the bottom quill resurfaced before. Just make sure they take the same amount off the surface and then the step of the mounting surface to keep it all equal where it seals up. If not bad a sheet of #80 grit wrapped around a large file and work over the surface may just clean it up ? If the bearing balls look smooth I'd reuse it. May not even be able to buy them anymore ? Be careful with it as it can fall apart ! Look for the thrust side as it is only to be installed one way as to take the thrust pushing up into it.
 
(quoted from post at 08:05:49 07/19/16) Those are steel bushings and it is very hard to see the parting line to define where they are. I'm betting you have them. I have had at least the bottom quill resurfaced before. Just make sure they take the same amount off the surface and then the step of the mounting surface to keep it all equal where it seals up. If not bad a sheet of #80 grit wrapped around a large file and work over the surface may just clean it up ? If the bearing balls look smooth I'd reuse it. May not even be able to buy them anymore ? Be careful with it as it can fall apart ! Look for the thrust side as it is only to be installed one way as to take the thrust pushing up into it.

I'm thinking of leaving the steel bushing in place then as they don't look too bad and I will polish the shaft. I don't want to make things worse for me if that makes sense. Do you know how much I could remove on the inside of the cylinder by chance? Can I also take a file to the edges of the details that hold the wipers so that I don't mark up anything during assembly?
 
I know what you mean. Sometimes thing get worse if you try doing too much and now parts are getting even harder to get.
I never did anymore to the inside of the cylinder then just use an engine cyl. hone on them. You sure would not want to remove anything much as you will loose the ability of it to hold pressure. The most I ever did to the metal vanes is to run them on my wire wheel to clean them up of any burrs. I'd hate to ruin them by removing material. Soak the rubbers in HOT water and use soap and a small screwdriver carefully and slip them on.
 
(quoted from post at 10:41:01 07/20/16) I know what you mean. Sometimes thing get worse if you try doing too much and now parts are getting even harder to get.
I never did anymore to the inside of the cylinder then just use an engine cyl. hone on them. You sure would not want to remove anything much as you will loose the ability of it to hold pressure. The most I ever did to the metal vanes is to run them on my wire wheel to clean them up of any burrs. I'd hate to ruin them by removing material. Soak the rubbers in HOT water and use soap and a small screwdriver carefully and slip them on.

Ok, I understand what you are saying. I have checked on the pricing and availability and they are very expensive. I don't mind replacing some of the components, but I'm concerned about causing a bigger issue just trying to press it out when i cannot even see it. I will replace the upper bushing and I just cleaned the lower bearing and it looks good. It almost looks like it is missing a ball, but I'm not sure if that is how they made them back then or not but the unit was working good without it. The bearing is $180.00 from John Deere:( Should I assemble this unit on the bench or the tractor? The upper hydraulic valve has been working good and I'm wondering if I should rebuild that as well while I have everything torn apart?
 
I think that bearing does look like that as there is not a cage to hold the balls separated.
If the valve was working you may ? be better off leaving it alone ? I however cannot leave well enough alone and would tear it apart, but I have been into these before too !
If you do get into the valve NEVER EVER knock the crisp edges off of the spool valve ! I knew a guy who did this and it ruined his steering and had to get another one. I lightly polish the flat surface to make sure it does not stick but keep the edges !
I don't think it matters where you assemble it. I think I have done both ? depends how much height you have to slip the top section over the shaft. The bottom part would about have to be done first on the bench so as to keep the shaft from falling out until you get the vane bolted to it.
I hope you got the service manual for that unit. I'd never tackle one without it by my side.
 
(quoted from post at 13:40:29 07/20/16) I think that bearing does look like that as there is not a cage to hold the balls separated.
If the valve was working you may ? be better off leaving it alone ? I however cannot leave well enough alone and would tear it apart, but I have been into these before too !
If you do get into the valve NEVER EVER knock the crisp edges off of the spool valve ! I knew a guy who did this and it ruined his steering and had to get another one. I lightly polish the flat surface to make sure it does not stick but keep the edges !
I don't think it matters where you assemble it. I think I have done both ? depends how much height you have to slip the top section over the shaft. The bottom part would about have to be done first on the bench so as to keep the shaft from falling out until you get the vane bolted to it.
I hope you got the service manual for that unit. I'd never tackle one without it by my side.
I do have a manual that encompasses everything so I have been reading that, but it sure does not give me all of the tips like you have given me and I appreciate all of your help and advice on this. These parts are too expensive to make a mistake. I had just finished the restoration of this tractor last year which was sitting in our cow barn for 30 years not running with 4 flat tires. Since the restoration the tractor it has been running great, but then my lower steering pedestal started to leak and this was one thing that I did not rebuild when I went through the tractor along with the PTO clutches. I guess that if I sat around for 30 years I would have some issues as well.
 
(quoted from post at 10:41:01 07/20/16) I know what you mean. Sometimes thing get worse if you try doing too much and now parts are getting even harder to get.
I never did anymore to the inside of the cylinder then just use an engine cyl. hone on them. You sure would not want to remove anything much as you will loose the ability of it to hold pressure. The most I ever did to the metal vanes is to run them on my wire wheel to clean them up of any burrs. I'd hate to ruin them by removing material. Soak the rubbers in HOT water and use soap and a small screwdriver carefully and slip them on.

Mike,

I started to put everything together last night and I noticed that my book tells me to place a shim between the shaft and the bracket for the vanes, so I did. My parts book tells me that this was for the older serial numbers, but the repair manual says that if it was not there during disassembly to make sure that I install one so I did. The manual is telling me to torque the bolts down to 208 for if I have no dowels and 275 with dowels I believe. I'm not sure what dowels they are speaking of. Can you please help me? Note: I can also be reached at 248-318-1150 if that is easier.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top