Before I shot out this post, I did try searching but found nothing but all sorts of stuff on the saginaw rebuilds, etc....

I'm determining that the servo valve is shot hence why my new pump didn't even kick in power steering...so, it's off my '78 F150 4wd...where can I find schematics or diagrams to tearing into it? Should be the same as a saginaw box for a ford, yes?

Can I just pull the piston side of the box near the input shaft off and not full with the rest since it doesn't have an end cap? Now I know why my buds don't fuck with a box....but since I have a ready replacement I'm determined for someone to put me in the right direction and bust my cherry on mine that just came off and if I fuck up, no biggie, I'm still up and running but I need to learn!! Some help please!

Here's a pic of the spool valve and shaft broken down. The box is very simple to disassemble. There's a top cap and an end cap to unbolts and it will come right apart.
http://pic90.picturetrail.com/VOL2182/513809/712472/229717462.jpg

Here's a pic of the spool valve and shaft broken down. The box is very simple to disassemble. There's a top cap and an end cap to unbolts and it will come right apart.
http://pic90.picturetrail.com/VOL2182/513809/712472/229717462.jpg

Just now checking, spent yesterday afternoon after that post disasembling, and you're right, wasn't bad at all, and glad you gave me this info. because that's where I'm currently stumped...I took the snap ring off, now what? Also, just got back from NAPA and ordered a master rebuild kit with all seals, etc...does the actual spool valve in these things ever go bad? Other than alot of fine metal particulates in the fluid coming out of the box, everything looks fine, no wear on the worm gear, etc...thanks for the help!

Another side question, does it matter how the steelies go back in in reference where the worm gear is....looks like there was no difference in size or color of the steelies when disasembling...looks like just shoving them back in when it comes time, yes? That's why I wondered if anyone on here had a complete total step by step teardown and reasembly on file.....

Just now checking, spent yesterday afternoon after that post disasembling, and you're right, wasn't bad at all, and glad you gave me this info. because that's where I'm currently stumped...I took the snap ring off, now what? Also, just got back from NAPA and ordered a master rebuild kit with all seals, etc...does the actual spool valve in these things ever go bad? Other than alot of fine metal particulates in the fluid coming out of the box, everything looks fine, no wear on the worm gear, etc...thanks for the help!

To get it apart that far, there's a pin at the bottom that holds the spool and torsional spring in place inside the main worm shaft. Drive it out and it should slide apart fairly easy depending on how cruddy the spool and sleeve are. Hopefully that won't be bad. The sleeve just rests over that positive stop pin in the lower worm, and will come right off after the inner portion is out of the way.

The clearances in the spool valve are in keeping with standard hydraulic systems, so they are considered critical. They should not wear unless they get scored from contact with metal particals. Even then, I think it would be ok if you polished it back out given the relatively light duty as hydraulics go. Just make sure when its at rest the recirc passages are aligned on center, which they will be if the spring is not tweeked. It shouldn't be as there is a mechanical stop built in at full stroke to avoid over-extending the spring. The spring is a torsional type, which is the long internal rod that was pinned to the worm. Plus make sure it springs right and left ok when its back together.

As far as the balls, I've never seen any difference in them. Now I'm hearing a certain amount may be different, but I've never seen that and it makes no sense to me. I will mic all the ones I have out to see, but I don't expect to find different sizes because that would mean some were taking more load than others. I think the ones with mixed balls were replaced with wrong ones, or new ones were added to old worn ones. Another thing you find mfr's doing is using an odd size that isn't available to the public thereby proprietizing for them.

To put them in, you basically line it up and start packing the balls in there. When enough are in there to make it stable, you can rock it back and forth to get the rest to settle away from the loading holes. When its full, and the recirc tube is full, there should not be room for one more ball if they all are there. If its one or two short it won't hurt it bad, but its best to have it full.

The clearances in the spool valve are in keeping with standard hydraulic systems, so they are considered critical. They should not wear unless they get scored from contact with metal particals. Even then, I think it would be ok if you polished it back out given the relatively light duty as hydraulics go. Just make sure when its at rest the recirc passages are aligned on center which the will be if the spring is not tweeked. It shouldn't be as there is a mechanical stop built in at full stroke to avoid over-extending the spring. The spring is a torsional type, which is the long internal rod that was pinned to the worm. Plus make sure it springs right and left ok when its back together.

As far as the balls, I've never seen any difference in them. Now I'm hearing a certain amount may be different, but I've never seen that and it makes no sense to me. I will mic all the ones I have out to see, but I don't expect to find different sizes because that would mean some were taking more load than others. I think the ones with mixed balls were replaced with wrong ones, or new ones were added to old ones. Another thing you find mfr's doing is using an odd size that isn't available to the public thereby proprietizing for them.

To put them in, you basically line it up and start packing the balls in there. When enough are in there to make it stable, you can rock it back and forth to get the rest to settle away from the loading holes. When its full, and the recirc tube is full, there should not be room for one more ball if they all are there. If its one or two short it won't hurt it bad, but its best to have it full.

Alright, went back to the workbench, I noticed in your pic is a "pin" laying in the left of the photo, yes? Is that the pin on the far end of the rod at the little snap ring that keeps the steelies from rolling out of the worm gear? I'm having trouble releasing the piece beside the rolling bearing in the middle of the whole unit...it's been tapped in places that "locks" in down on the splines....I guess it would help if you let me know in which direction everything is coming off the shaft would be a help, that way I'm not trying to hold or force something that I'm not supposed to, know what I mean?

Alright, went back to the workbench, I noticed in your pic is a "pin" laying in the left of the photo, yes? Is that the pin on the far end of the rod at the little snap ring that keeps the steelies from rolling out of the worm gear? I'm having trouble releasing the piece beside the rolling bearing in the middle of the whole unit...it's been tapped in places that "locks" in down on the splines....I guess it would help if you let me know in which direction everything is coming off the shaft would be a help, that way I'm not trying to hold or force something that I'm not supposed to, know what I mean?

when you say, " make sure it springs right and left when it's time to assemble, so, shouldn't the piston twist right and left now before I start to disasemble? Reason I'm asking, the piston is locked, can't force it to turn in either direction while on the rod, is that what you're talking about? Maybe that's been my trouble all along?

when you say, " make sure it springs right and left when it's time to assemble, so, shouldn't the piston twist right and left now before I start to disasemble? Reason I'm asking, the piston is locked, can't force it to turn in either direction while on the rod, is that what you're talking about? Maybe that's been my trouble all along?

While its out, you can put the very bottom in a vice, and turn the the splined input area and also get the spring action, but I wouldn't do that until you've cleaned it thoroughly in case its dirty. Its too hard just to do by hand, but you want to be very carefull not to damage anything.

If you look at the sleeve, there's a loose hole in it over a pin in the lower worm. In the picture, looking from the bottom, the one in the sleeve its at about 1 o'clock, and the one in the worm is pointing down towards the towel at about 5 o'clock. These are the positive stops between the two pieces, and it won't turn anymore than that.

Alright, went back to the workbench, I noticed in your pic is a "pin" laying in the left of the photo, yes? Is that the pin on the far end of the rod at the little snap ring that keeps the steelies from rolling out of the worm gear? I'm having trouble releasing the piece beside the rolling bearing in the middle of the whole unit...it's been tapped in places that "locks" in down on the splines....I guess it would help if you let me know in which direction everything is coming off the shaft would be a help, that way I'm not trying to hold or force something that I'm not supposed to, know what I mean?

While its out, you can put the very bottom in a vice, and turn the the splined input area and also get the spring action, but I wouldn't do that until you've cleaned it thoroughly in case its dirty. Its too hard just to do by hand, but you want to be very carefull not to damage anything.

If you look at the sleeve, there's a loose hole in it over a pin in the lower worm. In the picture, looking from the bottom, the one in the sleeve its at about 1 o'clock, and the one in the worm is pointing down towards the towel at about 5 o'clock. These are the positive stops between the two pieces, and it won't turn anymore than that.

Ok, gotcha on the pin in the sleeve, I did try a magnet tool but no avail, how else are you pulling that pin out?

Ok, gotcha on the pin in the sleeve, I did try a magnet tool but no avail, how else are you pulling that pin out?

The pin you drive out is at the very bottom. Everything in the pic is fairly relevant to its proper location. the stuff in the back is thrust washers, seals, and stuff. the stop pin does not come out.

The pin you drive out is at the very bottom. Everything in the pic is fairly relevant to its proper location. the stuff in the back is thrust washers, seals, and stuff. the stop pin does not come out.

I know I'm getting annoying, starting from tearing down the worm gear and sleeve over the piston, step by step, how's it done....all I've done right now is removed the snap ring, I'm guessing the little 12 point or so lock nut at the end of the worm gear comes off next before the sleeve and rolling washers come off? How did you get that bastard off as I've no kind of fucked up socket to attempt it and I just broke off the end of a punch chisel trying to pop out the indentions in the "lock nut" I guess to slide it off.......??????

The next step is to drive the pin out at the bottom with a drift punch and seperate the inner from outer. Once the input/spool/torsion bar is pulled from the lower worm, you can slip the sleev to the side and lift it off over the other permanent pin. Once the sleeve is off, you will see that the 12-pt. nut just holds the thrust collar and washers on the worm. A regular 12-pt. box-end wrench will loosen it up if you clamp the body in a vice or something else. Be carefull where you grab it or clamp it. Piece of cake.

I didn't think you would need it, but maybe this pic shows the bottom pin better for you.
http://pic90.picturetrail.com/VOL2182/513809/712472/229525115.jpg

I know I'm getting annoying, starting from tearing down the worm gear and sleeve over the piston, step by step, how's it done....all I've done right now is removed the snap ring, I'm guessing the little 12 point or so lock nut at the end of the worm gear comes off next before the sleeve and rolling washers come off? How did you get that bastard off as I've no kind of fucked up socket to attempt it and I just broke off the end of a punch chisel trying to pop out the indentions in the "lock nut" I guess to slide it off.......??????

Alright, repost, had to run out to the Zone and buy an 1" 1/8th wrench to twist off the lock nut, so after that then driving out the pin on the end, get this, I had to literally take a punch and hammer to whack away to "twist" loose the sleeve because it was completely froze up, hence all the questions on what was turning, etc.....

So there was probably why all of a sudden, my power steering went out, some trash or god knows why that sleeve suddenly froze up...also, after I finally broke that loose enough to slide off, the worm gear has a slight wobble to it like it's warped now, has that been due to excessive heat? Too much pressure? Ever come across these events before?

I'm guessing by now after what I witnessed that this box is fucked unless I can grab a donor worm gear, sleeve and piston setup from another....right?

Either way, really appreciate your feedback and help in the matter, that was my first teardown of a box and literally didn't know what to expect so again, THANK YOU! P.S. I posted some pics of my 78 f150 on the members rides section night before last I think so if you're curious as what I've been cussing the hunter green stepside near the end of the thread is mine....god help me....:shaking: