[michael j]

While cleaning and painting the front clip of my Chevelle earlier this year, I decided to go deeper into the engine bay and give her the cleaning and detailing that I've been meaning to do since 1998. The first major component, as I work my way towards the firewall, was the Saginaw power steering gear box. In the past someone painted mine blue, I'm assuming to match the exterior color. I had had a leaking PS resevior, cracked at the return hose fitting, which has been replaced and have replaced the hoses, so I thought a rebuild of the gearbox was in order. After looking at the overhaul manual and doing some net reading, I came across a GOLDMINE of information on YouTube Many thanks to hutchhiperf on YouTube for this series of videos concerning the rebuild and adjustment of a Saginaw Power Steering Gearbox:

Tear Down
https://youtu.be/WX119EtadWM?list=PLvTshlwDi1UF8ueUn-v_YUyqPWJa3Ser-

Installing Seals
https://youtu.be/iqqqdQMljm0?list=PLvTshlwDi1UF8ueUn-v_YUyqPWJa3Ser-

Rack Piston
https://youtu.be/l3GAggBjHJU?list=PLvTshlwDi1UF8ueUn-v_YUyqPWJa3Ser-

Final assembly
https://youtu.be/0F2eHlRnZfk?list=PLvTshlwDi1UF8ueUn-v_YUyqPWJa3Ser-

Adjustments
https://youtu.be/UJ-89YhvAXU?list=PLvTshlwDi1UF8ueUn-v_YUyqPWJa3Ser-

There are two types of kit you can buy, one is a kit of seals, for a lower level refresh, and the other is more a intensive, full-on rebuild kit which includes seals and replacement bearings. I opted for the full rebuild kit to do my job.

All in all the process isn't terribly difficult. I will call out a few areas that I found were different than Hutchhiperf's video series and things that found made my job easier.

My results:

You can also view the gallery of photos I took of my own work, with descriptive and hopeful helpful captions here:

https://picasaweb.google.com/106242937059319515061/ChevellePowerSteeringRebuild#6186708719696996050

 

[michael j]

Special Tools

All in all the process isn't terribly difficult. I will call out a few areas that I found were different than Hutchhiperf's video series and things that found made my job easier.

Firstly, make your own spanner wrench. Hutchhiperf uses needle nose pliers, which is a bit unwieldy for me. I used two pieces of metal bracket/strapping with three bolts. One to hold it together and two longer ones which will act as your tool's grippers. Be sure the long bolts you use fit into the ports on the plug. You can see my spanner wrench here:

I also ad-libbed a tool to keep all of the ball bearings in place along the insides of the rack piston during assembly. I used a 1/4" drive 7/16" deep socket on an extension to fill the space, which fit perfectly and held everything in place.

 

[michael j]

Differences in details from the YouTube videos

If you're working on a gearbox of similar vintage to mine, don't be alarmed that you only find 22 ball bearings inside the rack piston. That's what I and other people have had as well. It is vitally important to identify the "dark" balls from the "chrome" balls. The darks are slightly smaller (by like less than a .001") and you have to reassemble in alternating fashion: dark-chrome-dark-chrome-etc. Failure to do this will cause excessive wear and damage as two or more similarly sized/coated balls will wear against each other.

My work went almost exactly like what is shown in the videos, except for when I got to the valve spool, as seen towards the end of the teardown video and especially in the Installing Seals video. On my 70 Chevelle, the valve spool is held in place on to the stub shaft with a coil spring. The diameter of the coil spring has to be expanded to get it over a lip on the plug shaft to get it off and to release the valve spool.

Assembly of the valve body is extremely tricky and can jam easily. I needed to clean both the interior of the valve body and the exterior of the valve spool many times and heavily lubricate with power steering fluid. I assembled the spool into body first, the the plug shaft into valve body THEN get the spring back over the plug shaft to hold the valve spool in place. That is not as easy as it sounds.

 

[michael j]

Tips For Rebuilding Rack Piston

Rack Piston Seal
Replace all rack piston seals before installing ball bearings!

I had to install the big teflon seal on the rack piston twice. The first time I must have stretched it slightly as it had a bit of a bulge. When I tried to install into the rack piston into the casing, that bulge snagged and I ended up cutting off a sliver of teflon. I should have known, because the piston met resistance and I pushed too hard. For my second teflon seal (I had to buy ANOTHER seal kit to replace it!) I soaked the seal first in boiling water to expand it slightly with heat. It went onto the piston easier and there was less bulge when cooled. For insertion I suggest using an engine piston ring compressor to avoid damaging the seal.

Rack Piston Ball Bearings
Installing the ball bearings into the rack piston really is the catch. I had issue with the grease causing drag so that after 8 or 10 bearings had been inserted, they refused to stay in their track and would pop up. Here is how I was able to complete this leg:

I inserted just the worm gear into the rack as it is supposed to go. Once fully inserted, I turned the worm until its groove matched up with the ports in the rack. This essentially completes the race within which the ball bearings move. I would insert a small amount of grease before each ball is inserted and push a ball in with a small drift pin, giving the worm gear a little bit of rotational jiggle to help with alignment and to coax the balls in. The rotational jiggle gets to be important around the 12th ball, and helps draw the bearings into the race channel. It is important that you do not allow balls past either of the two ports. You can coax the balls in and out of the channel with similar rotation of the worm shaft.

Once all balls have been inserted and the u-channel has been reinstalled, you can rotate the worm shaft out. As you remove the worm shaft, you should insert a place holder, be it the taped up 5/16 hose hutchhiperf recommends, the special tool if you can find it, or something else. Instead of the tape-wrapped tubing, I used a 1/4" drive 7/16" deep socket on an extension to fill the space, which fit perfectly and held everything in place.

The ball bearings are the real trick to this entire job. I attempted their insertion over 10 times! Every time one or more would drop out I had to start over, cleaning each bearing of grease and sorting each bearing by color. It was because of my multiple attempts (with many bad words used) that I came up with the idea to utilize the worm gear to help initial assembly.

 

[michael j]

Rag Joint

This lump of metal can look pretty nasty and rusty, but it is easy to pull apart to clean/paint.

My jag joint broke down into three pieces: a cast iron piece, a cast iron mounted on rubber, and a stamped stainless steel piece. Orientation of the two cast iron pieces is a very easy as the two bolts which hold the pieces together are different sizes. It can only sandwich together ONE WAY!

Also, final assembly with gearbox and steering shaft also go one way thanks to the use of bolt recesses in the stub shaft of the gearbox and the intermediate steering column shaft. The bolt connecting to the gearbox stub shaft will point toward the engine. The bolt connecting to the intermediate steering shaft will point straight up.

The one potential head scratcher is the stamped steel piece. It resides on side that faces the gearbox and is positioned out-board, allowing mounting bolt access on the engine-side.

 

[michael j]

Other tips

Installing Pitman Shaft into case

It should be stated that reassembly in many areas is simplified by the fact that pieces can only go together one way. The rack piston and pitman arm shaft will only mesh together when the assembly is basically at dead center. This simplifies setup on vehicle, too.

Pitman arm shaft going in. These teeth interface with the rack piston.

To ease the insertion of the pitman shaft, I used the rag joint as a grip to wiggle the input shaft/plug shaft back and forth. This motion was translated down to the rack piston via the worm gear and helped to align the rack with the pitman. You'll find that the rack piston may also need to spin inside the bore to align. The wiggle motion helps accomplish this.

 

[ratt69ss]

Good job looks great. I did the same following the same video. Wasn't difficult at all. I think I paid around $60 for the rebuild kit. Rather do it myself and save a bunch of money then buy a rebuilt one for $375.00 or so. :yes:

 

[michael j]

Thanks, Chuck. You are correct, it's not really difficult. I got my full rebuild kit from rockauto.com. It was an ACDelco kit and it cost about $34USD. As stated above and shown in my photo galleries I damaged a large teflon seal during one of my first reassembly attempts. I purchased an Edelmann seal kit for $19 to replace that one piece. Not counting paints and cleaners I came in at about $55. Sooooo much better than $375, I agree. The money saved on this job is better spent on things I can't do, like getting my master cylinder sleeved.

I will reiterate for the sake of a quick summary is that the three main areas that may cause difficulties are installing the teflon seal onto the rack piston, preventing damage to said seal on installation into the casing, and assembling the rack piston's ball bearings. Being extra mindful of those three aspects and the job should go pretty well.

 

[dogsridewith]

Pittman Arm Puller for 1970 Saginaw Power Steering Gearbox

I'm in central PA and need to pull the Pitman Arm on a 71 within a week or two max. Any suggestion on source for a meaty rigid-body puller that is likely to work? (Factory manual shows two types...a two arm adjustable will not pull hard enough, and, I believe, tries to distort the part it is trying to remove, making it tighter.)
(Great thread, and if this post is too off-topic, just say and I'll move it.) Thanks.

 

[Tom Mobley]

This will normally do it:

Tie Rod and Pitman Arm Puller

use quality engine oil on the threads and a little dab of wheel bearing grease on the tip. This tool is OK for occasional use.

 

[Don B]

Great write up and nice job,I know I sure get a lot of satisfaction doing stuff myself and improvising as ness. along the way.

 

[Tom Mobley]

back to the top, this is a good write-up. the u-boob vids are good too.

Thanks michael j

 

[gilbert310]

I bought a rebuilt box with these numbers 5691676 do you know what size rag joint fits tried a 3/4 30 spline and a 13/16 and neither fit.

 

[65cayne]

While cleaning and painting the front clip of my Chevelle earlier this year, I decided to go deeper into the engine bay and give her the cleaning and detailing that I've been meaning to do since 1998. The first major component, as I work my way towards the firewall, was the Saginaw power steering gear box. In the past someone painted mine blue, I'm assuming to match the exterior color. I had had a leaking PS resevior, cracked at the return hose fitting, which has been replaced and have replaced the hoses, so I thought a rebuild of the gearbox was in order. After looking at the overhaul manual and doing some net reading, I came across a GOLDMINE of information on YouTube Many thanks to hutchhiperf on YouTube for this series of videos concerning the rebuild and adjustment of a Saginaw Power Steering Gearbox.....

Old thread but I wanted to say thanks to Michael J for this post. It was a great help on my Saginaw rebuild. It does take some patience but is doable. Some tips from my build...

1) Pay attention to placement and orientation of shaft seals during disassembly. I used a 30mm socket the drive out the pitman bearing/seals. It is the closest in size (bearing pn BH-2020, $13 from Motion Industries if you destroy it like I did). My kit did not have bearings. Thoroughly clean everything after disassembly.
2) Install the teflon seals and let it sit for a day or two for them to relax back to their natural shape. Mine stretched a little upon install.
3) if you cant get the access cover off the piston (like me), grease the inside with some heavy grease and install the worm gear. Then insert the circulating balls one at a time (I had 22 all the same color/size). This part takes some patience as Michael notes. Then carefully unscrew the worm gear.. if you are careful during final assembly, they will stay in place and you can realign the worm gear with the balls similar to catching the first thread on a bolt.

Patience and a little luck.

 

[michael j]

Old thread but I wanted to say thanks to Michael J for this post. It was a great help on my Saginaw rebuild. It does take some patience but is doable. Some tips from my build...

Rock on, man! Thank you, and nice job! Did you polish the end-plug?

 

[65cayne]

Rock on, man! Thank you, and nice job! Did you polish the end-plug?

Yes I did. My intent was to just clean it up and I got carried away on the buffing wheel.

 

[Rmchevelle]

........SEE POST #1^^^^^^^^^^^^^^^^^^^

Old thread but I wanted to say thanks to Michael J for this post. It was a great help on my Saginaw rebuild. It does take some patience but is doable. Some tips from my build...


Patience and a little luck.

WARNING: Old thread....

But this should be a sticky in the "Brakes, Suspension, Steering" forum which already has a lot of sticky's but this is a valuable thread! Hope the mods can find "sticky" room for this.

Good job, michael j AND 65cayne!!!

 

[boltupal]

Tips For Rebuilding Rack Piston

Rack Piston Seal
Replace all rack piston seals before installing ball bearings!

I had to install the big teflon seal on the rack piston twice. The first time I must have stretched it slightly as it had a bit of a bulge. When I tried to install into the rack piston into the casing, that bulge snagged and I ended up cutting off a sliver of teflon. I should have known, because the piston met resistance and I pushed too hard. For my second teflon seal (I had to buy ANOTHER seal kit to replace it!) I soaked the seal first in boiling water to expand it slightly with heat. It went onto the piston easier and there was less bulge when cooled. For insertion I suggest using an engine piston ring compressor to avoid damaging the seal.

Rack Piston Ball Bearings
Installing the ball bearings into the rack piston really is the catch. I had issue with the grease causing drag so that after 8 or 10 bearings had been inserted, they refused to stay in their track and would pop up. Here is how I was able to complete this leg:

I inserted just the worm gear into the rack as it is supposed to go. Once fully inserted, I turned the worm until its groove matched up with the ports in the rack. This essentially completes the race within which the ball bearings move. I would insert a small amount of grease before each ball is inserted and push a ball in with a small drift pin, giving the worm gear a little bit of rotational jiggle to help with alignment and to coax the balls in. The rotational jiggle gets to be important around the 12th ball, and helps draw the bearings into the race channel. It is important that you do not allow balls past either of the two ports. You can coax the balls in and out of the channel with similar rotation of the worm shaft.

Once all balls have been inserted and the u-channel has been reinstalled, you can rotate the worm shaft out. As you remove the worm shaft, you should insert a place holder, be it the taped up 5/16 hose hutchhiperf recommends, the special tool if you can find it, or something else. Instead of the tape-wrapped tubing, I used a 1/4" drive 7/16" deep socket on an extension to fill the space, which fit perfectly and held everything in place.

The ball bearings are the real trick to this entire job. I attempted their insertion over 10 times! Every time one or more would drop out I had to start over, cleaning each bearing of grease and sorting each bearing by color. It was because of my multiple attempts (with many bad words used) that I came up with the idea to utilize the worm gear to help initial assembly.

Thanks for the info, im about to do this rebuild to my 70 Camaro.

 

[Fisherguy]

My results:

You can also view the gallery of photos I took of my own work, with descriptive and hopeful helpful captions here:

Album Archive

That looks great!

I'm trying to track down an original looking box like that for my 69 which has manual steering, having a hard time finding one. Some look good but don't have the Saginaw "S" on the lid, some are painted black and you don't know what you're getting, some don't have the S on the bottom in the casting by the pitman arm either. Apparently the ones sold on Ebay are made in China, I'd prefer not to use on of those on my 50 year old car.

Anyone know where I could look for one?

Were any of the gears inside your worn out?

Assume by now it's back in the car, working out so far?

 

[65cayne]

For mine, nothing was mechanically worn out. So it just needed to be disassembled, thoroughly cleaned, and a carefully re-assembled with new bearing (only because I destroyed mine in the process) and soft parts. It's installed and driving without issue.