Best options for GMT400 large bore steering box

[dbrannon79]

Guys, I wanted to ask the question since I am going to need to replace my steering box on my 95 truck. what is the better option that won't break a poor mans bank account for getting a good no so sloppy steering box? I would like to get a new one but not sure where to go or what brand is better. then there is always pulling one from a pick a part yard and rebuilding it with a good seal kit.

I think the mistake I made was when I replaced the original gear box with a rebuilt one from the auto parts. it lasted for a bit but started getting very sloppy. I later learned how the re-builders (A1-Cardone) like to mix and match parts in them, slapping in a seal kit and calling them good. when I pulled it off and rebuilt it my self I noticed the gear section on the piston having some flashing or what looked like wear on it in such a way that the edges had sharp fold overs on on side. the sector shaft was fine and not worn like this.

The funny thing is I can deal with a little sloppiness but what this gear box is doing is when the wheels are centered straight and going down the road, the steering wheel wants to turn slightly left or right as if the the box's absolute center is on a ridge trying to balance or better explain it it wants to teeter like a sea-saw naturally falling one way or the other till it's off that ridge. I think this has a lot to do with what I am feeling and calling "bump steer".

I have done the alignment multiple times using a couple levels and tape measures, I even did the 93 truck in this same manner and it drives like a dream other than the rag joint is wore out! this truck has no rag joint, it's a u-joint in that place. After doing the same alignment on both trucks and having one drive perfectly fine while this one feels like it has "no center" going down the road leads me to believe the gear box is to blame and there is no fixing it.

I will also add that I have done Ferm's procedure a couple of times on setting the gear box preload. also playing with this (loosening and tightening preload) has had no effect other than adding to the sloppiness or making it too tight.

Rebuilding one of these gear boxes is fairly simple including replacing the sector shaft needle bearing. I am wondering what kind of luck I would have by pulling one with the right size piston from a salvage yard and going through it while hoping I find one that still has "matched" internals. it's not that difficult to pop off the sector shaft cover while out in the JY and look at them before bringing it home. I did pull one out there before but got one with the smaller piston, paid $60 for it. it has no issues other than it makes the steering too stiff due to the small piston in it.

Yall give me some thoughts here.... the problem with finding NEW for these rigs is getting tough, when we do find it, it's priced like gold. it's this or the cost of a little extra time and another $60-70 and some fuel.

 

[ak diesel driver]

I'm saving up for the PSC box

 

[dbrannon79]

Today I ventured out to the pick a part yard and found a unmolested GM large bore steering gear box for the 95. it still had the GM sticker on it with the part number, but it pealed off when I power washed it. GM part number 26068771.

I cleaned it up and flushed out the fluid that was in it on the bench. tried to feel the gear lash play by holding the steering shaft pinion in place while applying pressure on the pitman shaft pinion. there was a little play but as i turned the steering pinion in different positions and re-checking, the play was the same, left lock, center, and right lock. unlike I remember how the box is that is on my truck now. gets stiff in the center and then sloppy the further out to left or right lock. spinning it back n fourth felt smooth and moved with ease.

I am reluctant to even attempt opening it up for a rebuild and leaning more towards just installing it as is and see what it does and if my steering gets any better.

 

[MrMarty51]

I remember rebuilding some of the steering gear boxes on the likes of the 7000 and 7500 series trucks but I dont remember all the details.
I do remember on the on the boxes used on the Ford trucks. Ford had a special inch pound torque wrench. After the box was together and doing the adjustment procedure, they required XX OR MAYBE XXX amount of inch pounds of torque that it required for the steer wheel side of the shaft to go over the high part of the steering gear. The gear is crowned and the center portion has a higher crown cut into it for that purpose.
Maybe see if You can find such info. I do not recall GM having such a process but I liked the way Ford set theirs up and IIRC, I carried that procedure over to any steer box that I rebuilt.

 

[Will L.]

Today I ventured out to the pick a part yard and found a unmolested GM large bore steering gear box for the 95. it still had the GM sticker on it with the part number, but it pealed off when I power washed it. GM part number 26068771.

I cleaned it up and flushed out the fluid that was in it on the bench. tried to feel the gear lash play by holding the steering shaft pinion in place while applying pressure on the pitman shaft pinion. there was a little play but as i turned the steering pinion in different positions and re-checking, the play was the same, left lock, center, and right lock. unlike I remember how the box is that is on my truck now. gets stiff in the center and then sloppy the further out to left or right lock. spinning it back n fourth felt smooth and moved with ease.

I am reluctant to even attempt opening it up for a rebuild and leaning more towards just installing it as is and see what it does and if my steering gets any better.

If you aren’t 100% in confidence on rebuilding it- your labor of removing and reinstalling later is all you risk by installing it now. That is, so long as there is zero contamination in it that can wash into the brake booster.

How to wash it out to ensure it’s clean of debris like metal shavings or anything- all I can guess is wasting a bunch of atf. Install it but have the supply hose hooked up from pump, then have return hose go into a bucket. Have someone turning wheel back and forth before installing pitman arm so it’s easy. Meanwhile you keep pouring in atf to the pump for flushing the box.
After you feel enough has went through and there is no contamination- all should be good.
Not sure what a bucket of regular hydraulic oil cost nowdays- but it’s clear. You could just run that through and see anything that comes out. But not sure if you have a use for the oil afterwards. iirc, you spin wrenches for a living. If done on heavy equipment this is usually easy because you can get hydro fluid, use it, filter it and dump 5 gallons back into a 500 gallon system somewhere and it’s easy peazy.
If you work frequently with a transmission shop- you can get used atf from them, run it through a fuel filter with an old pump laying around and at 5 microns or under- nothing there to hurt your steering pump or the box.

Imo run what you bought. Why assume it needs fixing unless you see details indicating a problem. Many trucks hit the junkyard with good steering boxes.

I would ask you to document and show differences in the two boxes while both are out so others learn them.

 

[dbrannon79]

If you aren’t 100% in confidence on rebuilding it- your labor of removing and reinstalling later is all you risk by installing it now. That is, so long as there is zero contamination in it that can wash into the brake booster.

How to wash it out to ensure it’s clean of debris like metal shavings or anything- all I can guess is wasting a bunch of atf. Install it but have the supply hose hooked up from pump, then have return hose go into a bucket. Have someone turning wheel back and forth before installing pitman arm so it’s easy. Meanwhile you keep pouring in atf to the pump for flushing the box.
After you feel enough has went through and there is no contamination- all should be good.
Not sure what a bucket of regular hydraulic oil cost nowdays- but it’s clear. You could just run that through and see anything that comes out. But not sure if you have a use for the oil afterwards. iirc, you spin wrenches for a living. If done on heavy equipment this is usually easy because you can get hydro fluid, use it, filter it and dump 5 gallons back into a 500 gallon system somewhere and it’s easy peazy.
If you work frequently with a transmission shop- you can get used atf from them, run it through a fuel filter with an old pump laying around and at 5 microns or under- nothing there to hurt your steering pump or the box.

Imo run what you bought. Why assume it needs fixing unless you see details indicating a problem. Many trucks hit the junkyard with good steering boxes.

I would ask you to document and show differences in the two boxes while both are out so others learn them.

I missed your post before I installed it.

after spending most of the day with my daughter and her hubby, I returned home going to work on this one.

I did flush what I could on the bench feeding it fresh fluid, the fluid that was in it was red atf. looked bright red so I wasn't too worried about debris contamination.

I didn't do any pictures comparing the two, but I did sit them side by side looking at them. both were identically the same, fitting and end cap size (what I look for determining large and small bore) both the pitman and steering shaft splines were in good shape. the only differences I saw were the steering shaft on this one has the little titty sticking out where the old one didn't ( I'm a fan of those btw lol) , the old one had DELPHI on the casing where the new one was stamped with the GM numbers. No paint on it ether, after I had washed all the road grime off, it was a clean rusty metal look other than the aluminum end cap and the sector shaft end cap. both units have the same 3 rotations lock to lock.

it was a breeze to install, one everything on the truck plus this new (used) box was all clean and mostly oil free, two I'm getting used to changing parts 3-4 times on this truck before it works like it should HAHA.

After I got it all buttoned up, topped off the PS fluid. cranked the engine for about 2 seconds not wanting to starve the pump. topped it off again then tried rotating the wheel. it steered like it just got a new part installed! But...

I apparently traded one problem for another. LOL it's what I get I suppose.

after picking up all the tools and doing a final top off on the fluid I took it out for a test drive.

The responsive seems to have gotten better though I still have play in the steering wheel. I can move the wheel from about 11 o-clock to almost 1 o-clock before the tires feel like they respond. This must be the small amount of play I felt in the box while I had it on the bench.

The good part is the truck no longer feels like it's darting back n fourth on the road acting like there is no "center" to the wheel. the truck stays straight other than the little play I get in the wheel as I turn or correct the steering. I'm not having to constantly over correct to keep the truck in it's lane.

the above issues I can deal with, having some play in the wheel is fine and I can be satisfied with that so long as there isn't anything else to worry about.

As i make a right turn there is a shuttering sound accompanied with a vibrating feeling in the steering wheel when I turn to the right slowly. turning quickly it's fine.

I stopped and got out checking the fluid which I found to be somewhat frothly. also had my wife turn the wheel while I stuck my nose under the hood. the sound and vibrations are coming from the new box and can be really felt with my hand on the pressure hose to the box.

when I was installing the hoses, I had an issue with the o-ring on the pressure hose and had to replace it. the old one was mushroomed out.

There is also a check valve in the return port on both boxes. I am curious if the check valve is fluttering making this happen. the noise and vibration does not effect how easy or stiff the wheel turns.

I will try to do some searching on this and how the check valve works while I leave the truck sit over night and see if the "froth" in the fluid is simply air that needs to be left alone to go away. Then drive it a few days for work and see if it goes away.

Only other thing I can think of is if the o-ring on the return hose also is bad and now is sucking in air. if that's the case I need to go get me some new o-rings for both connections.

 

[dbrannon79]

I found this while searching about the check valve. they are saying it's in the pressure port. maybe I looked at the box wrong and it's in the pressure port not the return. this I wonder if it's the source of the noise. This link gives me an idea of how to remove and maybe swap the valves between this box and the one I just pulled out. i will check the o-rings first though. I took the truck back out this evening for dinner. It was making the same groan with vibrations in the wheel on right turns only. when I returned home I popped the hood and checked the fluid only to find it was full and was no longer frothy like it was full of air. not being full of air says the system is not sucking air in but still has some sort of issue.

Easy Power Steering Box Check Valve Removal (with Photos)

www.camaros.net

 

[MrMarty51]

Okay, one thing is amiss.
I think that the return hose going back to the pump is a free flow system.
It is under what ever pressure is left over after brakes and steering are activated.
There is no suction on that return hose so there is no way that air can enter that system Through the return to pump circuitry.
If there is air intrusion it will have to be through the PS pump front seal.
I just went through all of this on my 1988 Buick centurion, ooops, century. LOL
I believe that You were even the one that confirmed that it had to be the PS pump creating air intrusion that made the pump groan, creak and create foamy fluid.
The newly remanned PS pump cured that problem, thus far, but, it has been only since yesterday early afternoon that I got that job accomplished and it seems that Vicki has kept it moving quite a bit since I finished it.
I’ll get a chance tomorrow to see how it is pumping. Go to the bank, create a new checking account so I have a place for my pay checks to land, where only I can write checks to cover that I want.

 

[dbrannon79]

I will double check but after the last trip last night the foamy fluid went away but the groan and vibration feeling in the wheel while turning right is still present. turning left and then back to center performs perfectly fine.

I will check this check valve and possibly go as far as pulling the steering shaft and internal valving in the box seeing if it might be bypassing internally. otherwise it will be back to the JY for another box. this time I did purchase their 40 day warranty so I can exchange it free of charge if I need to.

 

[dbrannon79]

Well this afternoon I pulled out the fittings from the gear box checked the o-rings on them. then went for looking at the check valve. ended up pulling it out of the box. it was easier than expected plus I didn't damage it so if I need to, I can put it back.

replaced the o-rings on both hose fittings with new ones and installed them. topped off the fluid and tried it.

it seems to steer easier now without the check valve there. the noise it was making is now diminished to to point that now when I turn the wheel to the right I only hear and feel it when I stop turning and let back on it slightly.

I will drive it for a few days and see it this makes any difference, but while I was under there with the engine running, I noticed the pitman shaft was seeping fluid ever so slightly. it dripped once in the 5 minutes I was laying there starring at it. So ether way I will need a seal kit.

if everything pans out after a week or two of driving, I think I will go ahead and order a complete rebuild kit for it, but not touch the piston and BB's like I did on the other one. the only parts I will go though would be the sector shaft bearing, seal, and the orbital valve. if the piston was bypassing I think it would be hard to turn.

 

[MrMarty51]

Buick started groaning some. Added more fluid. Took it to the shop where the guy has a lift. Have him scout out the leak and fixit.

 

[dbrannon79]

I just starting replaying in my mind what all I have done to this steering system and the issues I have had with it back from the beginning.

It all started with a leak.... This was back when I first got the truck, the hydro-boost was leaking fluid into the cab. after replacing it with one from the auto parts, not once, but twice (another leaker) is when all the other problems began.

after the HB it was the pump the bed over how many times it ran empty with the HB leaking. another auto parts rebuild special.. and then again, and after I was fed up with auto parts rebuild specials I harvested one from the JY and threw a seal kit in it.

after that escapade along came the beloved gear box... it too began leaking along with being sloppy. Once again another auto parts rebuild special. That one got real sloppy after a while of driving so it got exchanged for a second auto parts rebuild special.


The above might not have been in that specific order, I think the JY pump was the last thing I did to the steering iirc. but I was having what I think was a fluid overheating issue. would work find for driving here and there, but driving for an hour or so and the steering would get stiffer than it usually was along with almost burning my hand on the steel lines.

one of the last things I did was this past summer I cobbled in a large trans cooler into the PS return lines and mounted it on the inside of the brush guard in front of the grille. this almost completely solved the hot fluid and stiff steering unless I let it sit idling in a parking lot. Then it would have this issue until I went down the road where the cooler lowered the fluid temps.

This leaves me to now with the last gear box that was an auto parts rebuild special which I attempted to rebuild but was junk to begin with.

Now I have introduced a used gear box that was last touched by the GM assembly line and left out to rot in a JY. the only issue I have now I groaning with a steering wheel vibration when turning right.

the classic BIG mistake on my part was getting the A-1 Cardone reman parts from "trusted" auto parts stores in the very beginning. Once a steering system is messed with, it's never the same again...


Ok... (taking a big breath) that was a lot already...

with all that said, I still have the fluid cooking issue that I only put a big band-aid on by adding the trans cooler... Could be any part of the system causing this.

and the whole reason I am messing with it again, to get this thing to drive straight without fighting to stay in one lane, I call it bump steer but it always acted like there was no center. the truck would try veering both left and right, even worse in cross winds.

Now after this new JY steering box, this bump steer feeling is mostly gone other than it does have slop (11o'clock to 1o'clock before tires respond) and this groan accompanied with vibration when turning right only.

@MrMarty51 is right, I might need to look at the pump. But I, unknowingly at the time, introduced so many other issues by installing crud from the auto parts stores along with playing the guessing game going with parts from the JY that everything needs to be replace new or I just suck it up and deal with it LOL.

I think I will drive it as is for the rest of this week. now that the groaning seems to be less than it was I think I might try to make a slight adjustment taking some of the slop out of this gear box, flush the fluid and run fresh ATF with some stop leak for the pitman seal that's seeping ever so slightly. then calling it a day.

With this out of the way I can then make an appointment to take it in to have the suspension fully checked for any other issues making sure it's safe, then get the alignment done.