ADVICE ON STEERING BOX SPOOL VALVE

[Ross Wooldridge]

Hey all,

I need some advice and suggestions please... here's the back story:

On my 66 T&C I recently had the steering box and pump rebuilt because the fluid was pouring out faster than I could pour it in, and with 300,000 miles plus on the car, it was time.

When I got both items back from the rebuilder, I installed them and proceeded to drive the car. I noticed that I still seemed to have less than perfect performance - sometimes the pressure relief valve would pop off when turning the car around in my driveway (low rpm and speed), and I could feel the pump buzzing through the wheel the odd time, like on an on-ramp. Very rarely it would be jerky, say when turning at an intersection. I attempted to bleed the air from the system, but it never seemed to improve, and in fact, the problem seemed to get worse as the days wore on. I wasn't overly thrilled, but hoped things would settle in.

Well, about 2 weeks in, the pump tossed the pulley off in the driveway (at idle fortunately, so it didn't hurt the rad or the fan), so I limped the car into my shop and took the pump off to deliver back to the rebuilder. Sigh...

They put it all back together and tested it all day on their testing machine, and insisted when I picked it up yesterday that it was all good. They weren't sure why the pulley came off...

So this morning I reinstalled the pump - and to my delight, I have power assist only turning left, and none to the right. WTF?!?!?

I have come to the conclusion that it must be the box, and after discussing things with people whose expertise I trust, I believe I need to re and re the spool valve assembly on my steering box and either clean it up or replace it - perhaps some gunk or filings or something has gotten in there after the rebuild process, and gummed up the works.

I am NOT going to take that box out again if I can avoid it (what a PITA job), as I herniated a disc in my neck doing so the last time. If at all possible, I just want to deal with cleaning up or replacing the spool valve.

Any suggestions on what to look for, how to clean it up and ensure that it's going to work properly before I reinstall it and centre the steering?

Cheers, and thanks in advance!

 

[CBODY67]

Hate to hear of those problems, ALL of them!

The spool valve, just as the shuttle valves in the transmission valve body CAN wear with use. I have not idea nor do I recall ever seeing the clearance tolerances, BUT they must exist somewhere, just like bearing clearances on a crankshaft. There ARE places that refurb the valve bodies to return them to factory tolerances!

On the valve itself, you can look for longitudinal wear marks worn into it. IF they re-surfaced it, there should be non-longitudinal "marks" to indicate this, I suspect. IF they just replaced it with a new one, that should be obvious, too, I suspect.

Perhaps a seller of new spool valves can be found whose website might post specs of their new valves so you can compare your valve to those specs, using a digital caliper (from Harbor Freight, or similar, too)?

With a borescope attachment for your phone or a "Critter Cam"-type item from Harbor Freight (or similar), you can look inside of the "bore" of the spool valve to see what it looks like. You can also buy an attachment for your smartphone or computer. Higher resolution is better for this particular look-see operation. You would be looking for indications of machining or un-refurbed wear.

The issues you've had seem flaky, to me. Pulley falling off and no boost in one direction. Totally unexpected.

Local/regional rebuilder in Canada? Just curious.

Please keep us posted on your progress,
CBODY67

 

[MoPar~Man]

Maybe there's air in the system that hasn't been purged yet. You're supposed to turn the wheel several times from lock to lock after an R&R.

Edit: some suggest turning lock to lock up to 10 times, with wheels in the air, engine off, as the best way to purge air. If engine is running, with wheels on the ground, air can / will get whipped up into a froth with the PS fluid and will take a while to separate, possibly have to wait hours or overnight.

 

[Ross Wooldridge]

View attachment 732634

Maybe there's air in the system that hasn't been purged yet. You're supposed to turn the wheel several times from lock to lock after an R&R.

Yes, and I did that a BUNCH the first time, but I think the pressure problem for the right turn side was coming into play at that time because I could never get the pressure relief valve to stop firing off at full lock.

However, this time, the pressure relief valve is not firing off at all...

 

[Ross Wooldridge]

Hate to hear of those problems, ALL of them!

The spool valve, just as the shuttle valves in the transmission valve body CAN wear with use. I have not idea nor do I recall ever seeing the clearance tolerances, BUT they must exist somewhere, just like bearing clearances on a crankshaft. There ARE places that refurb the valve bodies to return them to factory tolerances!

On the valve itself, you can look for longitudinal wear marks worn into it. IF they re-surfaced it, there should be non-longitudinal "marks" to indicate this, I suspect. IF they just replaced it with a new one, that should be obvious, too, I suspect.

Perhaps a seller of new spool valves can be found whose website might post specs of their new valves so you can compare your valve to those specs, using a digital caliper (from Harbor Freight, or similar, too)?

With a borescope attachment for your phone or a "Critter Cam"-type item from Harbor Freight (or similar), you can look inside of the "bore" of the spool valve to see what it looks like. You can also buy an attachment for your smartphone or computer. Higher resolution is better for this particular look-see operation. You would be looking for indications of machining or un-refurbed wear.

The issues you've had seem flaky, to me. Pulley falling off and no boost in one direction. Totally unexpected.

Local/regional rebuilder in Canada? Just curious.

Please keep us posted on your progress,
CBODY67

Yes, local and respected rebuilder - so I wouldn't say that their rebuild practices are sketchy (based on their good track record), but that likely something got overlooked, which happens.

The issue for me is the many hours of labour that I've had to and am having to put into this to rectify what should have been at one time re and re.

Thanks for the advice on what to look for - that will help. I've asked the rebuilder if he has another the valve assembly in case mine is toast.

 

[MoPar~Man]

https://www.chevelles.com/threads/power-steering-only-works-in-one-direction.384395/

Same problem, same circumstances. Problem was resolved - read the last post (#6).

 

[Ross Wooldridge]

Great advice, and I am going to try this before I re and re the valve assembly. Much appreciated!

I will let you know.

 

[Ross Wooldridge]

So - I took the weight of the front wheels, turned the wheel by hand lock to lock several times (engine off), cleaned up the fluid that puked from the pump, then fired up the car to see what might occur.

With the weight off the wheels, easy turning both directions lock to lock.

With the weight ON the wheels, same issue - no assist on the right turn.

 

[Just Carbs]

Was the system performance satisfactory prior to the rebuild with the exception of the fluid leaks?
In other words, was it just fine but leaking?

 

[Ross Wooldridge]

Yes, but there were high miles on it.

 

[Just Carbs]

I'm concerned about the pully coming off, and will there be a repeat performance.

I also think that the burden should be on the rebuilder to diagnose and correct the several problems in situ.
In other words, this should be a drive it in and drop it off and pick it up fixed. Because, it was an all-encompassing system rebuild. I think they own the several problems the system now has. Especially considering that with the exception of the leaking its performance was satisfactory prior to their rebuild.

I rebuild my own steering boxes.
As you know, there's a lot going on in there. The first ABSOLUTLY critical adjustment is the worm shaft string resistance weighting and retaining nut staking procedure. And of course, the all-important reaction spring and seal assembly sequence is also a no tolerance for wrong assembly/parts deal.

The last being the sector shaft and spool adjustment are the least problematic. And the only after the fact corrections that can be made after the box is installed.

Best course of action would be to replace the pump with a known good for an elimination test and go from there. Not easy to do if you don't know a trusted friend that has one handy. Might have to reach out to the community here for that.

If the known good pump don't eliminate all the problems, and it won't, then we're not happy, at all.

 

[Ross Wooldridge]

Agreed -

Pulley was tacked on to prevent it coming off again.

I do think that the rebuilder has some responsibility here - however, the big boss is on holiday until next week. Not sure I can get the car to them - it's fairly far away, and they're not a shop persay, just a rebuild facility. Regardless, it's definitely a discussion I'm going to be having with them once he returns, if I can't get things working myself. I'm keeping him apprised through email as to what's going on, so hopefully that will help.

Something to remember is that steering performance was satisfactory (to a point) when the rebuild was first completed, but was declining until the pump threw the pulley. All evidence at this point still points to a stuck spool valve.

 

[Ross Wooldridge]

@MoPar~Man - I just read your posts within this thread ( Power steering spool valve adjustment ) & watched the video you posted and learned some things.

Question - since everything seems to point to the spool valve being stuck, when I get around to dealing with the spool valve within the valve body, would you remove the whole valve body and then take the spool part out on the bench, or would you remove the spool from the valve body while it's on the steering box?

Cheers!

 

[Just Carbs]

Agreed -

Pulley was tacked on to prevent it coming off again.

I do think that the rebuilder has some responsibility here - however, the big boss is on holiday until next week. Not sure I can get the car to them - it's fairly far away, and they're not a shop persay, just a rebuild facility. Regardless, it's definitely a discussion I'm going to be having with them once he returns, if I can't get things working myself. I'm keeping him apprised through email as to what's going on, so hopefully that will help.

Something to remember is that steering performance was satisfactory (to a point) when the rebuild was first completed, but was declining until the pump threw the pulley. All evidence at this point still points to a stuck spool valve.

Yes, I totally understand the complicated situation. I hope it doesn't prove to be a big major pain in the neck.
There is a fine line between a just good enough and a marvelous steering experience with these Mopar's.

 

[Ross Wooldridge]

Yup - fingers crossed it gets fixed up.

 

[MoPar~Man]

@MoPar~Man - I just read your posts within this thread ( Power steering spool valve adjustment ) & watched the video you posted and learned some things.

Question - since everything seems to point to the spool valve being stuck, when I get around to dealing with the spool valve within the valve body, would you remove the whole valve body and then take the spool part out on the bench, or would you remove the spool from the valve body while it's on the steering box?

Cheers!

I don't think you can pull the spool valve out of the valve body while the body is still bolted to the gear:

The pivot lever will prevent it. The spool valve can be seen through the hole in the second photo. I did take the spool out, after taking the entire valve body off, by removing the outlet housing (the 2 small bolts at the top). I recall things being pretty clean in there, and the spool slides easily even though you can tell it's a close fit.

The PS gear is the one mechanism that you can watch all the theory video's and slide-shows there are about it, and still not know what exactly is causing mine or your particular problem.

Everything depends on fluid that must flow through ports and channels and not be blocked and seals that must seal.

I had a look at a few more PS-gear videos that I did not see before. It seems to me that most of the (Chrysler) tear-down re-assemble video's end without you seeing that the rebuilt gear actually working in the car. There are a lot, a lot more videos about the saginaw box, and it uses a completely different power control mechanism.

Here's a video that I did not see before, back when I was working on my gear:



I didn't solve my problem of squirrelly steering behavior with my original gear (the one shown in these photos). I think I didn't put in one of the reaction rings correctly. So I cheated and swapped in the gear that came bolted to the used stub that went into my Monaco and crossed my fingers. And I totally understand about the physical aspect of handing these units and yes they are an absolute bear to deal with.

What are you using for PS fluid? What did your shop say about that? I'm using ATF+4 and I think it works great. I think it's very important that the oil not froth. You absolutely have to get the air out and keep it out.

I think that any shop that claims to rebuild these things must have a working hydraulic pump setup and must be able to simulate these things working. There's a place here in London that I'm told can rebuild these units, I have it on the backburner in my mind to get in touch and have them R&R this gear, hand them the gasket and rebuild kits that I've acquired from rock, and pick their brains as to what is the secret sauce here. I think this is the place: brakesteeringrebuilders dot com.

Edit: I just watched that video to the end, and something important here: The alignment of the steering shaft to the gear box is important. The entire power steering operation relies on small changes to the forward or backward motion of the input worm shaft as the steering wheel is turned one way or the other. The worm shaft must be free to move forward and backward. I think it's the coupler that allows for this, but there must be room in the coupler for this, so ultimately it's the mounting of the steering column that will determine this.

 

[Ross Wooldridge]

Thanks!

I will remove the entire valve body then, and disassemble it on my bench. I'm nearly positive (in other words, hopeful) that something has gotten in the valve body and is preventing proper movement of the spool.

I use Motomaster Power Steering Fluid, and have for years, with no issues.

The shop I used has a complete testing unit for both pumps and boxes, and the box and pump were working properly after the initial rebuild and reinstallation. However, it's possible that some gunk got disloged and has wound up in the valve body. That's my hope, and that the solution will be a thorough cleaning and or replacement if it's deemed bad.

All hoses, belts and such are new.

If the valve body inspection and cleaning doesn't solve the issue, then I'll be discussing with the rebuilder having the shop of their choice re and re the box. They are an industry leader, and I'm sure will step up to the plate to ensure a happy customer. I have heard about the shop in London, and will keep them in mind for the future if things don't go my way with the current shop.