Delphi 600 Steering Box Tech (Jeep WJ)

[AgitatedPancake]

I'm tearing down an old WJ steering box on the ole trusty yellow workbench for some in depth analysis. From what I understand it's called a "Delphi 600" style. Similar box to a JK , but this is a rear swing where the JK are forward swing. I've heard they have differences around the servo, but I don't have experience with those yet. Looking to discover fluid flow restrictions, see about porting the servo and box itself etc. Starting with just a general teardown and inspection.

*EDIT* Torsion bar diameter is .200". Also check posts #27 and #28 for the continued teardown

I broke the top cap on this one hammering on a pitman arm puller with a really stubborn pitman arm hah

Remove the 4 top cap bolts and the sector shaft pops right out. The distance between bearings is pretty nice on these boxes. The servo housing pops off with 3 bolts of the same thread pitch and length

Servo housing off

Main port that runs the length of the box to the back of the piston. Could probably be upsized with a deep drillbit

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[AgitatedPancake]

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Here's the check ball in the pressure inlet to avoid pressure spikes from backfeeding to the pump

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Found a wire wheel wire lodged hanging out in the incoming pressure port, half way into the servo bore. Interesting, I'm thinking this probably made it's way into the reservoir and passed through the steering pump on the jeep this box came off of. Surprisingly the steering was still working when box was pulled. The oringed connection in the lower left corner feeds the long port in the box to the back of the piston

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Better view of the 4 ports in the servo housing. The closes to the bearing is the return, the next is either L or R (need to check again), the next closest hole is the inlet with the wire hanging out, the closest is the other L/R.

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Quick picture of the servo itself Each section has 4 crossdrilled ports

 

[JR4X]

I can’t see all the pics

 

[AgitatedPancake]

I can’t see all the pics

First pics should be fixed, and here are the rest:


Pull this big snap ring to allow the whole piston and servo assembly to be removed from the box. This ring looks like it's pretty beat up

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Sector shaft bearings

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And here's the piston and servo assembly removed. Next update will be the teardown of the servo itself

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[Provience]

Hmm. Do you see 4 in the first post, and none in the second? I think I know what the problem is, I'll try to fix it now

5 pickture per post limit, looks fixed now

 

[Grendel]

Following along. I don't know a lot about steering boxes.

 

[Wilson]

It would be nice to source a jk box to tear down for a side by side interchange comparison. Assuming that this box is at least very similar to the jk, it’s easy to guess what PSC does to build their super box.

 

[SLOWPOKE693]

My JK box looks just like that, and I'm 99.999% sure its a rear swing box. I'd go look but its raining and I'm not going outside.

Maybe later...

 

[Wilson]

My JK box looks just like that, and I'm 99.999% sure its a rear swing box. I'd go look but its raining and I'm not going outside.

Maybe later...

Jk’s are front swinging, mine is and the jk boxes that I’ve used were.

 

[[memphis]]

Are JK boxes worth a crap to swap in? I’m going completely custom in a willys project. I have a rear swing Toyota steering box that mounts on the outside of the frame but I think my tires are going to rub on it. I purchased this before I learned about JK and WJ boxes because I assumed they were like a yj tj xj. The JK box would get the steering shaft out of the way of the exhaust and be a straight shot to the firewall which is why I grabbed the Toyota box when it came up for sale. If it pukes it will be difficult to rebuild or source... the JKs are abundant and will be filling yards soon enough.

 

[AgitatedPancake]

Honestly I can say durability wise I've had pretty good luck with my WJ box, so if the JK boxes truly are the same I would say they're not a terrible option. I really like the spacing between the bearings on these long sector shaft boxes that put the piston above the frame rail. I still haven't pulled the servo off to see about modding it for more flow, but it's looking promising so far.

 

[Provience]

Honestly I can say durability wise I've had pretty good luck with my WJ box, so if the JK boxes truly are the same I would say they're not a terrible option. I really like the spacing between the bearings on these long sector shaft boxes that put the piston above the frame rail. I still haven't pulled the servo off to see about modding it for more flow, but it's looking promising so far.

i'm still generally of the opinion that you should be porting the WJ box for good flow out to the assist cylinder and choking/throttling/restricting the flow going to the box itself

 

[AgitatedPancake]

i'm still generally of the opinion that you should be porting the WJ box for good flow out to the assist cylinder and choking/throttling/restricting the flow going to the box itself

That's my intent! I want to open the box up to be as free flowing as possible, then handle all the flow control with the valving integrated into the pump as a nice controllable solution

 

[Provience]

That's my intent! I want to open the box up to be as free flowing as possible, then handle all the flow control with the valving integrated into the pump as a nice controllable solution

kinda sorta what I mean. I.E. open up the servo a whole bunch for good glow, but also consider suffocating the flow to the box.

I.E. pump putting out ~5 gpm to the whole unit, Servo opened up to send 5GPM low restriction to the ram, and like a 0.040" hole or something quite small to limit flow going to the box so that all the power is supplied via the ram unless you have a very high restriction, then the box would "add" some assist at that level.

 

[AgitatedPancake]

Ahhh got ya. I still haven't figured out if I'll be able to pull fluid for the ram directly off the servo housing, so the ram is currently limited by the volume the main areas of the box gets. If I can pull fluid directly off the servo housing though, that may work. But would it really effect anything to restrict the box? The box and ram will still receive the same amount of fluid in the same amount of time either way, unless I restrict the box enough to literally slow the box down, in which case the whole system would get slower in turn

 

[Provience]

Ahhh got ya. I still haven't figured out if I'll be able to pull fluid for the ram directly off the servo housing, so the ram is currently limited by the volume the main areas of the box gets. If I can pull fluid directly off the servo housing though, that may work. But would it really effect anything to restrict the box? The box and ram will still receive the same amount of fluid in the same amount of time either way, unless I restrict the box enough to literally slow the box down, in which case the whole system would get slower in turn

that would be the thing i'm most curious for you to try make a removable plug as a stage 1 kind of deal?

literally enough to slow the volume down. like 1 gpm at 1000 psi, then the ram would be "forcing" the steering to move. the ram will generate PLENTY of force and the box piston, being forced via the drag link, will be able to outflow equal volume as it is trying to take in...essentially providing little to no effort similar to a neutered box, but with "some" resistance to avoid the neutered box shimmy. path of least resistance 'should' mean that the volume/flow ratio favors the stronger-ly mounted and stronger-ly force cylinder for faster effective reaction...maybe?

drill it all out, make it fancy and high flow everywhere, turn out a couple of tiny hole "plugs" that you can thread or press in/out of the passages :)

for science and such

edit: biggest tradeoff could potentially be speed for pressure, in my head...which is sometimes on backwards

 

[Wilson]

that would be the thing i'm most curious for you to try make a removable plug as a stage 1 kind of deal?

literally enough to slow the volume down. like 1 gpm at 1000 psi, then the ram would be "forcing" the steering to move. the ram will generate PLENTY of force and the box piston, being forced via the drag link, will be able to outflow equal volume as it is trying to take in...essentially providing little to no effort similar to a neutered box, but with "some" resistance to avoid the neutered box shimmy. path of least resistance 'should' mean that the volume/flow ratio favors the stronger-ly mounted and stronger-ly force cylinder for faster effective reaction...maybe?

drill it all out, make it fancy and high flow everywhere, turn out a couple of tiny hole "plugs" that you can thread or press in/out of the passages :)

for science and such

edit: biggest tradeoff could potentially be speed for pressure, in my head...which is sometimes on backwards

I’ll double check tonight, but I believe that is what PSC does on their JK systems. The servo is a billet piece, with the ram ports directly off of it.

 

[AgitatedPancake]

Hmm I'm going back and forth in my head about that concept. You'd essentially be creating a pressure drop in the steering box. But the steering box is still going to need the same amount of fluid in the same amount of time to flow as fast as the ram. If the ram starts pushing at full pressure and the steering box is still low pressure, are they actually going to be fighting each other? Hmm I need to think on it more

Wilson that's very interesting, I hadn't researched their offerings before so that hadn't even crossed my mind. A billet servo housing is a hell of an idea, and would not be an overly complicated part. due to mostly being just a tight tolerance bore along with some ports and passages.

 

[Fwjeep]

I don’t think using porting size to restrict flow to the piston will work the way you hope. It will restrict both inlet and outlet flow(unless a bypass check valve is used) and it’s starting to get very complicated.
the only real way to reduce ‘Power’ in the attached in box piston is to reduce its size. Or bore if you will.
mad for porting the servo, it’s not easy on these boxes. I figure it’s a shared design with power racks of the same era. The return flow side isn’t as easy to modify as the origanal Saginaw 800 style. There is a good reason PSC replaces the servo with a different style for their assist systems.

 

[Provience]

I don’t think using porting size to restrict flow to the piston will work the way you hope. It will restrict both inlet and outlet flow(unless a bypass check valve is used) and it’s starting to get very complicated.
the only real way to reduce ‘Power’ in the attached in box piston is to reduce its size. Or bore if you will.
mad for porting the servo, it’s not easy on these boxes. I figure it’s a shared design with power racks of the same era. The return flow side isn’t as easy to modify as the origanal Saginaw 800 style. There is a good reason PSC replaces the servo with a different style for their assist systems.

dang

 

[Grendel]

So dumb question, which box is inside the frame rail and forward swing, with the long sector shaft?

 

[arse_sidewards]

So dumb question, which box is inside the frame rail and forward swing, with the long sector shaft?

70s F-series.

Also jeep JK

 

[Wilson]

So dumb question, which box is inside the frame rail and forward swing, with the long sector shaft?

JK

 

[[memphis]]

I have potentially gained access to a “free for now” JK box that I can purchase if it will work for my application :D. Usually this results in a beer trade. I’m excited to see if I can make this work

 

[Fwjeep]

dang

Don’t be discouraged!
the servo might well be enough flow if you bypass the internal piston! Also, the external sweet servo can be a good solution here. The other way to reduce the work the box does, is a larger axle ram, which serves to lower total system pressure required. Just try to stick with the small piston boxes. I haven’t yet had hands on a jl box. They are aluminium, which again, may not be a problem if not using the piston in box .

 

[Provience]

Don’t be discouraged!
the servo might well be enough flow if you bypass the internal piston! Also, the external sweet servo can be a good solution here. The other way to reduce the work the box does, is a larger axle ram, which serves to lower total system pressure required. Just try to stick with the small piston boxes. I haven’t yet had hands on a jl box. They are aluminium, which again, may not be a problem if not using the piston in box .

the goal is to see if it can be reduced flow and reduced power without being totally cut off. keeping it low pressure internally due to the high pressure drop from the tiny piston orifice would "ideally" keep the box from being subject to the explosively high pressure spikes from impacts and keep just enough pressure in there so that it can still somewhat damp the system to avoid shimmy/shake/wobble

 

[AgitatedPancake]

Hmm my conflict there is where you say "reduced flow". The box is still going to need the same amount of fluid to turn the same distance either way, so the only thing being reduced is pressure available at the piston, which (pressure) is free as far as the pump cares, it's flow that counts. Then there is the potential for increased backpressure on the unused side of the piston trying to allow fluid out unless you use a check valve, so I'm just not convinced it would offer any benefit. So far I'm of the mentality that if you're powering the box *and* a ram, give each of them as much as possible.

I finally finished the teardown, so let me give you guys some pictures! I wanted to pull this large disc off just to observe the details around it. The 12 point nut that holts it on is crimped on after being set, and the small crimped area is actually splined to ensure it is never able to unthread itself.

This large diameter slug is what transfers all of the piston force into the housing. The OD sits against a ridge in the housing, then is retained by that large snap ring I pictured earlier that showed serious wear. It's got torrington style flat bearings along with race shims on both sides of the piston for free movement, so the nut was setting the bearing preload

Here it is all apart

That's not related to the servo though, so to remove the servo components you need to remove the roll pin hiding in this hole on the input shaft side

Then it slides apart into 3 pieces

 

[AgitatedPancake]

The piston with the green seals is loose and floating in this pic

All disassembled. The torsion bar measures .200"

 

[AgitatedPancake]

Interesting note, the torsion bar seems to be pressed into that primary shaft, I haven't figured out it's removal yet

 

[Fwjeep]

Picture of the inside bore of the servo ? Return flow pathway I’m interested to see