Delphi 600 Steering Box Tech (Jeep WJ)

[AgitatedPancake]

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

You got it! This is the interesting stuff, and starts to show the finess that would be needed to accurately port one of these without changing other characteristics by getting into other ports or making them open earlier. Some of the ports are drilled at an upward/downward angle so it's not the simplest device

Here are the guts of the servo, the ground grooves in the shaft are the oil passages that open as the torsion bar is twisted

And here's the active half of what those oil grooves do. You'll see 4 important features:
Red - At 12, 3, 6, and 9 oclock you'll see the 4 notches at the outside of the pressed in sleeve, these are the free flowing return ports and have direct access to the full length of those internal grooves
Blue - These larger diameter circular ports inside the grooves are the incoming high pressure fluid from the pump
Yellow - Outgoing pressure to either the L or R side of the steering box (only sees pressurized fluid when the torsion bar is twisted)
Green - Outgoing pressure to either the L or R side of the steering box (only sees pressurized fluid when the torsion bar is twisted)

(Not drawn on version)

 

[Fwjeep]

How much gap is there where the servo barrel mates up with the torsion bar/worm gear. Will fluid go between ?

 

[AgitatedPancake]

Are you talking about the bore diameters? They're machined to be a pretty tight fit without being a press fit. Actually have no seals between them, so they must bypass only a minimal amount of fluid compared to the volume actually being pumped.

I've been thinking more about how to port this assembly efficiently, it would be pretty hard to do with hand tools. But actually having one CNC cut with additional ports would probably actually be pretty cheap. Probably do a 2 piece like factory with a press in inner sleeve, possibly even reusing a stock inner sleeve to maintain that factory tight tolerance bore. At this point though, I think the first step is getting the assist ports directly into the servo housing to remove restrictions from the ports in the box

 

[Fwjeep]

I am thinking with the return flow slots coming out the back as well, there is a chance of getting the flow out the back too. That would double the return flow. Is there any seals between the piston and back of servo?

 

[AgitatedPancake]

They do pass out both ends of the servo bore, but there is a seal between it and the piston just so the volume pressing on the piston can't free flow out the return side. You bring up a good point though, in theory you should absolutely be able to add an extra return fitting between this black seal and the first green seal, hmm.

 

[Grendel]

Is it strong enough for tow rig duty?

 

[fl0w3n]

 

[YotaAtieToo]

It would be awesome if there was a bolt on servo housing with assist ports. If you developed it for a jk I think it would be a big seller as most assist boxes are $1000+ and a lot of jk guys are scared to drill and tap.

So even a $2-300 servo housing would probably sell.

What are the odds the servo housing is the same for the wj and jk box?

 

[AgitatedPancake]

Haha I got as far as I wanted in the teardown that I was satisfied, but if you have any questions about specific details I'd by happy to take more pics and chit chat more

It would be awesome if there was a bolt on servo housing with assist ports. If you developed it for a jk I think it would be a big seller as most assist boxes are $1000+ and a lot of jk guys are scared to drill and tap.

So even a $2-300 servo housing would probably sell.

What are the odds the servo housing is the same for the wj and jk box?

It's too bad PSC doesn't seem to sell their billet JK servo housings, I agree that does leave a market potential to help the DIY crowd. From what I've gathered I believe the JK and WJ servo housings are different, but haven't actually had both to compare side by side. Even if they're different though, an offering for both would probably be pretty well received.

 

[YotaAtieToo]

Haha I got as far as I wanted in the teardown that I was satisfied, but if you have any questions about specific details I'd by happy to take more pics and chit chat more

To be honest I need to get a better understanding of how a steering box actually works before I go any further.

I really like the idea of Jr's disabled piston with a 2.5x8 ram. Even better if it could be done on a JK box.

Maybe this is the wrong thread? It just seemed like JK steering box tech would be closely related to the Wj box.

It's too bad PSC doesn't seem to sell their billet JK servo housings, I agree that does leave a market potential to help the DIY crowd. From what I've gathered I believe the JK and WJ servo housings are different, but haven't actually had both to compare side by side. Even if they're different though, an offering for both would probably be pretty well received.

I could call and ask, but I can see why they don't when they can sell a $1200 box instead.

Maybe just say I already have a box but stripped the threads on the servo