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ZJ V8 steering pump, Durango box, and hydroboost?

burntkat

NAXJA Member #1145
Location
Charleston, SC
Question is prety straightforward-

I have procured a ZJ V8 pump and Durango steering box for my 90 XJ. I am going hydroboost braking as well.

Can the ZJ pump handle all of this? I'm looking for folks that have done the research or better yet have actually run this.

The hydroboost unit is from an Astro van. I've got it running in my SAS S10 (though with a 97 Astro PS pump and gearbox, so the matched set) running in that case. They work great. I'd run the Astro pump in the XJ, but it's a "P" pump, where I thin the pump in an XJ is a "TC" type.
 
there are certain years/models of wj pumps that are the higher output to run the hydraulic fan. Those are the ones you want, but i suggest making adjustments to lower the pressure because you'll loose sector shaft seals left and right if you don't. May not be as much of an issue since you're running hydroboost.

I ran a wj pump with a durango box on tons and 37's and it was insanely easy to steer. even easier than my zj with 33's.
 
Well I can't edit the post for some reason. The PS Pump is actually a 2001 WJ 4.7L V8 unit.
 
there are certain years/models of wj pumps that are the higher output to run the hydraulic fan. Those are the ones you want, but i suggest making adjustments to lower the pressure because you'll loose sector shaft seals left and right if you don't. May not be as much of an issue since you're running hydroboost.

I ran a wj pump with a durango box on tons and 37's and it was insanely easy to steer. even easier than my zj with 33's.

Am I correct in understanding that changing out the output fitting to the XJ unit (referring to the new WJ pump here- IE. replace the WJ unit's output fitting with the XJ unit) will address the need to lower pressure?
 
Am I correct in understanding that changing out the output fitting to the XJ unit (referring to the new WJ pump here- IE. replace the WJ unit's output fitting with the XJ unit) will address the need to lower pressure?

something to that effect. there should be plenty of info on it somewhere in this forum, some of it from me. but it's been so long i dont remember. It had something to do with a hole size and/or shimming in that outlet
 
Am I correct in understanding that changing out the output fitting to the XJ unit (referring to the new WJ pump here- IE. replace the WJ unit's output fitting with the XJ unit) will address the need to lower pressure?

Short answer: you need to retain the XJ fitting.
 
Short answer: you need to retain the XJ fitting.

That's the plan. I understand the WJ V8 PSP upgrade involves changing that fitting and otherwise, just bolting it up and capping off the second return (which I won't need to do in this case, as I'll be running the HB return to it).
 
It's a pretty straight forward swap. Only other part you'l have to tweak is one of the bolt mounts need to be tapped or you can just run a bolt through and put a nut on the other side.
 
Correct.

Still and all, my main point is wondering if there's enough volume from the WJ pump to run hydroboost AND steering.

To prevent confusion- hydroboost is a hydraulically-boosted brake booster, instead of vacuum-boosted.

It's what's run on diesel trucks, and gives significantly improved brake performance. I put it on my S10 SAS and was duely impressed. It's going on my XJs if I can find a way to do it without buying a $300 custom pump. To that end, I'm looking at the WJ unit.
 
Correct.

Still and all, my main point is wondering if there's enough volume from the WJ pump to run hydroboost AND steering.

To prevent confusion- hydroboost is a hydraulically-boosted brake booster, instead of vacuum-boosted.

It's what's run on diesel trucks, and gives significantly improved brake performance. I put it on my S10 SAS and was duely impressed. It's going on my XJs if I can find a way to do it without buying a $300 custom pump. To that end, I'm looking at the WJ unit.

I'm sure the hydraulic fan takes way more pump than hydroboost. you'll be fine.
 
Thanks.

It occurs to me I'd probably be wise to keep the outlet fitting on hand just in case it's the bottleneck. I am going to convert to JIC fittings anyway, so it's not a big problem as it would be if I stayed with the OEM pressure line.
 
forget the durango box. they are a waste of time, and hardly an upgrade.

drill and tap your stock box and go with hydraulic assist.
 
Odd you should say this, when it's a widely used upgrade with very few detractors.

You do have to get the proper unit, though. It should be approx 4.25" on the big end, and comes from a 98 V8 non-snowplow Durango.

Drilling and tapping for hydro assist for a mostly street rig is, frankly, stupid. Certainly it's a great way to go for more serious rigs (and in fact I'm working up a system for my S10), but I have a lot of trouble justifying the cost for a vehicle on 31s with 3" of lift that will be a DD.
 
forget the durango box. they are a waste of time, and hardly an upgrade.

drill and tap your stock box and go with hydraulic assist.

you don't know what you're talking about.


however, i probably wouldn't do hydro assist and a durango box. i like a little road feedback.
 
The Durango Box is designed for an IFS front end. it uses bushings where it should use bearings. making it not really an upgrade.

Putting a larger bore box on to get more steering power is the wrong way to go about it. especially with the unibody front end. that's how you crack the uniframe and/or rip your trackbar bracket off. I've been down this road. Large Bore PSC box (same size as durango, but built properly) at no time could I not turn the steering wheel. however, without assist and the tires bound up in the rocks, all of that power is trying to push the rig away from the axle, all of that force is seen by the trackbar, which can and does lead to failure.

assist solves those issues.

if you think hydro assist is overkill for your rig then the OEM box is more than adequate. unless there is something wrong with it, replacing it with a durango box is a waste of time.

are you going to ruin your rig by putting a durango box on it? no.

However, its the first step towards chasing your tail with steering issues.
if you need more steering power and your solution is to go with a durango box, you will also need to upgrade the pump to keep up with the volume. and you should really put a cooler in.

now you're using a box that won't survive as well because it uses bushings on the sector shaft.
And if you are using the rig hard enough to need that extra steering power, eventually you'll kill that box or you'll damage the frame.

then you'll wish you'd done that silly assist upgrade. So you add a ram and tap your box. now you need an even bigger pump to run the large bore box.


oh, and Dan, if you're losing road feeling with assist then you are doing something wrong. :) even with a large bore box the ram should be imperceptible to the driver.

if you don't believe me, you're more than welcome to come drive my rig with a large bore box and assist. I'll even unbolt the ram the first time and you won't be able to tell the difference.
 
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Actually, so was the Astro box I use on my SAS S10. That truck has never steered/driven so well since I put that box on it.

I agree about the cracking issue on the unibody- it should be obvious and I think I mentioned, I will of course be welding the C-Rok reinforcement plate onto it in place of the crappy aluminum spacer that comes with the vehicle stock. This does quite a fine job of taking care of the front end issue, as I've had one on my 90 for about 17 years now.

Trackbar bracket is of course going to be upgraded as well. Since I'm lifting, IMHO, this is one of those "duh, of course you have to do that as well" things. But you're not a mind reader and this isn't common practice, so fair point.

OEM box is leaking, I don't feel like rebuilding it. I could, just don't feel like it. I will be replacing the pump and gearbox at the same time, and doing the wleded-in unibody reinforcement as well.

Cooler is one of the first things I do to any vehicle I buy- the biggest tranny cooler I can fit to it goes downstream of the OEM, and PS cooler goes on the PS return. Both are plate-type, and both get inline filters as well. These are no-brainers, but not everyone does it. Just the smart folks. ;)

Really don't think the bushing is a huge issue.
 
Since I can't seem to edit the thread title and it's leading to some confusion, can one of the mods please edit the thread title and substitute "WJ" for "ZJ" since I was having a brainfart when I typed?
 
The Durango Box is designed for an IFS front end. it uses bushings where it should use bearings. making it not really an upgrade.

Putting a larger bore box on to get more steering power is the wrong way to go about it. especially with the unibody front end. that's how you crack the uniframe and/or rip your trackbar bracket off. I've been down this road. Large Bore PSC box (same size as durango, but built properly) at no time could I not turn the steering wheel. however, without assist and the tires bound up in the rocks, all of that power is trying to push the rig away from the axle, all of that force is seen by the trackbar, which can and does lead to failure.

assist solves those issues.

if you think hydro assist is overkill for your rig then the OEM box is more than adequate. unless there is something wrong with it, replacing it with a durango box is a waste of time.

are you going to ruin your rig by putting a durango box on it? no.

However, its the first step towards chasing your tail with steering issues.
if you need more steering power and your solution is to go with a durango box, you will also need to upgrade the pump to keep up with the volume. and you should really put a cooler in.

now you're using a box that won't survive as well because it uses bushings on the sector shaft.
And if you are using the rig hard enough to need that extra steering power, eventually you'll kill that box or you'll damage the frame.

then you'll wish you'd done that silly assist upgrade. So you add a ram and tap your box. now you need an even bigger pump to run the large bore box.


oh, and Dan, if you're losing road feeling with assist then you are doing something wrong. :) even with a large bore box the ram should be imperceptible to the driver.

if you don't believe me, you're more than welcome to come drive my rig with a large bore box and assist. I'll even unbolt the ram the first time and you won't be able to tell the difference.

Again, you don't know what you're talking about, you just spew shit from the internet. What bushing? My Durango box was identical internally to every zj/xj box i have disassembled, aside from size.
 
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