DE ram with steering box AKA 4500 class steering migration

[HYDRODYNAMIC]

I am still waiting for someone to use a manual rack and pinion as the mechanical gear instead of a traditional 90* manual steering box. Since the gear force is only for feedback and failure control, the rack and pinion can be lighter duty than typical trophy truck and buggy powered rack and pinions. This should open up the ratio to about anything you would want.

 

[HYDRODYNAMIC]

As far as external servos go, I'm very curious about the setup in the woodward catalog. Besides your standard porting in stuff like Saginaw boxes and sweet servos, this one is just flat out huge in comparison. It's got to be able to flow some serious numbers with minimal restriciton, but i haven't heard much discussion about it

http://www.woodwardsteering.com/PDF/10. Power Steering System Components.pdf

This servo looks promising if it is actually larger. I can not tell from the size, but they mention the port as being -8 which looks to be only the return port. That might mean that the other ports are -6 which are not going to flow enough.

 

[JR4X]

I am still waiting for someone to use a manual rack and pinion as the mechanical gear instead of a traditional 90* manual steering box. Since the gear force is only for feedback and failure control, the rack and pinion can be lighter duty than typical trophy truck and buggy powered rack and pinions. This should open up the ratio to about anything you would want.

I hadn’t previously seen any rack’s that were small enough mount to a frame but SXS racks are pretty compact.

 

[AgitatedPancake]

This servo looks promising if it is actually larger. I can not tell from the size, but they mention the port as being -8 which looks to be only the return port. That might mean that the other ports are -6 which are not going to flow enough.

I believe you are correct, -8 return and what I would assume -6 everywhere else. That does seem like the next restriction in the line The servo itself seems physically larger from the image, and the ports are definitely oversized but there really isn't much information out there on this thing. It does have me wondering if it came from some factory application though just for the sake of curiosity. Like what's the largest vehicle you can think of that has hydraulically assisted manual steering? Bus, dump truck, or a full blown semi? It would be cool if we found a big box like that, set up like the delphi with somewhat isolated servo that could be tinkered with.

 

[HYDRODYNAMIC]

I hadn’t previously seen any rack’s that were small enough mount to a frame but SXS racks are pretty compact.

If the travel is too short on the rack. A swing set can be used on the drag link to increase the travel. The swing would be on passenger side frame as far out as possible and the rack would be driver side with a drag link going to the swing. This would also increase wheel travel with a longer panhard bar and drag link.

 

[KrisKYK]

Wouldn't that have a lot of bumps steer on a solid axle?

 

[HYDRODYNAMIC]

I believe you are correct, -8 return and what I would assume -6 everywhere else. That does seem like the next restriction in the line The servo itself seems physically larger from the image, and the ports are definitely oversized but there really isn't much information out there on this thing. It does have me wondering if it came from some factory application though just for the sake of curiosity. Like what's the largest vehicle you can think of that has hydraulically assisted manual steering? Bus, dump truck, or a full blown semi? It would be cool if we found a big box like that, set up like the delphi with somewhat isolated servo that could be tinkered with.

Commercial trucks use a drag link valve which is actuated from a push pull spool valve rather than a torsion. This could be used in place of the drag link.

 

[JR4X]

Still picking and choosing what to migrate. Not enough time to move all the good chat from there to here

It had been mentioned before about possibly running the full trophy truck rack from Howe on a solid axle rig. I completely forgot Shawn and Kevin took off next to the BlueTorch 4500 car at the Every Man Challenge this year. Here is what the two look like side x side. Photo courtesy of ShotsbyTbars4. Found the pic looking for something for somebody else inquiring about our steering. Still got PM's rolling in. Good stuff guys.

 

[Yotota]

Commercial trucks use a drag link valve which is actuated from a push pull spool valve rather than a torsion. This could be used in place of the drag link.

Here we go! Not that I'm certain this would work, but this system is DOT approved and already proven.

You could possibly run a TT/Buggy rack with this style drag link valve between it and the swingset, then a tie rod from the pass side swingset to the driver side steering arm.

​​​​​​​Good find, and I'm sure that between the industrial parts catalogs and truck/heavy equipment parts there are bound to be more solutions out there.

 

[Yotota]

JR4X in general, what's the behavior of your steering like when the pump isn't running? So engine off, lost a belt, blown hose, dead pump, etc. Can you armstrong the steering when needed?

 

[JR4X]

JR4X in general, what's the behavior of your steering like when the pump isn't running? So engine off, lost a belt, blown hose, dead pump, etc. Can you armstrong the steering when needed?

Yes. Last year in the 4400 race at KOH I had ground wire break inside the wire harness at the border of the marine base (where the send an armed puke to come run you off if you get to close) couldn’t get the car running so dad came out and dead towed me back approx 10 miles to the main pit when I had to call it. It steers the same as anything else with no power. Might be a touch more difficult to steer because of the fast ratio but it doesn’t make the vehicle immovable.

 

[JR4X]

So Tim Diekman (timmay) of Liquid Iron Industries built a street able trail buggy using this steering and ran around Moab for EJS for about 2 weeks with it. Timmay wont talk much about it but here are some pics of his Commando buggy. Vetteboy79 got to spend EJS week running around with his TTB buggy with Tim. For the facebookies there are lots of pics of the build. https://www.facebook.com/tim.diekmann.370?fref=ts











And then Timmay pulled it off, sold it and put regular hydro assist on it to put the Jeep up for sale.

 

[JR4X]

We have just completed the second full season on the same parts that were installed on the terminator in 2014. While some in our class are still arguing whether or not the effort is justified others are embracing it having great results like we did. Jimmy's4x4 with has their turn key 4500 buggy package dialed in with a mix of a DE ram and Sweet servo, with a bell crank system so that a triangulated 4 link can be used. No panhard no bump steer no flex steer.




This is Tom More's 1982 Toyota bodied Jimmy's 4500 rig powered by a turbo'd 3RZ Toyota 4 cylinder. Driver Marty Mann drove it to win the Ultra4 nationals at its very first.

 

[JR4X]

As an experiment to see if the integrated servo could work as well as the remote one. I modified a box to simplify packaging. I free floated the piston and welded the ports from the servo to the gear box shut, then ported the servo as big as I could. Installed the same 2 1/2" PSC double ended ram that we put on our original build. The steering works and its powerful, buts its slow. My lock to lock is 2 3/4 turn but the servo in the box restricts flow, even though it's ported. The fittings in and out of the box are -6 an which have 1/4" ID ports. The sweet servo I spec'd out in my original post have -8 ports which are 5/16". The real restriction is the inlet to the steering box because you cant port the check valve that sits right below the HP feed.





This port on the end of the gear box is 7/32. I wanted to cut some round stock and plug the hole then weld over it. I couldn't find any 7/32 stock so I bought a cheap drill bit from walmart and cut the shank off the back. I pounded the plug in and welded the hole shut, then buffed it smooth with a flap wheel on a die grinder. Once I got rolling I forgot to keep taking pics, sorry.








On the other end, the servo end, the port is 1/4 inch. I cut the head off a grade 8 1/4" bolt and cut the threads off so that I had a solid 1/4' plug. Welded it in and ground the weld down with a worn down zip wheel on my die grinder. again no pics but picture these holes welded shut.






You'll notice the scratching in the bottom of the bore in the first pic. My guinea pig box had a sector shaft break a tooth off, then get ground the bits into the bottom of the housing ruining the case. I polished the bore so that the piston without the O-rings moved freely inside knowing that it was already garbage anyway.




On the piston, here I have marked where I made my cuts to disable the piston and "free float" it. I only cut on top and bottom because there is no load placed up or down. I leave the sides alone because the force of the gear teeth pushing away from each other pushes the piston into the side of the case. I also cut the end off where this 3/8 extension would go, so that fluid can travel through the very open recirculated ball area from one end of the piston to the other as well as through the 1/8" wide X 1/8" deep cuts that run the length of the piston.















The cause of the damage that ruined this box, A new shaft was put in its place.

 

[JR4X]

So its done and it works. While it is not as effortless or as fast as V-1 that we put on dads 4531 rig (seriously his is the best of the best) it is a simpler install and is much better than a normal ram assist setup with a powered gear box and tiny assist ram. I'm going to run the next EMC with this modified junker box.













This pic is at full bump and full lock to the right. Its close but clear is clear and I can't imagine the event that I could get it to bottom out at full lock so not concerned. Took the pic to show my dad.

 

[JR4X]

So I'm happy to report that the steering works great. It doesn't beat Version but it beats regular ram assist. In the high speed its awesome, great feed back, return to center, very responsive. Bound up in the rocks it will move the tires just like full hydro. I was able to get it in a situation where I couldn't steer and it broke a tie rod. Ripped the bung out of the tube. I had good penetration on both sides, a steel bung mig welded into chromo seamless, it broke the weld right through the center. It was a pretty easy fix and kept wheeling the rest of the weekend.




















If I was building a new 4500 car from scratch, there is no way I wouldn't use the servo from Howe. It really is worth the money. People keep asking me what Howe does to it that makes it so expensive and I don't know. The original one we put on 4531 has never been removed from the truck since getting installed in 14. I've been asked to take one apart and see what's different inside. Even if I had I haven't seen the inside of what a servo straight from Sweet looks like so I wouldn't know what the difference is anyway. We have a brand new servo still in a sealed box and a brand new PSC turned up TC pump for if and when the first ones quit working. I'm not opening and disassembling brand new parts so that you cheap fawks can figure out how to circumvent PSC and Howe's R&D. I appreciate all the interest though.

 

[JR4X]

Howe has a 4500 class steering out now that uses a 2 inch ram with a custom ported gear box. Howe doesn't organize their website, this is Brian Shultz's 4500 car. He claims it works great and he loves it.

 

[JR4X]

Still working on my setup. I am using a 2.25" 8" stroke PSC ram, AGR MJ steering box that's had the power steering portion of the piston disabled, and a PSC high flow TC pump. I also have a decent sized reservoir and finned cooler with inline filter to keep the system happy. I am not using an external servo like the Sweet unit, I don't think it's necessary at this point.




I opened up the ports on the AGR box to the same size as the -6 hose I use, which I believe is 5/16 or close to it for 100R5 hose. The problem with this is the new openings are HUGE compared to the 1/8" starting hole and it's eating the o-ring and teflon seals on the servo. This is the only drawback for me so far, so I have removed the system and will be going through the box once more to hopefully fool-proof it and smooth out the bores once again to remove any burrs or scarring surfaces.




Anyone else put together one of these with box-only? I've attached a few pics of mine. When it worked, it worked extremely well and I can't see myself going back. I have to get this working properly.

...

 

[JR4X]

Sharing this so as NOT to gloss over the shaking wheels issue. After playing with this for years the shaking almost always has to do with the amount of preload on the mechanical connection. To loose, wheels shaking. To tight, wheels shaking.



[QUOTE="sherm$]

So I guess I spoke too soon maybe I can get some insight. This was working perfect and then just start pulsing/shaking the tires back and forth while steering. Its not consistent so I may get a few turns in that are smooth then it will shake then smooth etc. Still air in the system? Is the .200 too light? Im frustrated to say the least.




Edit to add that it wont shake without the wheels on. Then wheels on but off the ground shakes a little, wheels on the ground and it shakes like its going to break something. Plenty of power. Im thinking maybe the flow mod on the pump was unnecessary. Ill try to find another stock high pressure fitting and try that again.

[/QUOTE]

 

[JR4X]

In other news, I had just about convinced myself that our setup on the original 4531 car was bomb proof. Then at the last race of 4 seasons on this part, Shawn shattered my perception by hitting something hard enough to explode the sweet servo itself. I hope that 4 years of fatigue played a part in this break.

 

[JR4X]

https://i.imgur.com/fOt13J3.jpg[/IMG]

-this needs to be carefully deburred after. I use a grinding stone on a dremmel. Keep going at it until the inner part of the servo fits smoothly and 360* turns. Don’t let the holes get to big; reaching the void between them.

The inlet pressure holes (middle ones) are big enough already.




I’ve seen two styles of inner races. Some with 4 holes for return flow, others with 8

The cross sectional area of both are the same, no need for mods here.

The next most restrictive point is when the return flow travel along the input shaft to the front of the servo. I don’t have a picture of a stock piece here.

This one has been lathed to remove material behind the seal position. So splines-seal surface-piece to be turned down. It’s the area that is in the inner race of the servo. The picture below shows the finished piece. You can notice the reduction of the input shaft, as it goes into the servo. It maintains this diameter right through. After the holes drilled in the servo, this area is the biggest restriction in the box.

Once the fluid comes out of the servo housing(along the shaft) it must exit radially through what I’m calling the seal head. I have seen two different styles in the factory boxes. The left style I have found in factory Jeep Cherokee boxes, the right found in a late model Chevy.

pertinent info

 

[KrisKYK]

Sharing this so as NOT to gloss over the shaking wheels issue. After playing with this for years the shaking almost always has to do with the amount of preload on the mechanical connection. To loose, wheels shaking. To tight, wheels shaking.

Can you elaborate on this a bit more?

 

[JR4X]

https://i.imgur.com/gWYtEDo.jpg[/IMG]

However, the one on the top can be improved.

Remove 1/3 to 1/2 the crests

This double the flow

It may not seem nessary, but this is low pressure return flow, and gains here have huge effects.




-torsion bar needs to be matched to your systems resistance. Core boxes can have many different sizes. Mark the input shaft before you take it apart. It will only work assembled one way. Any other way the box will not be centered, and turn one way as soon as pressure is applied.

These torsion bars can be turned down in lathe. I’ve seen .220 to .175 in factory boxes. The thinner this easily, the easier the steering feel will be.




This end comes factory just press fit.

Weld it. Why not. Label the end with torsion bar size so you never need to take apart again.

All these mods apply to the servo, which is the same in both the external servos, and steering boxes.




Mods to the steering box

-drill the input to the biggest you can fit between the seals. Deburr after. This gets rid of the check valve in the inlet. Run an external pressure relief valve (Howe/psc)

And drill the return as well. This can be made quite a bit bigger

Drill the ‘right’ turn into the usual spot for Saginaw, tapped to 3/8 npt

pertinent info

 

[JR4X]

Part 3 (final)




And weld a fitting to the servo housing for ‘left’ turn. Of course, you will need to drill the hole, 1/4 inch or bigger, depends what you can fit between the seals without getting into the seal area. That box has a hydro fitting cut down and welded. Your going to want too reduce the heat/weld as much as possible. Warping the servo housing is a serious problem. I have gotten away with some, but other boxes seals will fail and leak. Reduce the weld area from what I’ve shown here . This is where psc’s box has good Benefits as it’s cast larger here, and threaded fitting inserted.

I also spent time drilling the port, to the vein along the bottom of the box. It’s difficult to drill, and I’m guessing of limited benefit.

pertinent info

 

[JR4X]

https://www.facebook.com/KrackerFabMotorsports/ Kracker Fab guys got their version of this installed and nailed it first shot. I helped them over the phone but they did all the work themselves. 4600 race Grand Cherokee, first race is KOH next week.

[

 

[JR4X]

Can you elaborate on this a bit more?

Yes, I’ll try. First let’s reiterate, that a servo does not have an output shaft. The steering wheel is connected to the input shaft on one end, and the steering box is connected to the input shaft on the other end. People confuse the end of the servo pointing at the gear box as being an output shaft.

The servo whether it’s integrated in the box or external like we use here only has one job really. It’s trying to balance the hydraulic system to neutral. When the vehicle is sitting still idling and you don’t have your hands on the steering wheel the system is balanced. The spool valve is shut and the servo is bypassing 100% of the fluid from the power steering pump back to the reservoir.

When you put your hand on the steering wheel and turn it just a little bit, the servo senses that there is now an imbalance. The steering wheel input shaft turned, but the steering box input did NOT turn. This discrepancy shuts the bypass and puts hydraulic pressure to the side of the ram that then would turn the steering box input shaft to meet the position of the steering wheel.

When the mechanical connection is to loose, or we have to light of a torsion spring in the servo. You turn the steering wheel with your hand. The servo try’s to move the steering box. The hydraulic fluid moves the steering box input shaft side of the servo to far. So then the servo sends fluid the other direction to turn the steering input the other way. The servo starts bouncing back and forth sending fluid right,left,right,left,right,left trying to find the balance point. Because hydraulics are powerful this shaking is strong enough and violent enough that it can and will break things in a matter of seconds.

This is 100% up to the builder to get right. If it shakes, the feedback from the wheels to the input shaft on the servo is out of whack. My experience begins and ends with Saginaw gear boxes. I’ve never tried anything else. I’ve been able to fix the shakes on the systems I’ve built by dialing in the pre load on the sector shaft, and the input shaft of the gear box. I don’t know how to fix Toyota boxes steering racks or boat cables.

 

[KrisKYK]

Yes, I’ll try. First let’s reiterate, that a servo does not have an output shaft. The steering wheel is connected to the input shaft on one end, and the steering box is connected to the input shaft on the other end. People confuse the end of the servo pointing at the gear box as being an output shaft.

The servo whether it’s integrated in the box or external like we use here only has one job really. It’s trying to balance the hydraulic system to neutral. When the vehicle is sitting still idling and you don’t have your hands on the steering wheel the system is balanced. The spool valve is shut and the servo is bypassing 100% of the fluid from the power steering pump back to the reservoir.

When you put your hand on the steering wheel and turn it just a little bit, the servo senses that there is now an imbalance. The steering wheel input shaft turned, but the steering box input did NOT turn. This discrepancy shuts the bypass and puts hydraulic pressure to the side of the ram that then would turn the steering box input shaft to meet the position of the steering wheel.

When the mechanical connection is to loose, or we have to light of a torsion spring in the servo. You turn the steering wheel with your hand. The servo try’s to move the steering box. The hydraulic fluid moves the steering box input shaft side of the servo to far. So then the servo sends fluid the other direction to turn the steering input the other way. The servo starts bouncing back and forth sending fluid right,left,right,left,right,left trying to find the balance point. Because hydraulics are powerful this shaking is strong enough and violent enough that it can and will break things in a matter of seconds.

This is 100% up to the builder to get right. If it shakes, the feedback from the wheels to the input shaft on the servo is out of whack. My experience begins and ends with Saginaw gear boxes. I’ve never tried anything else. I’ve been able to fix the shakes on the systems I’ve built by dialing in the pre load on the sector shaft, and the input shaft of the gear box. I don’t know how to fix Toyota boxes steering racks or boat cables.

So my take away with from this, is to error on the side of caution and use a higher spring rate torsion bar to start, e.g. to reduce the sensitivity and prevent the unwanted oscillation mentioned above?

Secondly make sure you're steering is set up itight with no backlash or binding...

 

[JR4X]

So my take away with from this, is to error on the side of caution and use a higher spring rate torsion bar to start, e.g. to reduce the sensitivity and prevent the unwanted oscillation mentioned above?

Secondly make sure you're steering is set up itight with no backlash or binding...

Yep, that about sums it up. I run a #200 spring inours and that’s plenty sensitive.

 

[Yotota]

Yep, that about sums it up. I run a #200 spring inours and that’s plenty sensitive.

Random theoretical thought:

It seems like most (all?) automotive PS pumps have built in pressure relief valve, with flow dictated by orifice size.

Could we run the pump WFO for maximum pressure and flow by closing the built in valve, and maximize the output orifice as large as the pump casting can handle? Then follow the pump output with an external pressure gauge and an adjustable pressure relief valve dumping back to the reservoir, followed by an adjustable flow control valve. Then the speed and force of the cylinder could be tuned to match the steering box ratio and the torsion spring in the valve.

 

[AgitatedPancake]

Random theoretical thought:

It seems like most (all?) automotive PS pumps have built in pressure relief valve, with flow dictated by orifice size.

Could we run the pump WFO for maximum pressure and flow by closing the built in valve, and maximize the output orifice as large as the pump casting can handle? Then follow the pump output with an external pressure gauge and an adjustable pressure relief valve dumping back to the reservoir, followed by an adjustable flow control valve. Then the speed and force of the cylinder could be tuned to match the steering box ratio and the torsion spring in the valve.

Some of the top end aftermarket pumps are built without any of the internal relief systems, with the expectation that you will add an external solution there. So you can do external flow and pressure relief with some industrial hydraulic components that already exist. That's not to big of an issue, but realistically just changes the same settings that you can do internally within the pump. The bonus with going external, is you can choose to send all bypassed fluid from either relief action through a filter and cooler before reentering the pump, instead of the pump regurgitating the bypassed fluid as done in factory form.

As I understand it, Internal or external flow/pressure reliefs wouldn't have an effect on the the potential chatter in the system, if it's happening at/near idle. At those lower pump RPMs, you're most likely going to be below your flow cutoff point, and shouldn't be hitting the pressure bypass at least until the chatter begins slamming back and force. But I believe the oscillation would still continue even if you varied your pressure relief.