Pre-Hydro Assist, on the Rubicon Trail - going down Big Sluice.
Rigs Submission-10 by colbyjstephens, on Flickr
First of all, HUGE thanks to Owenst7 for helping me with this.
While I'm sure we don't need another thread on hydro assist, I decided I'd do a write up on exactly how I did mine. When researching hydro prior to doing this, I found the information a bit hard to organize because nobody's single post has all the info needed in it. The "Hydro for under $100" thread has excellent information, and I recommend looking at it, but because that "less than $100" system isn't available anymore, there's a lot of searching to be done to find all the info. So, without further ado....Rigs Submission-10 by colbyjstephens, on Flickr
First of all, HUGE thanks to Owenst7 for helping me with this.
Preface
This thread assumes that you have cross over steering with quality rod ends in good shape, such that hydro isn't a bandaid for a steering system in need of repair. It also assumes that your pitman arm has the same amount of throw as your steering arm, which essentially means that your pitman arm and your steering arm are the same length. If they aren't, the directions for centering your steering may not work quite the same for you.
So, who is hydro assist for?
I decided to do hydro assist to take steering pressure off of my frame. I have a bolt-in steering box brace, and a really clean/not-cracked frame. But, despite the precautions I've taken, turning my 38" tires lock-to-lock while sitting on on dry concrete caused a noticeable amount of frame flex. I like reasonably challenging rock crawling (I.E. the Rubicon Trail), and know that high-traction boulder crawling will augment this issue. Additionally, I hate cranking on the wheel super hard when bound up on boulders, knowing that it's not good for my steering/frame. Nobody wants to have a sheared frame in the middle of the Rubicon, or anywhere, for that matter.
So, if you want to:
- Have more powerful steering
- Protect your frame
- Have no more bump steer (Steering input caused by potholes/bumps/etc.)
- Have a more responsive steering system
Then hydro assist is for you. And, for the $300 or less price tag, it makes for a serious capability/reliability upgrade on the cheap. In fact, it's probably one of the biggest bang-for-buck modifications you can do.
Parts List
I bought all the parts for about $250 (I never really added everything up. Definitely less than $300) You might be able to save a bit of money by having a local hydraulic shop build some hydraulic lines for you.
- DIY4x's steering box end cap. It's the next item up on his lathe, so it'll probably be a couple weeks before I see it.
- DIY4x's ram mounting tabs to weld to the axle tube and tie rod. (call to order, not on his website. $2/ea = $8 for a set)
- The ever popular Surplus Center Ram.
- Three of these 3 foot 3/8" hoses. (one for a trail spare.)
- Two of these 90* 3/8 swivel fittings for the steering box.
- Two of these 90* swivel fittings that adapt my 3/8 hoses to my SAE 6 ram ports.
- Smallest/cheapest universal fluid cooler kit from Napa ($30).
- (2) 3/4" bolts with a shoulder long enough to go through the ram and DIY4x's hydro mount tabs. The shoulder, for me, needed to be 1 7/8" long, so I think I ended up with a 4" bolt or so. This was to keep the threads from receiving any load.
- MasterPro Steering Box Rebuild Kit + Extra 236 O Rings + the input seal/dust cover from a Napa kit. (more on the Napa kit stuff later)
- Astro-Van secondary fluid reservoir connected by radiator hose to the original.
- 3 Quarts P/S fluid.
- A tiny funnel that fits into the end of your hoses.
Note: For a full steering box rebuild kit, including the bearing, try AC Delco 350340 or AC Delco 350440. The difference is the input shaft diameter - so check your box. (Thanks, 4x4High!
)Hydro Install
Centering your steering.
We got super technical on getting my steering aligned and perfectly centered. While this is overkill, I'm really glad we went with ultra precision because of the added level of mental security. You don't want the ram to be putting a ton of force against your steering stops, because that puts undue and potentially catastrophic force on your knuckles.Make sure that your tie rod is giving you proper alignment, between 1/8" to 1/4" toe-in. I'm sure someone will post up some critique of those numbers, but it works for me.
Disconnect the steering shaft from the steering box. This connection is the rag joint. It may be a bit of a challenge if your steering shaft is old and crusty, because you'll need to force it to telescope in on itself to get it off. Sometimes a little persuasion with a hammer at the telescoping joint helps. Some folks use heat at that joint as well.
Next, remove your steering stops and check to see that you're getting exactly the same amount of turning radius on each side, and that your total steering change from one lock to the other is more than 8". Don't forget to reinstall the steering stops when you're done with the install!! You don't want that ram putting massive force on your knuckles because the steering stops stop the knuckle from turning while the ram still has force. You can check this using a tape measure from the pumpkin casting to some notable place on your tie-rod. For me that was the seam between the tie rod and the locking nut. Turn the wheels all the way to one side by pushing on the brake rotor, and measure. Then push them all the way to the other side and measure. The difference between these two should be just over 8".
If you're like me, you'll find that one side doesn't throw as far as the other, which means that you need to adjust your drag link until both sides are exactly the same amount of throw.
Find the point that is dead center between your steering arms on your tie rod and mark it with something that's easily visible. Divide the total throw of your steering in half, and use that number to center your steering perfectly. So for example, if it's a total of 8.5" of throw, and the distance between the pumpkin casting an the driver's side measuring point is 31", then subtract 4.25 from 31, and set the steering so that the distance between the pumpkin casting and the measuring point is 26.75". Now you'll know that you know that you know that the steering is perfectly centered, and you'll have a quarter inch more throw than the ram will allow. This tells you that you won't destroy your knuckles over time.
Prep your ram cylinder and install.
If you use the ram that is in the parts list of this thread, you'll need to cut the endcap off of the cylinder side and rotate it 90* and reweld it, if you want your hydraulic fittings to point up and away from obstacles. As it comes, they would face forward and be between your tie rod and the ram. Unless you have offset tie rod ends that give you more distance between the tie rod and the axle tube, you may have to do this just to make it fit. Most guys extend the cylinder (which can require significant force right out of the box because it's not lubed - I used a hi-lift jack and rope) and cut at the seam between the end cap and the cylinder tube. I didn't understand that, and just cut the eye off of the end of the cap. It worked well for me, and I would kind of recommend that way because your welding doesn't have to be as precise - meaning that it doesn't matter if you have a perfectly air tight weld, and you don't have to worry about blowing through the side of the cylinder. It does take some more set up, however, to get the 90* just right.
When welding, wrap the rod-end side of the cylinder in a wet towel to help dissipate heat and prevent it from messing with the seals and such inside. This is much less of a concern if you cut and weld where I did.
Next, bolt your mounting tabs to your ram. Set your ram to dead center. Since the ram I linked you to has 8" of travel, set it to exactly 4". Have a helper hold it in place so you can see where you need to clean your axle tube and tie rod for welding. I used a flap disc for this task. Since the ram has swivel eyes, I put my ram as high as I could on the axle tube and tie rod to keep it from hanging below the tie rod, and thus out of harms way.
Then, have your helper hold it in place while you tack each of the tabs down. You may wish to cover the ram at this point to prevent any slag from sticking to the rod. Then, remove the ram, and take a socket that fits between the tabs and put it in there and clamp it lightly into place with your mounting bolt to prevent unwanted movement/warping while welding. Then finish welding things up. Wait till cool and reinstall the ram.
Installed:
I decided I would rebuild my steering box during this endeavor because my truck has 203,000 miles on it. I'm glad I did because it was full of nasty sludge that was scuffing the internal surfaces of the box. The box rebuild, however, is an optional part of this project.
Option 1: You can simply remove the box from the truck, install the new tapped end-cap and tap either your box or your top cap, and then reinstall. Actually, all of that is possible with the box in the truck too, but a bigger pain in the ass. Please note: NPT taps are tapered - so you don't want to just run them straight through or too far down. Make sure you know how to properly do an NPT tap. If you look up the info on how to tap the side of the box instead of the top cap, you won't have to move the sector shaft which means that you won't need to reset it's location. I'd recommend putting a new 236 O-Ring in the end of the box with your new end cap. Make sure you have a couple on hand in case you screw one up during the install. They fit snug, and it's possible to ruin them as your pressing the new cap in. If you take the top cap off, make sure the top cap seal is in good shape.
Option 2: Buy a remanned box. This option isn't as great as it sounds, however, as there's lots of negative reviews of remanned boxes. Building a box is a complex process, and it's hard to imagine that a company could pay employees a decent hourly rate and still sell them for <$200 and still have the job done well.
Option 3: You can rebuild the whole box and know it's done right with quality parts. But, it's not for the faint hearted. I decided to tap the top cap of my steering box at this time. If you will be rebuilding the box, patiently, slowly, and with MUCH precision, follow the instructions on Pirate. You'll need a pitman arm puller, various picks and punches, seal pullers, etc. Note: putting the new teflon seals in boiling water helps them go into place better without risking breaking/tearing them on install.
Your rebuild kit should come with all the seals you need, less the sector shaft bearing. However, I recommend picking up an extra couple 236 O-Rings, incase you mess up the endcap seal as you're trying to press it into place.
Additionally, later steering boxes (i.e. sometime starting in the late 80s) have a different sized input shaft. The MasterPro kit I linked you to is for the earlier style box, which means that you will either need to reuse the input seal and dust cover, or source them some other way. It happened that Owenst7 had the remains of a NAPA steering rebuild kit that had the proper seals for me, so we mixed and matched. There are two differences between the NAPA kit and the MasterPro kit: The MasterPro kit is half the cost and includes the top cap seal - which I needed because my seal was fubared. Otherwise they're identical.
NOTE: If you tap the top cap - make sure to install your 90* fitting into the cap BEFORE you install your sector shaft.
Finally, reinstall your steering box in the truck with the steering on the box centered, connect the pitman arm/drag link, leaving the steering column shaft disconnected.
P/S Cooler
I bought a tiny universal fluid cooler. It should be plenty for what I need, and minimize the possibility of it cooling too much in the winter. I put my cooler in front of the condenser on the driver's side. I drilled two holes in the core support through which to route my hoses, and took proper precautions to prevent the hoses from wearing through on the core support holes. I'd recommend filling this with fluid after install, and capping the ends to minimize trouble with bleeding the system. the little conical caps from gear oil bottles work great for this.
P/S Pump
I decided I wanted to drill out the orifice of my power steering pump to 5/16" to get more flow (not pressure) at idle. I also decided that since my steering box was full of crud, I'd remove the whole pump and clean it out real nice. You can get the orifice out without removing the pump, but it'll be a bit of a pain. I don't think the pressure modifications are a good idea (For more info on those, search "West Texas Offroad Power Steering Pump Modification" on Google.) With that one modification I have plenty of steering power and flow.
Hydro line install and system bleeding.
Space is getting tight around the steering box with the new lines + the driver's side secondary battery...
Put the fittings into the box and ram loosely without sealant. You should spend some time figuring out the best way to route your hoses. For me, it worked out well to run the driver's side hose between the spring and the frame rail to the fitting on the front of the steering box, which was pointed at about 270* clockwise from vertical. I ran the other hose back under the engine, then through the space between the frame and the spring, then between the frame and the steering shaft (in front of the stock bump stop) to the top of the box, where the fitting was pointed about 340* clockwise from parallel with the frame.
Once you have your fittings aligned on both the ram and the steering box, tighten them down. You'll want to add some sealant to the steering box fittings, as they don't have an o-ring seal on them.
Next, you'll want to prime your lines to minimize the amount of bleeding you'll have to do. Get a tiny funnel that fits into the end of your hoses. Turn the steering all the way in one direction, and put the funnel into the end that is completely closed. Pour a bit of fluid in until the bubbles confirm that the hose itself is full. Then have a helper gently/slowly turn the steering while you are pouring fluid to pull the fluid into the ram. Once that side is full, connect it to your steering box and fill the other hose. On the second hose, there is no need at this point to turn the steering box back the other way.
Connect all the lines to your steering box/pump. Fill the pump with fluid and watch for bubbles. It should mostly fill the box at this time, and really minimize how much bleeding you have to do. Go ahead and add your remote reservoir at this time and fill it too, until no more bubbles surface. I didn't mount mine to my fender until later, so I could hold the remote reservoir as high as possible. You'll have to get creative with how to connect your reservoir to your pump. You might consider some radiator hose with a combination of adapter fittings to allow you to connect several sizes of hose so that it can neck down to the size of the fitting on the Astro Van reservoir (or whatever other reservoir you're using.)
Connect the steering shaft to the box, if you haven't already. With the engine off, truck on jack stands with no tires, and a friend to help keep the fluid full, cycle the steering lock to lock until no more bubbles appear. This took me probably no more than 20 turns (10 each direction). Then, fire up your engine and do it some more. You probably won't have many bubbles to deal with at this point. It only took me another 10 turns or so to finish the job with the engine on.
I mounted my remote reservoir to the driver's side fender under the hinge, and it just barely clears. If you don't have a driver's side battery, the core support might be a better location, but it was just too tight of a fit with the direction that the nipple comes off of the Astro Van reservoir. Tomorrow a PSC reservoir comes in the mail to me (Thanks, Russell!
), and I'm going to see if it will fit better there.Remote Reservoir mounted:
IMG_20130625_081740_448 by colbyjstephens, on Flickr
Tight clearance of the reservoir:
IMG_20130624_114600_336 by colbyjstephens, on Flickr
First Impressions.
I've only driven it about 3 miles, but it's AMAZING - but, it's kind of strange too! Because of the ram I don't feel the road in the same way - it's kind of like driving a fork lift with fully hydraulic steering in the sense that you don't feel any input from the road (which is good, but different from what I've been used to!). It also significantly increased the sensitivity of my steering as well - even a tiny input from my hand gets the wheels turning. I can turn the wheels lock to lock with one finger on concrete.
The End.
That's it, I think! If I think of something I missed, I will add it to this post to make the post more complete, and will also reply to the thread with the info to let subscribers know that something changed.
Again, HUGE thanks to Owenst7!
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