De-Powering the power steering rack

[TitaniumTT]

I put this write-up on TeamFC3S.Org but since that site has seemed to have died, and there are alot of people here that I didn't know there, I decided to take the time and bring it over here for all to enjoy.

Bill can hopefully chime in on the feel of the steering, seeing as how he was in my car and playing with the steering wheel at DGRR.

So, here we go. (I'm linking the pics so if they don't show up someone please let me know as I still have the originals saved)

There have been NUMEROUS debates about the "right" way to go about this. I have heard people say things from, "Meh, just loop the lines and you'll be fine," to "All you have to do is remove the belt" and I've even heard that it cannot be done I see a few problems with all of the above statements. The seals that make the rack a power rack are still intact and there is going to be a bit a fluid left in the rack that you'll constanly be pushing around. There is no way to avoid this unless you take the time to pull the rack apart, remove all the fluid, and even the seals. See the pic below.



That seal on that shaft is one of the enemies. You can also see on the rack above the two different lines entering the rack. When you turn the wheel you are opening valves that allow fluid under pressure to be pumped into one of the two chambers that this particular seal makes. By leaving that seal intact you are needlessly pumping air and fluid around the rack. This effects the response and overall feel of the rack. If that seal is left in place and you cap the lines, you will constantly be fighting pressure and vaccuum when turning the wheel. You cannot escape physics.

Now, mind you the "feel" is all subjective and alot of people will say looping the lines feels fine but I think the only real way to de-power a power steering rack is to remove everything that makes it power to begin with. Novel idea I know but alot of people don't have the time or the patience or the inclining or the tools to do such a thing and becuase of those reasons I think alot of n00blet type mis-information gets spread around.... So lets get started.

Start with a Powersteering rack. They are identified by the lines... that I already took off damnit. This one happens to be a 15:1 from a parts car that was hit in the passenger front. Subsequently the inner tie rods where both spent.



I may be old but I'm pretty hard-core and luckily I have a friend with a true Manual if I hate this one. Actually I do primarily auto-xing and want to get into some road racing so the tighter the better.

[TitaniumTT]

Clean the sucker up and get it in a vise. I'm not going to drill into my beautiful stainless steel bench to mount a vise. Vises work best, but if you don't have one, clamp it down somehow

I started by removing the outer tie rods and counting the turns on the way out, then labeling them with a sharpie. This was of course before I knew that both inners were toast. I'll save the outers as back-ups and transplant the inner/outter combo from the good rack that I have that will stay power as I don't feel like spending ~$150 on new inner tie rods.

To remove the inner tie rod ends use whatever means available. I didn't have a thin enough wrench. Usually I'm one to go buy a tool and modify it but it was late and almost time for cocktails and we had company coming over. I used a plumbers monkey wrench instead. Hey, at that point I knew they were garbage although they would've been reusable.

HINT: What you may think is an allen set screw or a roll pin isn't. Just turn on the inner tie rods and it will pop out. You WILL damamge ONE thread in doing this but it will be repairable. I guess Mazda's thinking was if you're removing the tie rod it's garbage anyway so why save the thread.

Incidentally. I went to align my car before DGRR, and counting the rotations and measuring everything put my car damn near perfect alignment even after everything, and I mean EVERYTHING including the front subframe was removed at least once.

[TitaniumTT]

Now, starting here, remove in the following order



1) Large Lock nut (not shown)
2) Yoke Plug (center)
3) Spring
4) Rack Support

These are the pieces as they come out of the rack. Left to right following the order above



Moving onto the bottom of the rack remove the Pinion Plug and the locknut. The plug is on the bench and the locknut is still in there under that nasty 20something y.o. grease



Then head over to the top of the rack and start by gently prying loose the dust cap



To expose a lock-ring



A gentle tap at the bottom where the threads are will reveal this engineering masterpiece.



Left to right we have a pair of seals, a bunch of seals, a bearing and again.... a seal...

I hate seals. They are the enemy to all who seek smooth de-powered powersteering racks. They were my enemy. They all fell before me.

[TitaniumTT]

Moving over to the passenger side we'll find the Rack Stopper. This is neat the way they have this retained. I used a piece of 1/8" aluminum stock I had kicking around to rotate the stopper to reveal the catch pin



With a pick you can angle it up ever so slightly and continue to rotate



Until the whole thing comes out like so



Then the stopper will basically fall out when the rack is pushed out.

[TitaniumTT]

Basically every thing that we have removed so far exposing all the enemy seals save one that is still buried in the rack.



This is the real seal that we are after. The other two are bonuses.



With this seal out of the way, and all the fluid removed and replaced with some synthetic grease, there will be virtually no back-pressure, no binding, no sloshing etc etc. It will basically be a fast ratio Manual rack which is exactely what I'm after.

[TitaniumTT]

Now onto the "quill" or the control valve assembly. You can see in this picture that we need to get that myriad of seals off starting with the bearing. I suppose you could just bust out the cutoff wheel and throw bits of fiber and metal into the bearing, but I have a different approach. Seeing as how many of us don't have presses and bearing seperators at our disposal, I found that with that same 1/8 aluminum stock you can place it where the arrow is pointing



Grab onto the oil seals real tight and give the end a few taps to move the bearing slightly towards the rear displaying a REAL PITA lock spring. By moving this spring out of the groove and allowing it to follow the bearing, you can now press the valve/seal assembly to the bearing like so



A few more taps and the bearing along with the lock ring and the valve/seal assembly just falls out. You can see the arrow is pointing to the stupid little lock spring



And finally all the pieces removed. The red arrows are pointing to the lock spring and the grove on the control valve assembly where the f'er rode.

[TitaniumTT]

Now it's time for some welding. The control valve assembly will disengage & rotate slightly to allow fluid to flow. This of course translate to the steering wheel as a few degrees (I've been told ~5*) of pure SLOP. Meaning that you have to rotate the steering wheel 5* for the quill to open and get to it's mechanical limit before the rack will begin to move in or out. I hate slop in racks as much as I hate seals. Time to fix. This pic shows where the break is



So lets weld it up. Even if the weld breaks which I don't think it will, the piece itself will just revert back to its original design. A little ole' MIG welding and viola. Some people will say to TIG it but I don't think it's necessary.



Since I had the MIG out and some copper piping laying around I decided to cut off the connections & plug the holes on the rack since they won't be used again. I know, I'm an OCD ass and this step is totally optional but I kinda like it. PLUS I was planning on painting the damn thing anyway. Either way, you need to plug the lines so that dirt and debris can't get in, and your grease can't get out.



This may be overboard.... nah.... but I can't use the, "Since I had the MIG out excuse," I'll just admit to going overboard, I busted out the TIG and welded up the other holes on the rack,



than sanded everything smooth and painted.



Leave me alone, I'm OCD and I don't have a problem

[TitaniumTT]

So, remember this picture? Now it's time to go after the main seal.



I took the cut off wheel and cut in two places 180* opposite each other and whacked it with a hammer.

DONE

That was main thing to be done.... Yes, that is the big difference between my dfe-powered racks and looping the lines, or plugging them. That seal makes all the difference in the world.

Now with everything ready to be re-assembled, lets look at a few things. On the rack bushing (bottom left 2 blue circles) there are two seals. The one o-ring seal that is visible and an oil seal that is not. Since we are no longer trying to contain all the pressure of a power steering system and only trying to keep some grease in the rack, I took that seal out and removed the spring to allow the rack to slide easier.*

The O-ring you should leave as it will keep the bushing in place. When re-assembling it though, be sure to press the Rack stopper in VERY hard as the end of the rack has two steps and the o-ring needs to compress.

The center blue circles show the other oil seal and the bushing. Same as above I popped the seal out and removed the spring relieveing some of the friction.* The circle on the rack shows where those two seals are located. I used a socket and a bunch of extensions to seal it in place. Worked aight



* I assembled the entire rack and thought that it was a little too stiff to turn. The grease will not lube the shaft as well as the PS fluid. I disassembled and removed the springs inside of the seals. I was really surprised at how mush easier it was to rotate without those springs in the seals. The seals need to stay, but not the springs.

[TitaniumTT]

Lube up your shaft real well



Grease up the quill



Meh, maybe a little much



Put the keeper in place



& after that my hands got REALLY greasy and decided not to touch the camera again. The rest is really the reverse of removal, check the FSM for torque specs and so on.... and enjoy.

-Brian

[NoDOHC]

Awesome! I think I might do this, I hate the slop in the de-power rack too, but it is better than the ultra-slow manual rack.

This seems to be the best of both worlds.

[Rotary#10]

Can we sticky mods?

[Boostmaniac]

Originally Posted by Rotary#10

Can we sticky mods?

I second this.

[Phoenix7]

It's stickied now. Great thread! Don't forget to give good rep points (scale below poster's name) for good threads like this!

[TitaniumTT]

Thanks Phoenix.

So where's Bill? I want him to comment on the feel of this mod as he is to date the only other person on this forum to have felt it even when parked.

Personally, I have no complaints about the feel of it at all. I'm running 235/40 RT-615's in the front and a smaller Sparco steering wheel. This is the 15.2:1 rack so it has the WORST mechanical advantage of all the racks offered for the FC. Yes it is a little difficult when STOPPED. Once rolling it's fine and I one handed her all the way to DGRR and back. There is little effort needed when moving and the response is superb. Me likey and higly rec anyone wanting to do this. I've felt the looped line PS removal and it was kinda notchy. You could feel when the pressure was moving inside the rack. This is seemless, as it should be.

My first Auto-X event is this Sunday........ if I remember to order my helmet. I'll report back then but I can pretty much already tell you I'm not going to have sore arms. I'm not weak by any stretch of the imagination, but I am ~5'10+ and weigh <145lbs.

[WE3RX7]

I'm in the transition part of my moving to my new home so I'm slacking on having an internet connection right now

Brian is on point about the wheel during a stop. I'm of the same build too and I'd say its a two-hander from a DEAD stop, but that may be different when using the stock wheel w/ larger diameter. Go physics. Other than that, I can't see how it would be that bad at all during motion.

I have the same car and the same rack as what Brian used and will be performing this mod myself in the next few weeks. For years I had the rack simply capped off and there is a noticeable difference even for the few minutes of sitting in his car at DGRR. His wheel was very tight, had no real noticeable slop or play. My capped version "pulses" still on full lock... even sitting still if you give it a full turn you can feel the fluid push back which is a little annoying.

Another thing I meant to ask you Brian was if you had any steering angle kit or spacers on the tie rods? I am going to install the SuperNow tie rod kit when I depower my rack and think this may be another thing that'll help "ease" the pain in low speed parking situations.


Any thoughts/opinions on swapping to a depowered 17:1 ratio'd S5 rack? I have an extra one and may depower both and once the car is on the road again interchange them to see which one I like more.