FC steering rack rebuild

[StephenSheppard]

Forgot to mention this earlier but it only matters for assembly not disassembly. See the little roll pin that retains the inner tie rod?



Hit it with a hammer so is fluch like this (Both ends).



Clean all the parts



If it's already clean then don't get cleaners and water in the pinion assembly. Just wipe it down with a clean rag. If any of the holes get plugged or rusty you'll be in a bad spot.



Here's the kit all layed out. For this S4 rack there were two O-rings unused btw.



I repainted the tube after cleaning the assembly. This was drying while I cleaned everything else up. I then took all the tape off and clear coated the pinion housing just for fun.



Here's the rack all cleaned up.



Think gun bore here, needs to be clean, smooth and scratch free for proper operation of the hydraulics. Forgot to mention earlier that when passing towels through this it's just like cleaning a rifle. A very large caliber rifle



Put some new clean power steering fluid in a little cup or whatever you have laying around. I used a bottom of a ice tea bottle after rinsing it out. You will need it to coat some parts for reassembly. I use valvoline power steering fluid almost all the time since it is almost perfectly clear. Makes it easy to know when to flush the steering system out if the color gets darker.





Now for assembly.


The Factory Service Manual (FSM) says to use some tool to drive the washer and seal back into the bore of the tube. I don't have it and you don't need it anyways. Place theseal and washer on the rack like so. Lube it all up with power steering fluid so it's slippery. Not pictured at this time, but you should put the new piston seal on before you do this. It's the light blue seal in te picture of the kit.



Once you get that in there, again use the rack as a slide hammer and drive the washer and seal into the end of the tube. It will make a different noise when it's seated. Also a quick not is to be sure you don't damage the new piston seal when your first aligning the rack in the tube. Even if it makes a mess use as mush power steering fluid as you need to to be sure that seal gets in there correctly. That and the tube seals (The black ones with the green plastic inside pieces) are the ones that do all the fluid sealing in the rack. If they are damaged you will simply have no power steering.

Next install the tube seal and O-ring on the rack bushing and insert it into the tube. Push it down by hand as far as you can, doesn't matter much at this point. Of course lube it up with power steering fluid.



It goes in like this.



Next is the newly cleaned up rack stopper. It goes in like this.



Use the rack stopper to push the rack bushing all the way down till the groove for the wire retainer is visible in the little window like this.



Put the new wire retainer's tail in the hole.



And rotate the rack stopper to feed the wire in.



Get the whole wire in like so.



Then rotate the end 180 degrees so the ends are on the opposite side of the little window.





Now that you have the two tube seals and the piston installed. you can check and see if the assembly will more than likely work when you get it all assembled. If you move the rack back and forth in the tube you should easily hear and feel air being pushed out of one of the hard line ports on the tube when you go in one direction, and out the other in the other direction. You may hear suction as well which is normal. If you don't have that at this point then something is wrong. Disassemble it and figure out what happened before moving on. This doesn't guarantee the rack will work flawlessly, but if it can't do that at least at this point then something is terribly wrong.



The only grease I use for this stuff, axles, joints, or whatever requires grease. again not only is it a good grease it has a very distinct color to start with, so it's easy to know when it's contaminated.

[StephenSheppard]

Pack both side of the bearing with grease. Then drop it in the housing.



Drive the bearing down with a socket that fits the outer edge of the bearing without getting stuck in the housing.



Spin the rack so the "teeth" face away from this hole.



Time to replace all the seals on the control valve assembly.



Slide the plunger off the control valve assembly. Take note of teh direction it goes on. One side has a step and taper.



No picture but remove the O-rings from the plunger and install the new ones, power steering fluid for lubricant.

Remove the four old O-rings from the control valve assembly. Use something sharp like this dope Gerber pocket knife



When you install the new O-rings for the control valve assembly put them on one at a time from the gear side. Install the first one then the second one will pass over the first, then the third will pass over the first and second and so on. Use lots of power steering fluid, take caution these O-rings are not super flexible, don't break them! Patience goes a long way here.



Slide the plunger back on.



A quick side note on the bearing that's on the control valve assembly (The pressed on one) Check it for free play but don't attempt to remove it unless you are replacing it.

Install the new bottom oil seal like this.



Grease it up like this. Don't grease anything above the bottom oil seal. That's powersteering fluidville silly. don't be scared to stuff some grease down in the pinion housing on the roller bearing and all that way down there if you want. You can't really have too much grease.



Stick it in there. tap it with a hammer a couple times to seat it. remember the pinion gear has to mesh with the rack teeth so be sure that's happening before you go hammering around everywhere. You maye need to spin the rack or the pinion or both to get it aligned. It doesn't matter where it starts at. just put it in there.



Should look something like this on the bearing side.



Put the new lock nut on.



Torque it to 22lbft. 17mm btw. use a vise grip to hold the top of teh pinion while torquing. It will be easy, 22lbft is not very tight.



Install the pinion plug. Torque to I think it was 36-50lbft, i went with 45. I also used a bit of red loctite on the threads, since I planned to not restake the aluminium on the housing. If you use loctite you may need to heat teh housing with a propane torch to remove this plug in the future. Or use an impact gun.

[StephenSheppard]

Back at the top of the pinion you should be looking at this.



Install the new top oil seal. I DON'T KNOW IF IT FITS BUT DON'T ACCIDENTALLY INSTALL THE DUST COVER AT THIS POINT! The dust cover does not have metal showing on the top side. Taht's the best description I can give you.



Snap ring is next.



Make sure the snap ring is seated and expanded like this.



Now install the new dust cover.



MOAR Grease!



Grease the rack support too. I mean why not?



I grease the spring just a little so it doesn't bind. Install that in the backside of the rack support.



Next install the yoke plug. you do have to push down a bit while attempting to thread it. Don't cross thread this or your rack and pinion will be trash. Just put it in like a couple turns for now.



See that down in there? Needs grease!



Don't be scared, load that sucker up! Remember you can slide the rack back and forth a couple times and get grease way down in there.




It's important to note that the rack and pinion is divided in three sections as far as lubricants go. The tube: Has powersteering fluid only in it. The aluminium part with the gears and the lower bearing has only grease in it. The aluminium part at the top between the lower and upper oil seals has power steering fluid in it. If there is power steering fluid in teh part where the grease goes then there is something wrong. That's why the two hardlines are external between teh tube and the upper pinion area. To keep power steering fluid where power steering fluid goes and grease where grease goes. Hopefully that will help make sense of this contraption.

I put a little loctite on the lock nut for the yoke plug.



The FSM says to tighten the yoke plug all the way down (14mm btw) and then back it off 25-35 degrees of rotation. Then install the locknut and be sure you hold the yoke plug still at the same time. There's a special tool but a big crescent wrench and a 14mmm wrench will do the job just fine. I actually used channel locks since I couldn't find my big cresent wrench. I know those two pieces on mine look super boot leg. Luckily they face up on FC racks so I can just order them from Mazda new and install them whenever.





SUPER IMPORTANT NOTE FOR DE-POWERING THE RACK GUYS!!!!

That adjustment right there directly effects your steering effort. you can't set it too loose or the rack will eat the housing up but you can loosen it up a little bit. I'm sorry i don't have an angle to give you to back it off to but just play with it on car a bit and see what you like. Basically you don't want to be able to wobble the rack in the housing much at all. If you really grease everything up good you can get away with a bit more than usual. I've done this in the past on Honda racks and had no issue whatsoever even after driving the car for 5+ years.


OK back to the power steering stuff.

[StephenSheppard]

Next i installed the new rack and pinion bushings.



Set the rack in place



Started all the hardware by hand before tightening and of the clamps down on the tube. Then snugged them up.



Here's Aeroquip's part number for the rack output if you want to make it into a -6AN jam like I needed.



That's what it looks like installed. in case it matters :/



Remember the four tiny O-rings in the kit? They go on the factory hardlines. Don't forget to lube them with a bit of power steering fluid.



What it looks like installed.



In my case I have a Small block chevy swap engine cradle, which makes installing the hardlines a challenge to say the least.



Those were fun to tighten lol



Here's my rack input hose thing I had made out of the end of the factory hose. i cut off the hose behind the crimp fitting and ordered a weld on steel -6AN fitting. Needs to be cleaned up still but you get the idea. That threads into the middle hole on the rack. The bottom hole on my unit is plugged (Forgot to get a pic of that). It's super simple I measured the depth of the hole, then cut a bolt at that hieght, just the threaded part and threw the top away. Then I cut a groove across it with a band saw so it can be driven with a screwdriver. Coated the threads in red loctite and screwed it in. Sits flush with the rack. Simple solution. I just use the input and output and ignore the "feedback" hole or whatever it is.


My build thread is in the BAD GUY section

http://www.rotarycarclub.com/rotary_...ad.php?t=16630


THE END.