De-Powering the power steering rack

[Tanj!]

Originally Posted by infernosg

So I understand how to keep the tie rods in the correct location for reinstall (measure, mark, whatever to keep toe settings) but what about actually "centering" the rack (steering wheel is straight = wheels straight)?

Typically one would mark the top of the quill and where it mates to the drive shaft linkage before disassembly to get it all hooked back up basically in the right place. But since we are actually taking apart the rack that doesn't work. You could measure the amount of rack that juts out on each end when quill mark is face up and just reproduce those measurements and mark that as your new up.

Since i'm replacing inner and outer tie rods and updating to a power rack from a manual one and lowering the car I plan on just measuring revolutions from lock to lock and setting it halfway when doing the install and just matching the amount of thread showing for the tie rods between the two sides. I can eyeball it a bit but I already know I'm going to have to go get an alignment done afterwards so I'm not to worried.

[FC3S.USD]

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.

[FC3S.USD]

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.

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

XXX



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

XXX



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.

[FC3S.USD]

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



XXX


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

XXX



Until the whole thing comes out like so







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

[FC3S.USD]

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.

[FC3S.USD]

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

XXX



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


XXX


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


XXX



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.

[FC3S.USD]

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.


xxx




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