Power Steering Rack De-Power (or Rebuild)

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Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Sun Jun 24, 2012 9:27 pm

Been having issues with my belt setup using power steering and not wanting to spend a few hundred on a serpentine setup or more on a manual rack with a worse ratio. I already have a 2.7 turn early rack in the car and am not sacrificing that.

I used the following for guidance:

http://www.flyinmiata.com/tech/depower.php

http://www.rx7club.com/showthread.php?t=942543


I'll focus on what's different between the Miata and RX7 rack as the theory behind it is still the same. Also, you can use the pics as a how-to on how to rebuild the rack. Instead of cutting things off, just replace the seals with a cheap rebuild kit. Much cheaper than a reman and these are fairly simple and EASY to remove from the car.

First you need to remove the rack from the car. It's easy. To outer tie rods nuts, remove the inners from the rack with a pipe wrench (keeps alignment), two rack bolts and a triangle-shaped connector at the firewall with a single 10mm bolt. Remove the high pressure line from the pump since chances are it's frozen to the rack and the return line. I had to cut the rubber as it was not coming off the cooler.

With the rack out of the car, start removing lines. I made do with a 7/16" flare wrench which was TIGHT. Assuming they are metric but I liked the bite with the standard wrench better. After the lines are off, be careful because any time you move the rack fluid will shoot out, even when you think it's finally empty.

With the lines out of the way, you need to remove the adjuster. This sets backlash and puts tension on the rack against the pinion:

Image

Don't remove the plug in the center. It will break and seals the rack. I had to make my own at the end and seal with silicone.

Every rack is different and the XR rack was different than the rest of the how-to's I used. The adjuster is around 1 1/8" so came up with this tool. It's backwoods redneck haggard but it worked:

Image

You need A LOT of downpressure, definitely a 2-person job and the hitch ball lets you do that without hurting your hand and someone can turn the top nut. You also need to remove the factory stakes with a chisel or punch so the nut can move. This is by far the hardest part of the entire job.

Adjuster out with the spring inside:

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Everything out:

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And the rack beneath:

Image

Now you need to remove the pinion. Pop the dust cap off:

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Remove the nut while holding the pinion from turning:

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Before you tap the pinion out, on the top of the rack you need to remove the dust cover (mine was broken into 5 pieces already) and the snap ring above the bushing:

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Gently tap the pinion out:

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With the pinion out, you can now remove the rack from the housing. On the passenger side there is a large black bushing with two notches. You can use a large piece of flat stock and turn it. There is a notch in the housing. Turn until you see the wire clip. This needs to be pried out of the housing while you turn:

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Turn until it's fully out and you can unhook it from the bushing:

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The rack needs to come out the passenger side. Turn it in a vice and tap the rack out from the driver's side. I used a long rod that fit into where the inner rack screws in, but small enough diameter to not damage the threads. You need to HIT it, and watch your feet. Having someone either support the rack or give it a soft landing.

Image

Move aside the housing the get the rack in your working area. To de-power the rack properly, you need to cut the seal off the center of the shaft. I used a cut-off wheel on a die grinder and finished with a chisel.

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The actual seals:

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Cut:

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Clean the housing, rack and pinion off (I used brake cleaner) and then greased everything heavily. Assmebly is the reverse of removal. One thing to note, since the seal in the center of the shaft is gone, when you are tapping in the passenger-side bushing DO NOT GO TOO FAR. You need to line the hole for the clip up and there's not easy way to punch it back out unless you have a very large bar to tap it out.

For the fittings, I made a block off plate off the factory line holder and sealed with RTV. For the threaded fittings, I cut the lines flush and welded them closed.

Image

For the adjuster, there's barely any tension on it from the weak spring so you need to stake it. I couldn't get it to stay, even with a couple. I added some 242 Loctite and then put a safety using washers and a screw that used to hold the lines.

Image

To get the wheel centered, I took apart the coupler on the rack at the splined connection. Then with the wheel locked centered, I put the intermediate shaft on the firewall junction and then the rack in. With both wheels straight I connected the splined connection and tightened it.

After moving the pump, I relocated my ground and also made a bracket like factory to hold the lower radiator hose:

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More room!

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Cleaner under car too:

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The car drives like any car with a manual rack. Not too light at high speed and anything over 5mph, even with 215-width sticky street tires is manageable with one hand. Overally, cheaper than buying a manual rack, drives fine, saves weight and clutter and you get to keep a good ratio in the car.
Joe
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Re: Power Steering Rack De-Power (or Rebuild)

Post by DPDISXR4Ti » Tue Jun 26, 2012 9:46 pm

Nicely documented Joe. :thumb

I should point out that this is a TRW rack, and the ZF rack (the one with the "waffle pattern" body), is the more common rack found on the XR, as it was used from mid '86 - '89. I've heard the TRW is easier to work on, dunno if that applies to this "procedure"

I'll move this to the FAQ section eventually.
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Re: Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Wed Jun 27, 2012 9:03 am

Thanks Brad. I wrote it quickly so if you'd like this to head to the FAQ area, I can clean up some of the documentation.


Also, correct. This the early TRW rack from my 12/84 build car. If someone would like to donate a beat ZF rack, I don't mind taking it apart, snapping some pics and seeing what's different.
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Re: Power Steering Rack De-Power (or Rebuild)

Post by wicked93gs » Wed Jun 27, 2012 9:43 am

I have a question...the seal area...it shows you cut out a section of the "seal retainer"(for lack of the proper word) Do you just cut a section out or do you take the collar away entirely? I am very much interested in doing this to my late model rack...I much prefer real manual steering to power steering(much better than looping the lines as well). So what parts would be needed for this? New seals?
'66 Mustang coupe 4.6l DOHC, T45 etc
'77 Celica Liftback GT SRT engine swap/MA5 trans swap
'87 XR4Ti b234f+he351ve+t5 in progress
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Re: Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Wed Jun 27, 2012 10:10 am

wicked93gs wrote:I have a question...the seal area...it shows you cut out a section of the "seal retainer"(for lack of the proper word) Do you just cut a section out or do you take the collar away entirely? I am very much interested in doing this to my late model rack...I much prefer real manual steering to power steering(much better than looping the lines as well). So what parts would be needed for this? New seals?
I cut away the entire seal:

Image


Only part I needed was good grease to lube the gear area and I also did the entire rack so it moved smoothly between the inner seals. You could install new seals (believe Merkur Encyclopedia has the info on the seals needed), but since the rack no longer is pressurized or has any fluid, I don't think it's necessary.
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Re: Power Steering Rack De-Power (or Rebuild)

Post by wicked93gs » Wed Jun 27, 2012 11:29 am

That makes more sense then..it would be nice to get rid of the noisy pump and relocate the alternator there
'66 Mustang coupe 4.6l DOHC, T45 etc
'77 Celica Liftback GT SRT engine swap/MA5 trans swap
'87 XR4Ti b234f+he351ve+t5 in progress
'88 Silver XR4Ti daily driver(Holset HY35, Large NPR FMIC, generic BOV, etc)

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Re: Power Steering Rack De-Power (or Rebuild)

Post by DSPXR4ti » Wed Jun 27, 2012 4:02 pm

I'm going to try this with a ZF rack, that has to be 20 lbs off the left front side of the car works for me.

Hey Joe, Wicked93gs,

Would looping the lines would make the now manual rack hard to turn. Also Joe couldn't you just take the oring off and be done.
Wicked93gs why wouldn't you want the Alternater to the right side of the XR. unless your keeping your A/C.

Ben
85 DSP XR4ti, 2009 Solo 2 National Champion, burns muffler, 3in exhaust, Mc2 Full suspension, 325 hps & 328tqr, GMR Intake, Wilwood brakes, Eaton LSD, stand alone ECU. Working on being SM National Champion.

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Re: Power Steering Rack De-Power (or Rebuild)

Post by John Brennan » Wed Jun 27, 2012 4:16 pm

DSPXR4ti wrote:Wicked93gs why wouldn't you want the Alternater to the right side of the XR. unless your keeping your A/C.
I'm interested in hearing wicked93's response also, but even w/o A/C, keeping it on the driver's side is easier as the wiring is already there, and that side of the engine is cooler. You can get a factory mounting bracket from certain Pintos, although I understand those are kinda' scarce any more.
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Re: Power Steering Rack De-Power (or Rebuild)

Post by wicked93gs » Wed Jun 27, 2012 5:05 pm

Thats pretty much it..I want to keep AC and not having to mess with wiring as much...even without that though I like as little clutter as possible on the turbo side of the engine since I always seem to do more work on that side...in my celica I have the turbo, the alternator, and the starter all on one side...very tight quarters...its horrible to work around...while on the other side I have only the intake manifold...but of course I am amways scraping up my hands working on the turbo side, whether its swapping WGAs, changing a downpipe gasket, playing with alternator or starter wiring...it never fails to be very painful for me
'66 Mustang coupe 4.6l DOHC, T45 etc
'77 Celica Liftback GT SRT engine swap/MA5 trans swap
'87 XR4Ti b234f+he351ve+t5 in progress
'88 Silver XR4Ti daily driver(Holset HY35, Large NPR FMIC, generic BOV, etc)

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Re: Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Wed Jun 27, 2012 5:18 pm

DSPXR4ti wrote:
Would looping the lines would make the now manual rack hard to turn. Also Joe couldn't you just take the oring off and be done.
Ben,

Looping the lines with how I have it setup wouldn't make a difference at all, just would increase clutter. Looping the lines without modifying the rack internally would be harder to steer than what I have.

You could just take the o-ring off,but then all the air from one side to the other has to pass through the small void left by the o-ring, maybe 1/16". Looping the lines might help, but I wouldn't want to test it. While cutting the seal off the shaft turns it into a permanent modification, it's definitely the better way to do it IMO.
Joe
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Re: Power Steering Rack De-Power (or Rebuild)

Post by DSPXR4ti » Wed Jun 27, 2012 5:41 pm

hEaT wrote:
DSPXR4ti wrote:
Would looping the lines would make the now manual rack hard to turn. Also Joe couldn't you just take the oring off and be done.
Ben,

Looping the lines with how I have it setup wouldn't make a difference at all, just would increase clutter. Looping the lines without modifying the rack internally would be harder to steer than what I have.

You could just take the o-ring off,but then all the air from one side to the other has to pass through the small void left by the o-ring, maybe 1/16". Looping the lines might help, but I wouldn't want to test it. While cutting the seal off the shaft turns it into a permanent modification, it's definitely the better way to do it IMO.
Thanks Joe,

I'll be trying in the next week or 2, I have to read the rule book also just make sure I can take thing out of the XR, do that right now. I would be very interested on the feel.

Ben
85 DSP XR4ti, 2009 Solo 2 National Champion, burns muffler, 3in exhaust, Mc2 Full suspension, 325 hps & 328tqr, GMR Intake, Wilwood brakes, Eaton LSD, stand alone ECU. Working on being SM National Champion.

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Re: Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Wed Jun 27, 2012 6:57 pm

Sounds good Ben. I'd you like to wait a week or two, I want to try and get Ray some seat time in the car (street only unfortunately) while I'm in CT and get his opinion. His may be worth more than mine since he can be a better judge of how it will perform at autox.
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Re: Power Steering Rack De-Power (or Rebuild)

Post by pyropete125 » Thu Jun 28, 2012 5:03 pm

looping the lines on our 924S lemons car had no noticeable difference except at standstill. even at a stand still its not hard to turn.

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Re: Power Steering Rack De-Power (or Rebuild)

Post by DSPXR4ti » Thu Jun 28, 2012 5:13 pm

pyropete125 wrote:looping the lines on our 924S lemons car had no noticeable difference except at standstill. even at a stand still its not hard to turn.

pete
Thanks Pete,

For the info, but thats a 924S and it could be different, but just for the weight alone I will be trying this. The rules do say I can removed the PS so I'm going to let Joe and Ray test it out to see how it feels in autocross tirm.

Ben
Last edited by DSPXR4ti on Thu Jun 28, 2012 5:32 pm, edited 1 time in total.
85 DSP XR4ti, 2009 Solo 2 National Champion, burns muffler, 3in exhaust, Mc2 Full suspension, 325 hps & 328tqr, GMR Intake, Wilwood brakes, Eaton LSD, stand alone ECU. Working on being SM National Champion.

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Re: Power Steering Rack De-Power (or Rebuild)

Post by hEaT » Thu Jun 28, 2012 5:30 pm

pyropete125 wrote:looping the lines on our 924S lemons car had no noticeable difference except at standstill. even at a stand still its not hard to turn.

pete
May be true, but then you still have a rack that can leak. And the weight of that fluid and extra line adds up :wink:
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