Disclaimer: I am not a steering expert or a mechanic. This is what I did, & I believe it to be correct. I hope it helps someone.
NOTE: This is an IRREVERSIBLE MOD!!
As always, disconnect the negative lead from the battery prior to starting work.
First up you will need to pull the wire from the power steering pump, loosen the belt adjuster & remove the power steering belt. I’m assuming you know how to do this. If not it’s probably not a good idea to proceed any further.
Draining the System.
You’re going to drain the steering fluid from the rack, pump, reservoir & lines so you’ll need a container large enough to hold it. I used the same pan I use when changing oil.
Have the waste container ready. Loosen the spring clip & disconnect the bottom hose from the reservoir & let the fluid drain out. Then disconnect the other hose. You can now remove the reservoir from the car. You won’t be needing it again.
Now place your waste container underneath & disconnect the lines from the steering rack & allow the fluid to completely drain out.
There are 5 brackets holding the fluid lines to the car. Undo these & then unbolt the power steering pump.
Remove all these too. You won’t be needing them either.
Removing the Steering Rack.
First of all, remove the top bolt from the universal joint connecting the steering column to the rack. You may need to spread the collar from around the spline to allow it to separate.
Next job is to disconnect the outer tie-rod ends. You need to loosen the locking nut, and wind it back as far as it will go (1 to 2 cm). Then grab a paint pen & mark the thread, right up against the tie-rod end. That gives you a visual point to stop at when you’re screwing it back in later. Now put a 12mm spanner on the tie-rod & wind it out. Repeat on the other end.
Now remove the spring clips & “twisty wire” clamps from the tie-rod boots, & slide the boots outward to expose the inner tie-rod ends.
It is far easier to loosen these on the car than on the bench. There are 4 steel tabs locking the inner tie-rod end in place. You’ll have to tap them clear with a hammer & screwdriver. The pic above shows this done. Now grab a large shifter & just loosen the inner tie-rod end. Do this on both ends.
Now undo the 4 bolts that hold the rack assembly in place, & remove the rack from the vehicle.
Disassembling the Steering rack.
Now that you have the assembly on the bench, unscrew the inner tie-rod ends from the rack & put them aside.
Loosen the bolt & remove the universal joint & boot from the top of the pinion shaft.
Now to remove the pinion. Towards the bottom of the pinion housing you will see the tension adjusting bolt & locking ring. Loosen the locking ring & remove the tensioner. Inside is a washer, a spring & the sleeve that puts tension onto the rack & pinion. Remove these & set aside in the correct order.
Next remove the cap at the bottom of the pinion. Inside is the retaining nut. Remove this & set both aside.
At the top of the pinion shaft is a dust cap. It simply lifts off to reveal a fair bit of crud & a circlip. Remove this circlip & pull the pinion out. Set it aside for now.
Inside the housing is a bearing that, in my case was easy to remove for cleaning, inspection & re-greasing.
The rack itself is held in place by a spring clip at the opposite end from the pinion. There is a small hole in the side of the housing. You can insert a small flat blade screwdriver through here to lever out the spring clip. Now the rack can be pulled out.
A large sleeve will come out with the rack. Slide it off & set it aside. About half way along the rack is a seal that under normal powered operation, pushes the power steering fluid towards the left or right. This needs to be cut off.
WARNING, THIS IS WHERE IT BECOMES IRREVERSIBLE!!
Now is a good time to give the rack a really good clean up, removing all the old grease & crap from the teeth.
Welding the pinion.
Half way along the pinion shaft is what I will refer to as a “flex Joint”. I don’t know if that is the correct terminology or not, but it’ll do. This joint needs to be welded to eliminate steering play. There is some debate as to whether or not this is necessary, but rather than have to do the job twice, I decided to do it. I will show you where to weld, but I won’t show you my weld because it’s as ugly as a boil on a bum.
But first you need to remove the top bearing & the seals. The top bearing just slides off to reveal a circlip. Remove that & the seals slide off. In the 3rd picture the screwdriver points to the area to be welded. As there will be no more fluid used, the pinion seals are no longer required, but the top bearing is.
Reassembly.
Make sure everything is cleaned, then pack the bearings with new grease.
Also, give the rack & pinion a good coating of grease, making sure it is packed into the teeth.
Slide the rack back into the housing.
There is a seal half way down the housing that can be a pain to push the rack through. Just be patient & don’t force it. It will go through.
Give the large sleeve a coating of grease & push onto the rack & into the housing. Reinstall the spring clip.
Replace the bottom pinion bearing back into the housing.
Refit the circlip to the pinion & slide the top bearing into place. Then push the pinion into the housing. You will need to jiggle it a bit get it to engage with the rack.
Then replace the top circlip & dust cap. Refit the retaining nut to the bottom of the pinion & replace the bottom cap.
Replace the tensioning assembly in the reverse order of removal. Tensioning will come a bit later.
Screw each inner tie-rod back onto the rack, & tighten, then tap the locking tabs back into place (4 each end).
Re-attach the universal joint to the pinion spline.
Centring & Tensioning the Rack & Pinion.
By hand, turn the universal joint until the rack is all the way to one end, counting the number of full turns. Then turn it back half that number of turns. This should have the rack pretty close to centred.
The rack & pinion need to be initially tensioned to 4.8 N*m. Screw in the tensioning bolt without the locking ring to start with. Using a torque wrench, tighten it to 4.8N*m, then back it off about 1/8th of a turn, & tighten the locking ring down. That is a starting point & can be further adjusted as required.
Refit the rubber boots to the tie-rods & secure in place.
You can now refit the assembly to the car. Fit the universal joint to the steering shaft & tighten the bolt. Now position the rack & replace the retaining saddles & tighten the 4 bolts firmly.
Screw the tie-rods back into the outer tie-rod ends, stopping at your paint pen marking, then tighten up the lock nuts.
The holes left by removing the fluid lines can be blocked up with sikaflex, as there is no fluid or pressure build up any more.
Now get a wheel alignment.
Enjoy your new steering.
Sent from my iPhone using Tapatalk
How to de power your NA Steering Rack
Moderators: timk, Stu, zombie, Andrew, -alex, miata
- Gladiator
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How to de power your NA Steering Rack
"I'd rather a bottle in front of me than a frontal lobotomy"
1990 Silver Eunos NA6
1990 Silver Eunos NA6
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Re: How to de power your NA Steering Rack
An alternative method for those without AC:
1) Remove power steering pump drive belt.
2) Enjoy life.
1) Remove power steering pump drive belt.
2) Enjoy life.
WP:1.12.492 SMPN:1.16.403 SMPS:1.05.473 SMPGP:1.53.256 SMPB:2.22.181
- jordan.k
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Re: How to de power your NA Steering Rack
StillIC wrote:An alternative method for those without AC:
1) Remove power steering pump drive belt.
2) Enjoy life.
Wouldn't that be extremely hard to turn because of the fluid still trying to move unpowered ?
A belt snapped on my friends mirage and it was extremely hard to turn as opposed to a factory no PS car.
NA6 Dulux spec
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Re: How to de power your NA Steering Rack
Wow...very detailed write up!
I did it the easy way on my NB - unplug all the lines, turn the steering back and forth to get most of the fluid out, seal all openings.
This meant there was only enough fluid in the rack to keep things lubricated, but not enough to create high resistance.
When I decided I wanted to have PS back, instead of reinstalling everything, I bought a hydro-electric pump off an Astra and had Mania install it. No parasitic drag on the engine, and no problems with power steering fluid boiling if I decided to do an endurance race in the MX5...hydro-electric pump operates at a constant rate, not affected by engine speed!
I did it the easy way on my NB - unplug all the lines, turn the steering back and forth to get most of the fluid out, seal all openings.
This meant there was only enough fluid in the rack to keep things lubricated, but not enough to create high resistance.
When I decided I wanted to have PS back, instead of reinstalling everything, I bought a hydro-electric pump off an Astra and had Mania install it. No parasitic drag on the engine, and no problems with power steering fluid boiling if I decided to do an endurance race in the MX5...hydro-electric pump operates at a constant rate, not affected by engine speed!
- ManiacLachy
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Re: How to de power your NA Steering Rack
Great write up! And it's always good to see Australian Safety Footwear in tutorial pictures
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Re: How to de power your NA Steering Rack
2 x great write up!
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Re: How to de power your NA Steering Rack
ManiacLachy wrote:Great write up! And it's always good to see Australian Safety Footwear in tutorial pictures
That strip of skin between the big & 2nd toes is quite tender, hence it needs the protection of quality Chinese rubber.
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"I'd rather a bottle in front of me than a frontal lobotomy"
1990 Silver Eunos NA6
1990 Silver Eunos NA6
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Re: How to de power your NA Steering Rack
jordan.k wrote:StillIC wrote:An alternative method for those without AC:
1) Remove power steering pump drive belt.
2) Enjoy life.
Wouldn't that be extremely hard to turn because of the fluid still trying to move unpowered ?
A belt snapped on my friends mirage and it was extremely hard to turn as opposed to a factory no PS car.
An advantage of power steering is that it allows the suspension geometry and steering ratios to be optimised for vehicle performance, which otherwise increases steering effort (e.g. fat grippy tyres, more castor, fewer turns lock to lock). Without PS the steering ratios and/or suspension geometry have to be compromised to make steering effort low enough for your grandmother to drive it. If you take a car set up for PS and depower the pump it will require more steering effort than the same non-PSed car. The MX5 PS rack is a quicker ratio than the non-PS rack...hence the reason to depower a PS rack. Otherwise, you'd just use the non-PS rack, right!?
The power steering fluid is free to move through the system if the pump is not powered and does not provide resistance to turning. Don't believe me? Jack up the front of your PSed car with the engine off and turn the steering wheel. It is just as easy to turn as any jacked up non-PSed car.
WP:1.12.492 SMPN:1.16.403 SMPS:1.05.473 SMPGP:1.53.256 SMPB:2.22.181
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