De-powering the steering rack, plus more to come on rebuilding wrx parts

[Xusia]

For those who - like me - don't understand the finer workings of power steering, I found a series of video (3 parts, all very short) that explain it well:

Part 1

Part 2

Part 3

[freds]

For those who - like me - don't understand the finer workings of power steering, I found a series of video (3 parts, all very short) that explain it well:

Part 1

Part 2

Part 3

Very clear.....Thanks for finding and posting Xusia

[metalmaker12]

Here is video 1 showing the 1/8 play in the 2005-2007 steering rack pinion, shaft. I finally got my computer and go-pro to work here. It was like 7am so don't make to much fun of me

[metalmaker12]

Here is the final outcome. I plug welded some other spots, but in my opinion this is the best option. It was not super clean, since I was in the middle a of a huge side welding job, so the weld is ok, but not my best work, and I had to really monitor the heat input. Prior to welding I dipped the shaft in acetone briefly to try to get some grease out. I also used some degreaser. It got like 90% out, and If I had more time I would have gotten it 100% clean.

Tools: Tig welder, 1/16 sharp tungsten, #6 cup for good gas coverage, 309, or 70s-3 steel wire, and run at about 65-80amps

[RM1SepEx]

Thanks Chris! When I get it back I'll see what I can do to make up a crude fixture and compare forced deflection and rotation when installed in my rack both with the modified piece and with with the stock valve and pinion assembly.

[FFR-ADV]

Thank you for doing this Chris,

Great job!

Steve

[papajon1000]

really appreciate the video.

Thanks

[Xusia]

Totally, thanks!

[longislandwrx]

Send it back to RM1SepEx and see if it fits.! nice jorb.

[metalmaker12]

Thanks guys, it was no biggy, plus I got to learn how to upload my go-pro. I cannot wait to be uploading build videos, and better yet my own 0-60, 80,,,100, 120 and some track stuff down the line etc. I will be doing the 2002-2004 pinion shaft at some point also. I will be sending out the shaft for fitment within a week or two.
Any questions PM me

[Mechie3]

Thanks to a donation from Freds, here is an inside look at the 06 WRX spool valve and pinion assy. Prior to sending it to me he filled it with epoxy. I couldn't get it to move using vicegrips, but longevity is unknown. Seems like it can't hurt to try.

Starting to cut it open. You can see the differences in the two metals. The outside is case hardened, the inside is much softer.


View of the torsion rod. You can calculate angle of twist from TL/JG = Angle (T= torque, L= length, J=2nd polar moment of inertia, G= material strength).


I cut the torsion rod in half to remove the two halves. The torsion bar is pressed into teh lower piece and pinned into the top piece.


There is an accessible pin. You can press this out (start with a short pin so it self supports to start, then use a long pin) and it will unlock the torsion bar. Because of all the epoxy in here, I coldn't get the cut torsion bar half out yet.


The splines. These are located at the bottom. Just under the splin is a thrust journal bearing.


Top half inserted flipped over to show relative positions. There is a small bearing on the inside as well.


The bearing race is indeed part of the spool/pinion body which is why I couldn't press it off and the inside dimenions of the bearing didn't match published ID's for that bearing size. The best way to go is to weld the top like metalmaker did if you're careful and don't warp the bearing race. Another option is to cross drill the assy and press/weld in a pin through the entire assy. A third option is to drill through the middle of the spool valve (remove the upper input shaft first) around the circumference and create spot welds. The last option would be to remove the input shaft, cut off the bearing race portion plus a little extra. Reinsert the input shaft and pin it in place, weld it together, then press a standard bearing over the top (if you can find it in the correct size).

[freds]

Thanks Mechie3...I'm a visual sort of person and am very pleased to see the guts

fred

[longislandwrx]

Looks like the penetration of the epoxy was pretty good. I'm impressed.

Not sure how much force you could apply to this with your hands. I think you'd have a broken wrist before this would fail due to a pothole/curb impact. Repeated vibrations might wear this out eventually but I actually think it might have survived for a while.

[RM1SepEx]

nice work! so the large spline shown in the last photo carries the load and "flops" from edge to edge when you go from left to right etc.. and the relatively little (dia?) torsion bar makes it smoothly transition vs the loose on center flop of the Miata design.

If you can drive out the pin and take it apart and fill that area with the spline with JB weld and reassemble
it should work well...

Metalmaker just sent mine back, I'll see what I can do to set up a test setup to compare stock vs welded

[Mechie3]

I'll have to go measure the torsion bar. It was around 3/16" or so. The epoxy did get rather good penetration. It took me a second to realize it stunk while machining because of the epoxy. To get it out, I had to use a pick and a hammer. Even then, I didn't get it all out, just enough to take it apart. JB weld might be better then epoxy. Not sure how brittle jb weld is when cured vs epoxy since I've only used it once to plug a hole.

[longislandwrx]

So can you press that pin out, separate the sections, glob it up with JB weld/Epoxy insert the shaft and repin? or do you need to mill to get access to that pin?

also is that needle? bearing plastic? could you crack that out, and really get in there with the welder?

[Mechie3]

The needle bearing is some sort of polymer/fiber piece. Looks like a phenolic.

The pin is very accessible, no welding necessary. The only hard part is getting a pin to press out the existing pin to stand up. I used a really short pin so that it could only tip so much. After I pressed it out .125", I got a long pin and finished pressing it out.

Fred just used a syringe to fill it with epoxy and it filled just about every available spot. I don't know if JB weld flows as well as what he used.

[metalmaker12]

Nice to have a machine shop you can use. I knew I should have tried harder with pushing out that pin, but I was set on welding. My way did work, but lets see what we can do to glue one back up and make it hold as long as weld. Nice work Mechie!!

[freds]

I believe JB Weld is epoxy with some powdered metal/steel filler. I bought and looked at it, but it will not flow into the innards of the assembly.

Also, I believe that since every cavity was totally filled with epoxy, even if it "crumbled"...the crumbs would have no where to go. I feel even if you could fill the voids completely with fine grained sand, it would be locked up. There is simply no place to squeeze it to....and what the hey they glue aircraft together with this sort of stuff.

I mentioned to Mechie3 that even if it vaporized and did magically disappear you end up with the "normal slop"...no crisis, and then one could do any of the other suggested ways of locking the unit up.

I have chosen the epoxy injection, which cannot/does not potentially harm the inner race of the bearing (which admittedly is not a normally loaded running bearing)...or potentially weakening the overall concentric sleeves.

I don't think any of the solutions is "bad"...take your pick.

[metalmaker12]

+1 .? I agree, weld, or glue were good

[freds]

+1 .? I agree, weld, or glue were good

Hi mm12, not to be a pain...just to clarify the way I think of it...
Using the epoxy is not really to glue the parts together, but to insert something in-compressible between, particularly, the splines....which eliminates the possibility of there being any "slop". The fact that it will also act as "glue" between all the parts is a bonus.

[metalmaker12]

no pain here, (I meant epoxy) were all 818 brothers learning together and trying to come up with ways to mod stuff. It is all constructive to me. Mechies dissection was a interesting look into the pinion. The epoxy will work well and I understand about it working as a substance that will wedge between the inners of the pinion shaft as well as stick to everything.

[DodgyTim]

I had intended to try the epoxy and measure and post the results seems I have been beaten off the mark...
A normal marine grade epoxy used for boat building has a compressive strength of about 12,300 psi and without much searching I've found other grades up to 15,800 psi.
The big question for me was getting the cavity fully filled, so it acts like a wedge instead of a glue. The sectioned photos are great, now i'm reasonably confident the epoxy solution will work
Thanks for the great work Mechie3

[bnr32jason]

I'm still trying to find a solid answer if the quick steering internals of the JDM Spec-C steering rack will swap into a USDM rack. I've read conflicting information on the internet (as usual).

[JAubin]

Thanks for the research into this Metal and Mechie, both parts that were investigated were 05+ right? Any idea if an '02 rack could use basically the same process?

[freds]

I had intended to try the epoxy and measure and post the results seems I have been beaten off the mark...
A normal marine grade epoxy used for boat building has a compressive strength of about 12,300 psi and without much searching I've found other grades up to 15,800 psi.
The big question for me was getting the cavity fully filled, so it acts like a wedge instead of a glue. The sectioned photos are great, now i'm reasonably confident the epoxy solution will work
Thanks for the great work Mechie3

To fill the voids fully a fairly low viscosity product is necessary.
Since the epoxy, when in-between the splines and filling all spaces, is physically restrained, I reasoned that 3,200 psi compressive strength was adequate. It cannot go anywhere even if its normal compressive stress were to be exceeded.

The one I used in the unit mechie opened, and on my own depowered unit is

http://www.loctiteproducts.com/p/epx...x-5-Minute.htm

It flows pretty well and cures quickly. I injected it into every orifice until it started to come out of other orifices then I kept moving it around as it cured so that none of it could run out before it set-up.

[Mechie3]

Thanks for the research into this Metal and Mechie, both parts that were investigated were 05+ right? Any idea if an '02 rack could use basically the same process?

These are different. They essentially unbolt IIRC. I have one at home I can look at, or I think metalmaker already did one.

[longislandwrx]

I injected it into every orifice until it started to come out of other orifices then I kept moving it around as it cured so that none of it could run out before it set-up.

looking at the pictures, I don't see what hole you used to get this epoxy into the assembly.

[freds]

Valve-Pinion.jpg

Every hole...I mean everyone you can see in this photo, and all those around the pinion that you cannot see, including the holes above (to the right in the pic.)of the bearing....Just don't dribble any into the bearing..ha-ha.
And I held it vertically to be sure the epoxy ran down into the splines..Then kept moving it around to let gravity do its job as it set.

looking at the pictures, I don't see what hole you used to get this epoxy into the assembly.

.

[RM1SepEx]

looking at the pictures, I don't see what hole you used to get this epoxy into the assembly.

he injected it into all of the oil holes that are used to assist the rack to move/turn the wheels... makes very good sense... and he is correct even if it does degrade, where can it go? worst case it finds a way out and you are back to a depowered rack with the slight torsional movement when the torsion bar alows the part to rotate..

I'd just like to see something a bit stronger... however viscosity is key if you inject through the holes.

I'd like someone to try driving out the pin, separate the parts, insert JB Weld into the spline area, put them back together and replace the pin...

Received the welded unit back today... not sure when I'll get to testing it for movement, I've got some honeydoos and a sick dad

[longislandwrx]

Valve-Pinion.jpg

Every hole...I mean everyone you can see in this photo.

Do you have pictures of your other glued one before you put it back together?

[freds]

Do you have pictures of your other glued one before you put it back together?

124 is a photo of the one mechie cut open which shows the epoxy in one particular hole quite clearly. Each and every hole on the one I put back in my assembly looked pretty much just like that.

I masked off the seals and the bearing openings carefully, and cleaned off the tiny amounts of drool that I intentionally caused by injecting in each hole until it started to come out of the other hole(s) Just like greasing a bearing.
...but holding it a little off vertical to make sure the epoxy would run into the splines..as earlier described.
I am quite sure, especially after seeing my guinea pig cut open by mechie, that every void is filled.

20130420_080124.jpg

[metalmaker12]

The epoxy seemed to work well and I do have an 02, but it is fully assembled, maybe I will take it apart.

[freds]

The epoxy seemed to work well and I do have an 02, but it is fully assembled, maybe I will take it apart.

Guys, I forgot to add...I flushed out the insides several times...immersing in gasoline (naughty naughty I know) and blowing it out and then again with Brakleen a few times, blowing out each time...letting the part dry out in the sun for a few hours and only then injecting the epoxy.

fred

[freds]

Deleted

[biknman]

Just my two cents I de-powered my WRX rack doing what the Flying Miata guys did and then added a EPAS Corsa C kit from Don at Rallywiz.com.


http://youtu.be/_5-CyEjIkHU

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[metalmaker12]

I have heard of this unit, but first time I have seen one installed, cool, but how much

[biknman]

I have heard of this unit, but first time I have seen one installed, cool, but how much

The Euro is weak so it was a good deal 325.00Eu shipped which I be live was $415.00USD a month ago.. There are several options:
From [email protected]
Sent: April 11, 2013
you have 2 choices either Corsa B or the Corsa C column. the corsa B is slightly shorter and lighter than the corsa C unit, but the corsa C unit is slightly more powerful than the B as it belongs to a slightly heavier model of car. All kits come with steering column, my unit pre-wired to it, 1 metre of earth wire and 3 metres of wire to go to the master switch/battery. 1 x fuse holder + 50a fuse and very simple instructions. Everything (Apart from the fuse to let you mount it where you like) is pre wired to the loom so you only have 3 wires to connect to get it working. >> Prices are as follows. >> Refurbished corsa C kit: 280 euro plus 65 euro shipping = 345 euro >> Used but fully tested corsa C kit: 260 euro plus 65 euro shipping = 325 euro >> >> Refurbished Corsa B kit: 280 euro plus 65 euro shipping = 345 euro >> Clean used (fully tested) corsa B kit: 270 euro plus 65 euro shipping = 335 euro >> Not so clean but used/tested Corsa B kit:350 Euro plus 65 euro Shipping = 315 Euro >> >> The last units, in case you are wondering why they are cheaper are a batch of units I got in from a breakers yard at a lower price as they are showing signs of rust in a few places, and the breakers cut the wires going from the load sensor to the ECU in error, they are now re-connected, heat-shrinked into place and have gone through rigirous testing so work perfectly fine, but may not look as clean as other units. I can send photos of the units the columns if you are interested. >> Hope this helps, >> Don.

[metalmaker12]

thanks, yeah it is helpful

[Hazelwwp]

Why de-power the steering rack?

The Motor Trend teaser article referenced in Dave's thread says the following ... "On Gingerman’s occasionally ragged track surface, the Factory Five tramlines and hunts out imperfections with an alacrity that is something alarming. Kickback through the steering wheel can be violent."

It also says ... "This isn’t a car for novice drivers."

It seems to me that the power steering may be safer for a young driver. Since I am building this car with/for my teenage son, I want to make it reasonably safe for him to drive. I plan to install the anti-lock brakes, keep the power steering that was on the donor, and perhaps add the Racelogic Traction Control System.