USDM WRX 06-07 rear backing plates + knuckle info

[waren]

rear camber isn't adjustable from the factory on a BD. Can anyone confirm if rear camber is adjustable on a 06 wrx knuckle? (without a aftermarket camber bolt)

would runing an 06 wrx knuckle in the rear create any geometry problems?
Track?
Camber?
Ride height?

I know that complete suspension swaps are possible but it isn't clear if the mix 'n match setup will create issues. There are camber bolt kits that are available for the 06MY wrx so that might suggest that the rear knuckle doesn't have camber adjustment from the factory or it could mean that guys are runing aftermarket bolts to get more adjustment on lowered cars.

[chuckthefuk]

WRX's use front camber bolts or eccentric bolts (1 on each front) the other 6 are just bolts..

Running WRX rear knuckles should not change the track/camber/ride height by that much.

Its the same concept as using 02+ GD suspension in the rear.. it will never be to be spec thats why camber bolts/plates and adjustable links are used to correct the geometry..

If you are looking for a 2-pot rear conversion then these knuckles will make the swap simple and easy.

I can not give info about the ebrake and shoes setup...

-Chuck

[waren]

Thanks chuck. Yes this is for a 2 pot rear conversion.

I could have swore I read a thread somewhere that detailed "factory" camber adjustment in the rear. The only reason I would change the knuckles also would be to gain the factory adjustment. Otherwise I will just pull the hub and then bolt on the backing plates, using the BD knuckles.

Stealership price for the backing plates its $127 each! Gotta love it when both dealerships in town are owned by the same a$$ bandit.

[chuckthefuk]

The BD/GC 1-pot hub does not support the mounting holes for the 2-pot caliper bracket..

The GC STi 2-pot hubs & GD WRX 06-07' 2-pot hubs will work with the 2-pot caliper bracket.

The GC STi axle splines on the hub will fit with the BD splines.. so no axles swaps needed.

Now I CAN NOT confirm if the splines on the 06-07 WRX are compatible with BD splines..

-Chuck

[waren]

hmmm ... I hope you are wrong, cause that wasnt part of my plan.

there are DIY write ups out there stating that all you need is the backing plate from a 06/07 wrx.

http://www.rs25.com/forums/f105/t158653 ... t-way.html (http://www.rs25.com/forums/f105/t158653-2-pot-upgrade-legit-way.html)

The front caliper bolts to the knuckle.
The rear caliper bolt to the backing plate.

So you are saying that the 06/07 backing plate will not bolt to a BD rear knuckle?

http://img35.imageshack.us/img35/8683/subaru09007562l.jpg

https://sl-i.net/FORUM/

[chuckthefuk]

You know I've never seen that kind of write up before.

No one has ever chimed in about swapping backing plates before.

It was always stright to the kartboy/etc brackets to fit the 2-pot.

If that write up is correct then I am going to add this the brake sticky on SLi.

All I was saying was that the 2-Pot caliper bracket will not bolt to a BD hub since the hub has the 1-pot backing plate..

Also again I am not sure if the 06-07 wrx knuckle can support pre-2002 axles.

-Chuck

[waren]

Chuck thanks for updating my post.

From what I have read rear swap requires either (a) or (b) to move the caliper outward for the larger rotor.

a) adapter brackets (kartboy, diy, other)

b) factory 2 pot backing plates (06/07 wrx)

There should be no need for both.

If subaru kept bolt diameter and spacing constant for the 4 bolts (see backing plate in photo above) that attach the backing plate to the knuckle the backing plates will work. From what I have read it is constant for r160 impreza's with 170mm e-brake. All of which have 5x100 hubs.

My plan is to try the backing plates, I am betting on subaru holding to the lego design philosophy. fingers crossed. Unless the wheel bearing diameter changed (for larger STi axles for example) they would not need to change the backing plate bolting.

The only advantage to the adapter brackets is that you do not need to pull the hub off the axle, this may be a selling point for some. For 1st and 2nd gen owners probably time to check the bearings anyway!

The backing plate swap should make everything bolt up with factory parts .... I like factory parts

I will post an update here and a DIY when I am done.

lovin SLi :grin:

[jamal]

Running WRX rear knuckles should not change the track/camber/ride height by that much.

Its the same concept as using 02+ GD suspension in the rear.. it will never be to be spec thats why camber bolts/plates and adjustable links are used to correct the geometry..

it's the same part. no change to alignment or anything. the difference between a gd and bd comes from the lateral links, strut, and strut tower all being a little different.

but yeah, 06 wrx uses 2-pots

[chuckthefuk]

So if thats the case why are there differences between years and chassis variations?
I am just looking for solid facts.. this backing plate business is shocking... how could I have missed this.

GC/BG 96-01 knuckle
http://opposedforces.com/parts/info/28411AA000/

GD 02-05 knuckle
http://opposedforces.com/parts/info/28419FE000/

GD 06-07 knuckle
http://opposedforces.com/parts/info/28419FE001/

unless the above is just variations/revisions..

[jamal]

28419FE001 is a definitely just a revision of 28419FE000

I think the difference between the older upright probably has to do with abs. the sensors and mounting changed over the years and some cars don't even have abs. So, I guess that could end up being an issue, although I hear of people using newer uprights all the time and don't recall anyone saying they had a problem.

Although Subaru does sometimes give a completely different part number to the same part because it is on a different model/chassis.

[chuckthefuk]

Okie dokie..

I'll wait for Waren to finish his 2-pot swap and then add his photos / comments to the brake sticky.

Thanks again Jamal.
-Chuck

[jamal]

If subaru kept bolt diameter and spacing constant for the 4 bolts (see backing plate in photo above) that attach the backing plate to the knuckle the backing plates will work. From what I have read it is constant for r160 impreza's with 170mm e-brake. All of which have 5x100 hubs.


this is definitely, 100%, for sure correct. People were doing the swap to use 2-pots well before brackets were available.

[chuckthefuk]

So I don't get it then..

Why bother with the bracket? Another point of failure..

Is it just the ease of installation that makes people dish out almost the same amount compared to the backing plates?

[waren]

That's my guess Chuck. And if you read any of the install threads using the brackets can be a nightmare! Grinding the backplate to get it too accept the bracket.

It seems you have to pull the hub to get at the backplate bolts. If you don't have a puller and a decent tq wrench ( or maybe don't know ) the brackets are the "easy" route.

I am going to rebuild the calipers first so I won't be installing for a month or so. But I will confirm.

So Jamal, are there any rear uprights/knuckles that had ecentrics for camber adjustment from the factory?

[jamal]

no, there's nothing with rear camber adjustment. I've had a set of aftermarket spc bolts for like 5 years now with no problems. Just set them max negative and make sure the tab is in the right place. On my sti struts that works out to -1.1 degrees.

And yes, to swap backing plates you have to take apart the parking brake and pull the hub. Then you either need the oem service tool or a press to get things back together, and you should probably replace the bearings at this point. brackets make it a quick and easy bolt on affair. And most brake calipers have a bracket of some sort attaching them to the upright, kartboy makes good stuff, hundreds of people are using these, and the rear brakes only see a small portion of the total braking force. failure is not something I'd worry about.

[chuckthefuk]

Got it.

I'll update the brake sticky with some thorough info.. I like the backing plate route since as you said you may as well replace the bearings.. Thanks Jamal / Waren .

-

[waren]

Thanks for the solid info Jamal. Looks like there is no reason to upgrade to 2006 knuckles (uprights). I am happy with my alignment specs for now, but rear bolts may be in my future. I should post a picture of my retro snapon camber/caster gauge mod you guys would laugh.

I will have to look into the "oem" service tool. Both manuals I have suggest removal of the knuckle/hub assembly from the car to be separated on a bench. And then pressed back together. I didnt even check the manual ... bummer. I have zero desire to mess with that rear knuckle again after just changing the springs/struts.

The above DIY post and this one http://forums.nasioc.com/forums/showthr ... ?t=1567707 (http://forums.nasioc.com/forums/showthread.php?t=1567707) are consistent with my standard bearing change out methods. Remove with 3 jaw puller (hammer as needed). Reinstall new bearing hub by tightening the axle nut down. No press.

These days wheel bearings usually come pressed into a new hub, I'll have to see if thats an aftermarket option.

[jamal]

oem service tool essentially amounts to a slide hammer and a threaded rod with the appropriate sized press tools. I've used it a few when the shop I was working for brought in a Subaru tech part-time. It's pretty sweet knowing that guy and being able to borrow the occasional tool.

you can't get one "pre-pressed in" because you have to press in the bearings, install the snap ring and outer seal, and then press in the hub.

[waren]

How did I miss the snap ring! It's all clear now.

Guess I can install those rear camber bolts!

Thanks Jamal and Chuck.

[chuckthefuk]

title updated for info continuity