WRX Wagon Aluminum control arm install

[Big Sky WRX]

Get a lot of requests for this (upgrtaded them on my sedan) and recently installed a set on my new wagon, so here goes.

one note on sway bars and links- if you go to aluminum arms on a wagon, you're going to need a sedan front bar and sedan style front sway links- this is true for sedan arms or the old GC8 arms

First schematic of front suspension (note insert of aluminum control arm):

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The ever important torque specs

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You need to get your vehicle up on jack stands and remove the front wheels. Next remove the plastic guard and subframe- no pics of this, but pretty self explanatory- the subframe has two 12mm bolt heads up front followed by 6 (3 to a side) 17mm bolt heads and then four 14mm bolt heads (two to a side).

Remove the sway link bolt at the top (you can leave the lower attached to the arm if your using a different link or remove completely if reusing the stock links)

It's 14mm

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Next remove the bolt that hold the ball joint into the knuckle it's 14mm also

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Suspension tech tip- use 6 point sockets and wrenches, many of the components are heavily torqued and it's east to "round" a bolt head or nut- 6 point will help avoid this. Also for the 17mm and up bolts/nuts you'll want 1/2" drive stuff and if you have air available it will help too.

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Remove the nut on the front control arm bushing (housed in the cross member). This pic shows the bolt head (the nuit is to the rear of the vehicle). Just remove the nut for now- leave the bolt.

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Next remove the two bolts that hold the rear bushing to the chassis, they're 19mm and are on good (maybe bad depending on how you look at it- torque is 184 ft lbs!)


Front bolt

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Another angle of the rear bushing

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Extract the ball joint form the knuckle, you can use a hammer to tap on top of the arm to help knock it out

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Finally remove the bolt holding the front bushing to the cross member and gently remove the arm.

If successful you should have one old arm out and a new to go in

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Install the new arm like so

Bolt the rear bushing to the chassis, but not tight.

Install the bolt for the front bushing and temporarily tighten.

Insert the ball joint into the knuckle and torque to 37 ft lbs.

Connect the sway link to the arm and temporarily tighten

The suspension needs to be under load to tighten- that means remounting the wheels and runing it up ramps to finish tightening.

Tighten in this order sway link- 33 ft lbs

front bushing/crossmember 74 ft lbs

rear bushing 184 ft lbs!

Your done.

[socrates42]

did this give you any alignment issues on your wagon, as the sedan has a wider front trac?

[Big Sky WRX]

Originally posted by socrates42
did this give you any alignment issues on your wagon, as the sedan has a wider front trac?

No problems as I used GC8 (old style WRX) arms. GD arms on a GG would be more than just alignment issues- the axle shafts are shorter on the GG as well- could cause some expensive problems.

Big Sky

[Midwestrider]

Ok dumb question here.. what is benfit to doing this.. stronger part?

Also what year GC8 did you source these from and the cost of them?

Eric

[Dan_jast]

Originally posted by Midwestrider
Ok dumb question here.. what is benfit to doing this.. stronger part?

Also what year GC8 did you source these from and the cost of them?

Eric

basically, its stronger, so you will be able to corner harder/better. Theres probably some more pros to it to but i dont know.

And i got a question, Do the USDM STI have this part on stock, i would think they do but i never got to look under a usdm sti.