subframe swap

[nztintin]

ok i'm looking at putting a wrx front subframe into my forester to try get the suspension alighnment a bit better (foz subframe has 25mm spacers on it), i've searched around as many sites as i can (here, ozfoz, gtrydaz etc) but can't find a definitive answer on whether i'm going to need to shorten the foz steering knuckle or replace with a wrx one....

so anyone know what issues i will run into by having the subframe 25mm higher?

[Optical]

I havent seen the forrester steering knuckle, but if the arm bit is higher then you will get horrible bump-steer if you dont change to wrx hubs...

otherwise a whiteline roll centre adjustment kit might get you close

[Guest boostcut]

 Optical said:

I havent seen the forrester steering knuckle, but if the arm bit is higher then you will get horrible bump-steer if you dont change to wrx hubs...

otherwise a whiteline roll centre adjustment kit might get you close

are we talking about the steering shaft "knuckle" as in the universal joint from your steering wheel to rack?

or inner rackends and balljoints?

[Optical]

oh whoops, i was thinking of the arm on the hub the steering rack connects to.

there are a couple of different steering rack universal joints, you'll need to change it if the subframe goes up more than about 5mm. One of the impreza or leggy UJ's is bound to be a straight swap. If you can take a pic of the steering column end i should be able to tell you

[nztintin]

ok i've found this, i'm dumping it here so i don't loose it

 

steering joint/knuckle

- either way, you should release at least the upper bolt.

- if you want to re-use the joint/knuckle, then remove the bolt at the upper end so it slips upwards to prevent any tension when the chassis/steering column lowers closer to the steering rack/sub-frame.

- replace that original bolt with a thinner bolt that will allow it to slip all the way through, so, you can add a locking washer & nut. this step is just to be safe.

sub-frame spacers

- remove the front wheels.

- raise the front of the vehicle, and support the sub-frame using jack stands. (i used the scissor jack for raising/lowering the chassis.)

- starting with one side (L or R), remove the nuts (2 per side) from the sub-frame bolts.

- if you have the shorter impreza sub-frame bolts, you will remove the longer forester bolts that are clipped onto the chassis frame with a circular piece of plastic. the spacers are attached to the chassis frame, too. just wedge them out with a flat-head screwdriver.

- if you want to re-use your longer forester bolts because you're in a major rush and can't get the shorter impreza bolts because there are no nearby subaru dealerships, then you can. just re-use the spacers by placing them underneath the subframe.

- replace all 4 nuts (2 either side).

- don't forget the wheels.

tranny cradle spacers

- remove the 2 bolts from the lateral piece of the tranny cradle.

- remove the 2 nuts from the center of that same tranny cradle piece

- the spacers on either end are spot-welded (2 for each spacer). i used a hacksaw on one spacer and a dremel on the other.

Image

- break the spacers free by hitting them. i used a hex key, and hit that to help break the spacers off. (see picture above)

- make sure to grind or file the weld and smooth that section out. you can even repaint it with rust paint.

- replace the tranmny cradle placing the 2 nuts, from the center, back.

- you will need the shorter impreza tranny cradle bolts to re-use your forester tranny cradle.

voila! it wasn't really hard at all. the longest time will be spent with the front sub-frame spacers when you are trying to re-align the sub-frame back onto the chassis to bolt up. i was doing this all by myself with just a scissor jack and one tiny hydraulic jack.

you probably won't have to adjust camber, but i think you may need to get a wheel alignment, since my toe was really bad and the steering wheel was cocked to one side.

the arms on the foz are out of alighnment due to the foz sitting lower than standard (and soon to be lower) so raising the subframe height will put the alignment back towards stock (assuming stock was good???)

 boostcut']

[quote name='Optical said:

I havent seen the forrester steering knuckle, but if the arm bit is higher then you will get horrible bump-steer if you dont change to wrx hubs...

otherwise a whiteline roll centre adjustment kit might get you close

/quote]

are we talking about the steering shaft "knuckle" as in the universal joint from your steering wheel to rack?

or inner rackends and balljoints?

I'm talking about universal from rack to steeringwheel.... i hope thats what the others are meaning too.....

[Guest boostcut]

ok mint... ahhh you could modify or get a wrx one... theyre easy to change just mark it etc before removal

[nztintin]

ok time for an update

car is now sitting on axle stands with engine propped up on a jack as i have removed all the subframe and steering etc

now i'm getting to an awkward place where i need to get the steering knuckle issue sorted, i now know what the issue will be (I'd never really had a look at the steering etc on my car)

The steering knuckle will definatly need to be shorter or i will have to modify the knuckle\steering splines to get the forester one to fit.

so does anyone have a gc8 steering knuckle they could measure for me so i can figure out if it will work???

here are some pics of whats been done so far

New rack as i got it

foz steering knuckle

Old rack and new rack (new rack with no boots or ties rods)

code sticker on the new rack (supposidly from a 555 wrx ra, 2.5 turns lock to lock not 1.5 as the seller described it to me :'()

[Optical]

2.5 sounds right, 2.2 is the quickest ratio ive seen subaru produce

yep ive got a universal i can measure, will do later tonight

[nztintin]

ok so new developments (also posted in my looking for ubolts thread) found some parts i need\want to be fricking expensive and are gonna take excessive amounts of time to get.

 

prices has requested.

subframe bolts are $67.00 plus gst each . ex japan x 7 days.

tie rod end $105.00 plus gst each.

steering rack boot $51.00 plus gst each.

 

The prices for the requested items are as follows -

KSR202 - $72.50 + gst. HD steering rack mounts

KCA313 - $418.50 + gst. (bump steer kit)

Unfortunately we do not keep these items regularly in stock due to low demand. We can order them from Whiteline to come with our regular orders with a delivery time of approx 6 weeks, or airfreighted in approx 3 days with added freight costs of approx $80.00.

so new questions,

*whats the difference between the whiteline hd steering rack kit and the nolethane steering rack mount kit? any advantages in the whiteline kit??? I'm pretty sure i can get the nolethane ones from repco fairly easily.

*will get steering rack boots from repco, $16 each for subaru specific ones.

*Subframe u bolts

 boostcut said:

go get some stainless capscrews from an engineering wholesaler... i got them in mine and they look sick... i only replaced them because i was missing a nut off my old ones

good idea???

*bump steer kit can wait, was only looking for intrest sake

*Tie rod ends, any advantage in replacing these? the ones off my car still look sweet obviously a bit worn being 11 years old.

oh and still waiting on that steering knuckle measurement optical

[Tony]

 nztintin said:

*Tie rod ends, any advantage in replacing these? the ones off my car still look sweet obviously a bit worn being 11 years old.

Its not a bad idea to replace them - you may as well since you are putting the new rack in. But Subarus price is craaaaazy. I went to get some the other week and nearly fell over when they gave me that price! I ended up getting some from our local Autolign, and they were nowhere near as expensive (around a third of the OEM price).

[nztintin]

ok so finally went shopping yesterday, repco was alot cheaper than subaru genuine(no surprises)

so i now have new rack boots and nolethane rack bushes all mounted up, tie rod ends are being ordered in for me through repco and i have bought some 2nd hand u-bolts and a wrx steering universal off a guy on trade me so once i get those parts i will hopefully be able to get the car back together and back on the road!

[cpt kernow]

I got confused when you mentioned knuckle, but you mean the Universal joint?

The rest of the rack won't make a difference as it's all attached to the subframe, so will stay in the same relative position no matter what you do to the body spacers.

Good work on changing the rack though. I've thought of doing that to quicken up the steering.

[nztintin]

yeah i just wanted to remove the spacers cause the car is going to be lower soon and i want to try keep the lower arms at a half decent angle and bump steer adjusters are over $400! will be interesting to see how the spacer removal helps cornering.

I'm just really hoping the wrx knuckle\universal will bolt straight in so i don't have to modify anything, i don't like "modifying" steering related things :-\

[nztintin]

could do, but they weigh 1kg+ each so i wanna get rid of them

[Guest boostin]

You'll need new lower arm bushes too. Foz and Outback have the stepped bushes to keep the lower arm pivots in line.

I think the front of the gearbox mount has spacers, as does the rear suspension.

[nztintin]

 boostin said:

You'll need new lower arm bushes too. Foz and Outback have the stepped bushes to keep the lower arm pivots in line.

I think the front of the gearbox mount has spacers, as does the rear suspension.

ah well that aint gonna happen, wrx rear bushes don't fit the forester chassis, and i remember some semi-trustworthy person telling me forester rear bushes are similar to an antilift kit when put on a wrx???

yup tranny spacers will also be coming out on this mission, will look at the rear once i can put the front of the car back on the ground.

[nztintin]

the "step" on a forester chassis is different to wrx so physically won't fit. I tried when i put the alloy lower arms on, foz bushes would fit a foz but not vice versa.