Gen 6: Koni Yellow Front and Rear Shock Install (CAUTION: CUTTING REQUIRED)

Hello again everyone!

As promised, I have documented my entire process for the switch from stock shocks to Koni yellows

Special Note 1: I am running this car in HS class in SCCA Autocross, so I did not switch the springs. The process will be exactly the same if you are putting on lowering springs, I just have to keep factory springs for the class I am choosing to run.

Special Note 2: This guide is my process while installing everything in my 1.5 car garage, while using a floor jack and jack stands. Obviously, a shop vehicle lift would be much preferred, and would provide better access. I chose to do this at home rather than go to my parents' to use their lift, and had no issues!

Special Note 3: The upgraded rear swaybar endlinks in the final photo of the rear end were added after I completed this job. They use the same lower bolt to the control arm, but have upgraded hardware to the swaybar itself. Everything in this job assumes you leave the stock endlinks on, apologies in advance if that causes any confusion! In my opinion, it is worth the investment to get the upgraded endlinks if you live in an area that gets salty winters. The factory endlinks/nuts corrode so badly, and are a bear to take apart and reinstall.

Section 1: Parts installed (Hardware Included)

Front: Koni 8610-1447Sport Shocks (Caution: These are Cut-A-Struts)

Rear: Koni 8010-1055Sport Shocks

Section 2: Tools Used (in no particular order)

LOTS OF PB BLASTER

3 Ton Floor Jack

Aluminum 1.5 Ton Racing Jack

4x 3 Ton Jack Stands

Air Compressor

Pneumatic Air Gun - 1/2in Drive

Pneumatic Air Ratchet - 3/8in Drive

Plastic Clip Pry Tool

Spring Compressor(s)

Breaker Bar - 1/2in Drive

Ratchet - 3/8in Drive

Ratchet - 1/2in Drive

Torque Wrench - 3/8in Drive

Torque Wrench - 1/2in Drive

2ft 1/2in Extension

3in 3/8in Extension

14mm Wrench

17mm Wrench

19mm Wrench

T50 Bit Socket (3/8in Drive)

12mm Socket (3/8in Drive)

14mm Socket (3/8 and 1/2in Drive)

17mm Socket (1/2in Drive)

19mm Socket (1/2in Drive)

Small Plyers

Saw-z-all w/metal cutting blades

Bench Vise

Rubber Mallet

Ball Peen Hammer

Corded Drill

Drill Bits (1/8in, 1/4in, 3/8in, 1/2in)

9/16in Drill Bit (for front struts)

31/64 Drill Bit (for rear top hats)

Section 3: Specifications

As a side note, the front struts have cammed bolts to adjust camber. I set mine to halfway between the 1st and 2nd notches (if you consider the notches at 9 o'clock and 3 o'clock to be "0")

Also, since I had a loose wheel situation on our Wrangler I have made it a habit to torque the lugs on the Legacy to 80 lb/ft!

Further, some instruction sheets provided by Koni:

Section 4: Installation Walkthrough

Alright, enough delay! I will now begin the complete walkthrough for the removal of the stock components and the installation of the Koni shocks.

My first step was getting the car jacked up and set on all 4 jack stands. I did this to take all load off of the car, and also to free up a bunch of space to move around/under the vehicle. I also pulled off all 4 tires and did a rotation, but that's up to you! It was also 19F here, so I fired up my propane heater and kept proper ventilation lol

USE PB BLASTER ON EVERY UNDERCARRIAGE BOLT YOU WILL BE ATTEMPTING TO UNDO!!!

Next, I chose to do the rears first. There is no correct order, but I figured they would be easier and would allow for gradual introduction to the process. To perform this, you will need to remove the lower control arms as well as disconnect the strut tops from the body by way of the trunk. So, let's make some room in the trunk! I removed my all weather mat, any jumper cables and other crap I had back there, cargo net, and my autocross magnetic numbers.

At the least, you will need to remove the center carpet section (which has foam inserts that hold it behind the rear seats) to be able to mess with the carpet covering the fenders and top hat nuts. It just takes a bit of finessing and it will pop out. For my job, I decided to remove the center carpet section, rear cargo lip, and all plastic clips holding the fender carpet sections in place so as to allow for full access. Much recommended, so you aren't wrestling the carpet while trying to get nuts in place/torqued! The rear lip is held on by 2 cargo tie downs that screw on and off (located at far left and right on inside of trunk lip) and a plastic clip in the center. I used my plastic pry tool to pop out this and all carpet plastic clips. After you have removed them, give it a nice tug up and it should pop out!

Next, to be able to manipulate the carpet over the fenders, you will need to remove 4 things per side: 1 hook immediately inside the trunk by the weather strip needs to be rotated to pop out. DO NOT PRY, it goes in a certain way and then rotates to lock in. When the hook is in the down position, rotate 90° towards the trunk opening and remove...

...and then 3 plastic clips in the carpet that hold it to the fender.

Finally, I took all the carpet, folded it toward the center of the trunk, and then crammed it towards the back seats so it would be out of the way. Now you have a wide open area to work in!

Time to get under the car, and remove the lower control arms.

Quick note, for ease of access on the driver's side I removed the muffler flange bolts and nuts (14mm) and put the mid pipe on top of the muffler pipe . This gave a couple inches extra to access the nut connecting the control arm to the frame, but is not required.

I removed the bolts/nuts in this order: Swaybar (14mm), shock absorber (17mm), loosened the frame side nut (17mm), knuckle (17mm). By doing this, the shock will extend into the control arm while it is still connected into the knuckle/frame and then the control arm will swing free when removing the knuckle bolt. Finally, remove the frame side bolt/nut (17mm) and your control arm will be free!

Now that the strut is loose, I placed my race jack underneath it to support it against the frame. In this, you can go up to the trunk and remove the strut tophat nuts (14mm) without it falling down!

Once the nuts are removed, the strut is free from the car. Go back to your wheel well, make sure you have a firm hold of the strut and lower the jack. Remove the strut from the car!

Next you will need to disassemble the strut. You will need to compress the spring using a spring compressor and then remove the nut holding the top hat to the shock (14mm). This nut is a bear to get off. I tried to use an allen wrench in the top of the shaft to hold it still but it stripped out the hole. I ended up using a pair of vise grips to hold the shaft in place (pulled back the dust cover a little bit for access) and then a socket wrench on the nut. Bingo.

Note: The spring compressor pictured is not recommended, as it is WAY too bulky and ended up not working for the front springs. As you will see later, I went to O'Reilly and bought a more common setup of 2 independent compressors to be used in tandem!

Ok, so before you install the 8010-1055Sports you will need to widen the hole approx. 1mm in the top hat for the new shock shaft to fit. I did this with my corded drill and the 31/64 drill bit, while holding the top hat in my vice.

Make sure to clean up the hole really nice, and then reassemble the struts! In the above specifications section are the photos of the Koni instructions for assembly of the struts. Don't pull the boo boo I did and install them with the lower spring seats and springs upside down, unless you want a 2in lift in the rear and a bunch of clunking lol

I did things in this order (sorry for no pics during the reinstall as it was just the reverse of tear down)while keeping things vertical:

Install plastic C ring at base of shock shaft

Placed shiny new spring seats on shock body (dome side up)

Put on spring lined up with spring seat

Install bump stop on shock shaft

Install dust jacket

Compressed spring

Install top hat over shock shaft and top of spring

Tighten down the new lock washer and 19mm nut onto shock shaft hand tight

Decompress spring, making sure top hat rubber seat is lined up on spring and spring bottom is lined up with lower spring seat angled stop

Raise strut hat studs into trunk holes, and supported hanging strut with race jack.

Tighten and torque the 2 top hat 14mm nuts to body

Lower and remove race jack

Install control arm into body side mount, hand tight 17mm bolt/nut

Install hand tight 17mm shock bolt/nut

Install hand tight 14mm swaybar bolt/nut

Use race jack to jack control arm holes into position for knuckle

Install hand tight 17mm knuckle bolt/nut

Remove race jack

Tighten and torque the 19mm shock top nut

Install wheel and tire, torque lug nuts

Place race jack under tire and jack until the car is just lifted off of jack stand

Torque all 4 bolts/nuts on control arm

Reconnect the muffler to midpipe

Lower jack so car is back on jack stand

You have now completed the driver's side of the rear struts! Now duplicate the process for the passenger's side!

Congratulations, once the passenger's side is complete you will have finished the rear end! Goodbye factory shocks...

...hello new Koni's!

For ease of access to the adjustment nubs on top of the strut shafts, I used a utility knife and cut a slit into the carpet (just above the strut) in the trunk so I can stick the adjustment knob straight down.

I still left the car suspended in the air, as I moved to the fronts!

Pop open that hood, gonna get busy up in here.

To remove the front strut you will need to remove/do the following:

Use race jack to support lower control arm

Small plastic clip holding ABS wire to strut, use small plyers to depress tabs

12mm bolt holding brake line to strut

17mm front swaybar nut

19mm bolt and nut to knuckle (upper - cammed)

19mm bolt and nut to knuckle (lower)

12mm x3 nuts holding strut top hat to body

Lower jack and remove front strut assembly

I will warn you, you will be seeing a lot of this view if you have salty winters. My front swaybar end links were sooooo corroded on that I needed to use vise grips to hold the shaft and a breaker bar to turn the nut. I was only able to work with the lower nut, so the end links remained on my strut housings even after I removed them from the car. I made sure to have everything super tight when I reinstalled the end links, but I highly recommend just cutting them off and factoring the cost of new ones into this job. It was that much of a time killer, tbh.

Now we will disassemble the front struts. Use the spring compressors to compress the spring.

The top hats here are a pain but I worked out a solution, as I do not have the specialty sockets to do this normally:

Take a 17mm socket and place it on the strut hat nut

Insert a 7/16in allen wrench through the back of the socket to the top of the strut shaft. There is a 7/16in allen end on it

Secure a pair of vice grips to the 17mm socket

Use the allen wrench to hold the shaft in place, and loosen the 17mm nut. I used a crescent wrench to keep hold of the allen wrench

You can now remove the top hat, washer/spring seat, dust sleeve, bump stop, shock and housing, and decompress the spring. Once you remove all of that, take your shock housing over to the bench vise and prepare for the most important part: performing Cut-A-Strut surgery!

**I apologize in advance, I took some pictures here but didn't take shots of everything. I was too enveloped in the job and didn't think to take pics of cutting open the shock.**

Here are the official Koni Cut-A-Strut instructions FYI: http://www.koni-na.com/CorporateSite/media/itt/NA/pdf/boltstrut.pdf

With the shock housing in the vise, locate the exact center of the bottom and use a punch to mark it. Using a 1/8in drill bit, drill into the shock. This will pop, and gas/some oil will poof out. Wear safety goggles, it stings, trust me lol Then, either into a bucket or a pile of oil dry, drain the fluid from the shock. I did this by turning it right side up and working the shaft of the shock as a pump to work the fluid out the bottom. It's quite a bit of fluid btw.

This next part is up to you on what you use to cut the housing of the shock. I used an angle grinder to cut open the housing just under the silver collar. This allowed me to pull the guts out of the shock, and clean out the tube.

Next, I progressively drilled out the hole in the bottom to make room for the Koni hardware. 1/4in, 3/8in, 1/2in, and then finally the 9/16in bit.

I then used my saw-z-all for the precision work of cutting the tube down to the appropriate length. To be specific, 11-7/8in from the bottom of the inside of the tube to the top of your cut. To be completely honest, mine was done with a LOT of eyeballing. I stuck a tape measure and a ruler down in to see where I needed to aim for, and made probably 4 cuts to get myself closer and closer to that mark. I then used a rotary tool and file to clean up the cut edge.

Next step is securing the 8610-1447Sports into the shock housing. Tap the supplied collar into the cut hole with a rubber mallet, and place the rubber sleeve over the opening. Now, place the Koni into the hole and the nubs on the Koni housing will stop it from going any further in. We will need to walk this into the OEM housing. I did it as so:

Insert just the supplied black bolt into the bottom of the shock housing, and begin to tighten it into the Koni.

Using a T50 Socket (I had torx in 3/8in drive), tighten the bolt until you see the nubs begin to walk into the collar. Stop!

Back the bolt out, and now use the supplied cupped washer/lock washer/bolt together.

Tighten, and torque to 55lb/ft.

Now you're ready to put it all back together, and it should go as follows:

Install plastic C clip on base of shock shaft

Install bump stop on shock shaft

Install dust sleeve

Install spring, lined up with angled stop on lower seat

Compress spring

Install upper spring seat/washer

Install strut top hat

Tighten down the new lock washer and 19mm nut onto shock shaft hand tight

Decompress spring, making sure rubber seat is lined up on spring and spring bottom is lined up with lower spring seat angled stop

I used one arm to raise the strut assembly into the wheel well and the top hat studs into the body mount holes.

I used the other arm to put the 12mm nuts on finger tight to the studs

Install 17mm swaybar end link nut and tighten

Use race jack on lower control arm to meet knuckle to holes on the strut housing for the 19mm bolts

Install and moderately tighten both 19mm bolts/nuts to knuckle

Torque 12mm nuts on top hat to body

Torque 19mm shock top nut

Lower race jack

Set camber on top 19mm knuckle bolt

Torque both 19mm knuckle bolts/nuts

Install brake line/12mm brake line bolt

Install ABS clip

Congrats, you have now installed the Koni Cut-A-Strut assembly on one of the front corners! As you can see, from the outside nothing really looks all too different. The only noticeable thing is the adjustment nub now poking out into the engine bay.

Repeat the process for the other side, and by golly you will now have Koni adjustable damper shocks on all 4 corners of your beautiful 6th Gen Legacy!!!

As I did not do springs, there was really no noticeable ride height change.

However, the ride is now VASTLY stiffer and the steering is very responsive. Even without the dampers turned up, the car handles so much tighter and has become very predictable when cornering aggressively.

I will report back with updates when necessary, but the real test will be the 2021 autocross season. This will give me the most info on the nature of this mod, and I will be sharing any and all discoveries I have.

Thank you, and please feel free to ask any questions whatsoever. Hopefully this guide helps someone out there who isn't as accustomed to tearing things apart and rebuilding them as I am!

What part of PA? I've got these in my trunk but I've been putting off putting them in.

Northwest PA, Erie specifically!

did this for my outback also. was a fun job.

https://www.subaruoutback.org/threads/outback-2-5xt-on-legacygt-koni-shocks-and-rallitek-springs.524189/

did this for my outback also. was a fun job.

https://www.subaruoutback.org/threads/outback-2-5xt-on-legacygt-koni-shocks-and-rallitek-springs.524189/

 

That's awesome!!

Hey! Figured I'd give a quick update now that we have completed our second local event.

The car handles SUPERBLY, even for being an underpowered gramma's car lol

The first event I ran the dampers at 1.5 turns, and the rear sway bar at the softest setting. The car handled really well, but I didn't get as much rotation out of it as I could. I was, however, able to figure out the stability control removal and with those aids gone the car actually breaks some tire loose and rotates hard through corners! Here's a video compilation of that first event:

I ran the Koni's at full stiff this last event, and the rear sway bar at medium stiff and the car was manageably tail happy. I'll move the bar to full stiff next event, and then compensate for the squirliness with lower rear tire pressures. Overall the tires weren't getting too hot, and the main issue was that I was over driving it into one of the tight corners.

I have been 0.5sec slower than a fully equipped Fiesta ST in both of the first two events, so I know I can make up that time being a little smoother!

10/10 would recommend this and the 24mm sway bar for motorsports in these cars!