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19mm sway bar

818K views 2K replies 378 participants last post by  Bassman 
#1 ·
I just completed the 19mm sway bar modification. I know this mod has been mentioned in another thread, however I think it would be useful to have its own thread to consolidate all the info out there for those who are considering doing it.

I’ll aim this post at someone like myself who rarely works on cars but has a basic tool knowledge that goes a little beyond righty-tighty, lefty-loosey, but is also a little intimidated by the thought of “ripping apart” a brand new car whose suspension is really very adequate as is. I’m completely A.R . about knowing exactly what is the correct way to do something and using the proper tools to do it. I spent hours researching all the threads I could find on Subaru forums, as well as researching other issues and questions that arose as a result of that effort. The most helpful info I found was on this forum:

http://www.subaruoutback.org/forums/104-gen-4-2010-2014/24867-sway-bar-mod-picture-tutorial-7.html

First of all, why do it? I’m actually still not sure exactly why. It’s my understanding that the stiffer 19mm bar will essentially enable the back of the car to follow the front of the car in a more responsive way than the OEM 16mm sway bar and should reduce the rolling feeling in sharper turns. I liked the feel of the original suspension but was curious what difference it might make. The bar runs the length of the rear axle and connects the left and right side suspension assemblies together. My concern was that I would trade up to crisper handling at the expense of a harsher ride. That concern turned out to be totally unfounded.

Secondly, how hard is it and what tools and experience level do I need? Big picture, it’s ridiculously simple. You’re essentially undoing 6 bolts, swapping out the OEM bar for the 19mm bar, and re-tightening the bolts {on a new car with no rust you could probably get away with any kind of a 12mm and 14mm wrench (or rachet) as a bare minimum, but more on tools later}. The bar is a long rod running underneath the back with a 90 degree forward bend in each end. The ends are attached by a 14mm bolt to the upper end of a short vertical piece about 4” long called an endlink. The lower end of the endlink is attached to the lower control arm on the rear suspension. The bar itself is bolted onto the car frame at each end by a C-shaped clamp with 2 12mm bolts at the top and bottom of the clamp. The clamp holds a 1” wide bushing which encases the bar. It took me about 2 hours because I took my time and looked around underneath and thought it through so that I wouldn’t find myself undoing something I couldn’t put back together. If I did it again I could easily do it in under 1/2 hour. The most time-consuming thing would be using Goo Gone to remove the part sticker that peels off in microscopic pieces.

So how do you do it? Here is where it gets a little not-so-simple because I read a lot of conflicting advice, but here is the sum total of what I could glean.

1. First position the car properly. Everything I read suggested that this install should be done with the suspension loaded (ie. weight on the wheels). Right away I got confused because the Subaru recommended procedure for the install has removing the wheels as the first step. I modified their procedure and left the wheels on as most people seem to do. Also, you could probably scoot underneath in a pinch, but it becomes a whole lot easier to raise the back end on ramps or jack it up and lower it onto wheel cradles. I used Race Ramps RR-30 Rally Ramps and they were perfect:

http://www.amazon.com/gp/product/B00H5PTQIU/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1

I hate trusting my life to a single point of failure so in addition to using ramps with the parking brake set, I also positioned backup jack stands and chocked the wheels.

2. To remove the bar, I first disconnected the 14mm endlink attachment. This bolt has a smooth flat end on the outside end facing the tire, and the other inside end has a hex cutout in the bolt end that accepts a 5mm allen wrench. On a new car you could probably get it loosened with a 14mm rachet or wrench and spin it free by hand. If the bolts are rusted or stubborn, once the bolt is initially loosened it may spin with the wrench, so it would need to be held on the same end as your 14mm wrench by a 5mm allen wrench inserted in the bolt end. The ideal setup is a ratcheting 14mm boxend wrench on the nut with a 5mm allen wrench on the same bolt end, but you could probably figure out a way to coax it out using less orthodox methods.

Next you simply loosen and remove the 4 12mm bolts holding on the 2 bushing clamps. Don’t worry about it falling - even with the endlink bolt nuts removed the bar is still held in place until you maneuver it off the bolts. Make a note when you remove the bushing clamps that they are also secured at the top by a hook that goes through a small hole in the bushing mounting plate.

3. To install the new bar, most people have been using this Subaru part:

Subaru Outback Rear 19MM Sway Bar Kit (Part No: 20451FG020-20464FG020 x2)

You have to first position the two bushings on the bar - there is a split in the rubber that opens to fit it over the bar. The kit comes with instructions on where to position them but big picture there’s really only one place that they can go and it’s pretty obvious if you look at the original bar. The bushings that come with the 19mm kit are stamped “18”, and the bushings on the 16mm OEM bar are stamped “15”. It all works, so go figure...

I first loosely installed the 14mm endlink bolts, and then lightly bolted on the 12mm bushing clamps to make sure the bushings were centered properly. Then I snugged down the endlink bolts a little on each side at a time until they were pretty tight. Then I used a torque wrench and tightened to spec (14mm bolt is 24.3 ft-lb). This is where having the rear end raised on ramps is really nice to accommodate the extra shaft length of a torque wrench. Then I torqued the 12mm clamp bolts to spec (28.0 ft-lb). That’s all there is to it!

So here are some questions and “tips” that I came across to muddy the waters.

1. Will this void the warranty? PROBABLY NOT given that it is a Subaru part. It would have to be shown that the install caused some problem. Consensus has it that a Subaru mechanic wouldn’t even notice the difference with a casual glance. If you use an aftermarket brand then I don’t know.

2. Will the stiffer bar require a “beefier” endlink? Apparently not.

3. Should you lube the bushings? The original bushings show no indication of a lubricant. They are made of softer rubber and work fine by themselves. Aftermarket poly bushings are made of a harder material that will eventually squeak if not lubricated.

4. Should you use locktight or some kind of lubricant on the bolts? The original bolts show no evidence of this.

I learned a lot about torque. Torque specs are based on “dry” hardware. If there is anything that eases the way the parts move during tightening (eg locktite, anti-seize, etc) you can actually overtorque a bolt to the point of snapping it off. Don’t overthink it - I wiped my bolts dry and torqued them down just fine. You could probably get away with the backyard mechanic special of tight plus one more push for good measure. I also learned that a torque wrench should be calibrated and stored with the torque at the lowest setting. I pitched my 20-year-old wrench that had sat forever with the torque at a high setting and got a new one.

When all was said and done, I honestly can’t discern a noticeable difference in handling, but I sure had fun doing it. It did track straight as an arrow through a wicked crosswind the other day. If anyone can correct anything I said please chime in because I’m by no means an expert.
 
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#89 ·
Is part # 20451FG020-20464FG020 x2 a Subaru part number or is that just the one used by the seller?

I live in Canada so it may end up being cheaper for me to get the sway bar from the dealer than importing from the U.S. I can't find anyone online in Canada who stocks it (or maybe I don't know where to look).

I haven't checked the dealer price in Canada yet.
 
#91 ·
Any drawback if the bar is put on where it points down instead of up. If fits both ways. You use rotate it 360 to change it. Mine was installed with the bar dipping down and besides hanging a little lower(i do not off road) it rides and drives great.
 
#92 ·
None and I will install mine the other way when it comes! I ordered it weeks ago (20mm natl. back order still) I'm told about two more weeks and it will be sent.


It is the twist between the two sides that it comes to function.
 
#93 ·
Keep in mind that Subaru makes parts like this that fit a wide variety of years and models. To some models/years that dip is maybe critical, and with some it's not. If there is ANY possibility that the bar will hit anything, flip it over to the position that the original bar was at.
 
#94 ·
Well I had a reason to hook up my trailer today and try out the 20MM Sway bar.
I can say that I had a hard time remembering the trailer was back there. I have the bike positioned so that as you see it here the trailer tongue weight is 120 Lbs. I weighed it to be sure.
Weight of the trailer with bike is about 1250 Lbs.
I had it up to 70 MPH on the freeway and it was rock solid. Not like my 2014 with stock sway bar.


 
#97 ·
Because it reduces rear wheel articulation, making driving forest service roads more harsh. The rear wheels are now less independent of each other. Subaru needed to strike a balance with this car. You guys put more value on on road performance.

I put a 20mm on my 2005 Outback XT and while it improved on road performance the off road performance suffered substantially. I ride a lot of dirt roads and the new 2015 is a dream ride on the dirt compared to my modded 2005.
 
#96 ·
Had the same problem on my 2010 Forester XT. Thought it would flip over on sharp curves before replacing/upgrading both SBs. Subaru just doesn't get it!
 
#100 ·
... any recs for which would be better? 19mm or 20mm?
"Better" is subjective, and depends a lot on how your vehicle is loaded, your driving patterns, and what kind of roads you usually travel. Consider that the torsional stiffness of the stabilizer bar goes up as the 4th power of its diameter, so the 19mm bar will be ~99% stiffer than the stock 16mm bar, and the 20mm bar is ~144% stiffer than stock. Since I am a conservative, engineering type, I think the 19mm stabilizer bar is a better first choice. You can always install a 20mm bar later if the 19mm bar turns out not to be stiff enough for you.
 
#102 ·
I'm pretty sure it's the 16mm for all models including the 3.6. I just installed my 19mm about half an hour ago, and lemme tell ya, I can't say enough good things about this mod! I noticed the difference as soon as I pulled out of the driveway. I took her through some hairpin turns and the steering is far more responsive and the front end actually feels lighter! The rear end feels more planted to the road, and it actually feels like a Subaru now! Yes, I can feel the bumps a little more, but my comfort comes from knowing she'll be more stable towing a trailer or camper, and off road, I'm not looking for a comfy ride anyway. Thanks to everyone on this board for encouraging me to make this mod!
 
#103 ·
Thanks for the reply. That is what I suspected just based on everyone swapping them out. I guess you could measure it.
If I end up changing mine out I'll do that.
Not sure if I wanna mess too much with a 35K new car though. It sounds pretty easy but I'm not very mechanical....

What part would you order? One found says 2010-2014. Do you need anything besides the part?
 
#105 ·
Read through this thread. Many answers. If you don't want to do it, a mechanic can in 20 min. Shouldn't cost much. Have it done with your next oil change. Remember this is a Subaru part, identical to the stock one but a bigger diameter. It comes with the larger bore needed bushings. End links are fine as is. The 4th gen part is the same but you can also find it listed as a 2015 part on the Sub parts site listed in this thread.
 
#104 ·
I just ordered my 20mm kit from Subaru online parts. I ordered the 20mm because I drive a long way on the road, usually mountain roads and then a little bit on the rough stuff.
Delivery won't be till late Feb. if I'm lucky. They told me to think early March. I'm eager to get it done!
I hope this site is getting a cut! I'm sure a lot of that wait is from guys around here.
Cheers!
 
#108 ·
I ordered mine Dec 14th... I suppose i'll get mine when you do :)


it's the wife's car anyway, she'll never notice. I drive in every few weeks. I'll like
 
#107 ·
Anybody have a link to the actual part for this that they actually installed? People are telling me there isn't one for the 2015 model yet?

I am trying to find out what someone would charge to install this. This is where they said there isn't on for the 2015 model listed yet.
 
#114 ·
I've driven in snow with the 19mm and could not noticed any deterioration in ride quality. Thinking about it, articulation is rarely an issue in snow. You are more likely to feel it going off road, or perhaps a pot hole.


Although I have not taken it off road, I cannot detect any drawback to doing the 19mm upgrade. Don't hesitate. There really is a noticeable difference when driving, especially curvy mountain roads, quick turns or lane changes, and highway on ramps.


good luck
 
#116 ·
Live in WA but thanks for the offer.
I might actually have the needed tools. I guess I need to go back through this thread and see if it is something I want to try.
Just a little nervous on such a new vehicle and I'm not really very mechanical on cars.
Working on my bicycles is about as mechanical as I got, and that was mainly because I was riding so much I HAD to learn how to do stuff myself, not to mention I couldn't find anybody I could really trust to do the work right.

Now in search of a good Subaru mechanic is another story....
 
#117 ·
The sway bar was the easiest thing I have done to the car so far. I did not even jack it up. Which is why I was so quick to make the offer.
 
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#121 ·
In theory... Perhaps it keeps ESC from needing to engage, because you stay flatter, more contact area = more traction = less slip and less likely to spin out ?


In theory... ABS could engage more (with 19mm) than it would have (with stock), because there is less articulation and a wheel could bounce up in rough terrain and computer could think it is spinning.


Those are pretty extreme theories though, and neither is a safety concern IMO. In practice, there should be no difference or impact to ESC or any safety feature, unless (digging deep for this)... IF you are the type of driver who OVERSTEERS in a panic situation... Manufacturers intentionally design cars to UNDERSTEER because average drivers do tend to crank the wheel too much, especially at fast speeds. Changing the sway bar theoretically reduces understeer a little, so would have less buffer for those who drastically oversteer.


long story short, no safety concern I can really imagine, and I'm a very safety focused driver and research the snot out of safety stats.


good luck
 
#120 ·
It was the first thing I did, and it was very easy (if you read up on what to do, exactly)

You don't notice it a lot, except in hard turns or movements. I don't think the stock rear sway is that bad, considering that most of us aren't going to push it hard through the corners. I do appreciate the reduction in rear movement and understeer, personally, but I don't think anybody should feel compelled to swap it out.

If I were doing some serious off-roading, I would leave the stock one in, or get one you can disconnect - I think it could get unpleasant. Normal off-roading, it's probably fine with 19mm :)
 
#135 ·
I, too, would like to know. A dealer mechanic told me of someone with the STi bar who reportedly is very happy with it, but said person drives mostly dirt roads and such to go climbing, not rockier, tougher terrain where it might limit wheel travel, no?
 
#124 ·
So I just installed the 19mm, and I'm hoping I didn't mess it up. When I put it back on, one side was really difficult to retighten the bolts. I forced it, but I'm wondering if I stripped the bolts or if that's a bad thing to have the bolts have a really tight fit. Also, it seemed as if the end links may have a slight angle now, but that's the only way I could get it to fit on there. It only took a half hour, but not being mechanically inclined, I am just hoping it's ok. Any reassurance would be greatly appreciated. :)


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#125 ·
So I just installed the 19mm, and I'm hoping I didn't mess it up. When I put it back on, one side was really difficult to retighten the bolts. I forced it, but I'm wondering if I stripped the bolts or if that's a bad thing to have the bolts have a really tight fit. Also, it seemed as if the end links may have a slight angle now, but that's the only way I could get it to fit on there. It only took a half hour, but not being mechanically inclined, I am just hoping it's ok. Any reassurance would be greatly appreciated. :)


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The above is exactly why I really don't want to mess with it myself... It sounds like something I would be posting after attempting/doing the job myself. (If I even got it finished... :surprise:
 
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