Subaru Outback Forums banner

DIY: Gen 4 Rear Sway Bar (RSB) Upgrade - OEM 19mm

69K views 62 replies 40 participants last post by  NikolaTesla 
#1 ·
This modification is for upgrading the stock rear sway bar (RSB) to the OEM Subaru 19mm RSB. The general purpose of this upgrade is to reduce understeer and increase roll resistance. Handling characteristics are noticeably improved at highway speeds, however you may experience a slightly "stiffer" ride in city driving (but cornering all around feels better).

Equipment needed: OEM Subaru 19mm Sway Bar (P/N 20451FG020 you can get here), two larger stabilizer bushings (P/N 20464FG020 x 2 you can get here)
Tools needed: Socket wrench and sockets, torque wrench (optional), pliers (optional), ramps (optional)
Level of difficulty: Low
Time needed: 30 minutes



It is not necessary to drive the rear wheels onto ramps or use a jack/jack stands, however if you have them available it will give you more space to work in.

First, you need to locate the stock RSB under the rear of the vehicle and remove the four 12mm bushing bolts (orange circles below). Next, remove the two 14mm end link nuts (blue circle below). NOTE: the 14mm bolts have a tendency to be rusted (mine were) so I used pliers on one side and on the other side removed the nut with a socket wrench.



Remove the stock RSB and stock bushings, then install the 19mm RSB and new, larger bushings. Bolt everything back up (the torque specs are as follows: 12mm bolts - 28.0 ft-lbs; 14mm bolts - 24.3 ft-lbs). One thing to take note of us to make sure the hump in the middle of the RSB is facing upward, i.e. away from the exhaust pipe as in the picture below:



And you're done! Enjoy better handling.


Reference: https://www.subaruoutback.org/forums/104-gen-4-2010-present/24867-sway-bar-mod-picture-tutorial.html
The picture links were dead and didn't fully explain some potential problems areas so I thought I'd write a new one.
 
See less See more
3
#8 ·
I just wanted to +1 both the instructions and the benefit of upgrading to the 19mm sway bar. I installed one a couple of months ago on our '14 and it's been an improvement in all circumstances -- the car turns into 35mph curves more precisely, passengers notice less lean, and tracking on the highway is better -- with no loss in comfort or any other down side that I've been able to notice.
 
#11 ·
This looks like a fun thing to try on my 2015. The car handles fine but I'm curious to see if there is a noticeable difference in having a stickier hunkered down feel or if the ride will become noticeably more harsh. I can always switch back to the OEM bar if it's not my kind of ride.

I'm assuming that this won't void any warranties since it's a Subaru part, and also that the end links won't suffer abuse from the stiffer bar…?

One question - did you lube the bushings and if so using what lubricant (or was lubricant included with the kit)?
 
#12 ·
Hi All
Thanks to AO River for the great write up :29:. I did mine last weekend (2014 H6) with some other stuff. I also replaced the end links and went with poly bushings. I did notice an improvement in the rear end float feels much better even wife noticed it. For the end links I used Rallitek end links - they look like stock except beefier. They were also about 3/16 shorter than stock but bolted right up with no issues. Except the Rallitek comes with a captive nut VS the std nut on stock - I wish I had a 14mm rachet box wrench - it would have been a lot easier... The poly bushings went on fine but the retaining bracket is a universal bracket with slot for the bolts while the stock bracket has holes. I found the universal bracket could not tighten enough to stop it from moving so I am going to try to reinstall the stock retainer with the poly bushings. The write up is from a 4H with single exhaust. I have the H6 with dual exhaust. I was concerned about getting the bar out/in with the 2nd exhaust in the way but it turned out to be real easy so if you have H6 with duals do not hesitate to do this great upgrade.
 
#13 ·
OK, so it has been mentioned several times in various threads that the thicker sway bar decreases rear wheel travel.

Why and by how much?

Also, does the bar really improve cornering stability or does it simply create an illusion? The former would be nice, the latter...not so much.

Thanks!
 
#20 ·
Per 2014 OB manual: Stabilizer Link to Rear Lateral Link Torque

33 N-m
3.36 kgf-m
24.3 ft-lb

I just swapped my bar to 19mm yesterday and gave my wife whiplash from too many lane changes.

This is by far the best price/performance upgrade out there.
 
#19 ·
I just donwloaded a free service manual for the torque spec. It's 24.3, same as the nuts on top.
I finally got this thing on, definitely wasn't a 30 minute job for me. For anyone doing this upgrade to a car that's a few years old and has some rust, I highly recommend getting new endlinks. Also, please note that the end link needs to go in the lateral link before they attach to the swaybar. I attached the endlinks to the sway bar, then put the whole thing in as one unit (don't do that). I ended up needing to disconnect them from the sway bar in order to get them into the arm, then reconnect them on top last.
 
#40 ·
Has anyone tried the reinforcing bracket that 03LLBean mentioned? I don't really want to spend the extra money if not needed for my 2015 Outback, but if Subaru designed the end links and mounting brackets (not u bolts) for a certain spec, I have some hesitation that these parts would be designed to handle double the spring rate of a 16 mm going up to a 19mm (found a sway bar spring rate calculator..surprising amount of change in strength of the spring (SB) with a little bit of diameter increase)



I have seen several people talking about Moog end links stating that they are more beefy than factory, but are they really? If possible, can anyone give some level of quantification on this (I know, difficult to say...just trying to get better informed)? I took a look at the pictures on the Moog site and they looked about the same as the factory links, but hard to say if picture is accurate.

Any other suggestions on end links?

Thanks much!
 
#27 ·
why is my Subaru dealer telling me this RSB is designed for an Impreza and will not fit the Outback?
They are correct about the first half, and half wrong about the second half. It will not fit unless you also get the upgraded bushings. Once you upgrade both the bar and the bushings it fits perfectly.

Technically this upgrade is not "meant" for the Outback, it just happens to fit. But SOA did not make this sway bar for the Outback per se. That being said it's a great upgrade and SOA arguably SHOULD have labeled this as an applicable upgrade for the Outback :) I'm sure that requires quite a bit of diligence though.
 
#29 ·
I bought this mod and installed it about a month or 2 ago now. I must say...WOW...don't question this one bit. Just buy it and get it done. It's the best 100 dollars you'll spend. and if you go to subaruonlineparts.com to purchase it and spend over 100 bucks it's 5 dollar shipping. I bought new windshield wiper rubber and the sway bar and bushings and it was the same price as just the sway bar and bushings after tax :)
 
Top