How To Eliminate Sag and Sway While Towing Boat Trailer With Subaru Outback Wagon

Updated 06/03/2019 | Published 05/31/2019

Products Featured in This Question

Coil SumoSprings Custom Helper Springs for Coil Spring Suspension - Rear Axle

(409)

$186.99

Equal-i-zer Weight Distribution System w/ 4-Point Sway Control - 4,000 lbs GTW, 400 lbs TW

(840)

$800.00

Pole-Tongue Adapter for Equal-i-zer Weight Distribution Systems - 14,000 lbs GTW, 1,400 lbs TW

(70)

$145.24

Question:

I have a 2018 Outback 3.6R towing a boat trailer ~1500 lb gross, ~200 lb tongue wt.. Most importantly, I am getting a bit more trailer sway than Im comfortable with under certain road and passing car situations. The trailer also tends to bounce up and down pretty hard on uneven roads even though the tongue weight percentage is less than 15 of the gross weight. There is a bit of sag in the back end but no bottoming out even when the car is fully loaded with luggage and people. Increasing the loaded rear ride height would be nice as it would help the trailer clear the ground on ramps and driveways. I have seen recommendations for using a beefed up rear anti-sway bar 19 mm vs. the stock 16 mm to help combat the sway from the soft suspension but that would not address the sag. The helper springs would help the sag but it is not clear to me how they would affect the sway issue. Its also not clear to me if either the helper springs or the stiffer anti-sway bar alone would sufficient to fix the swaying. For this situation, would you recommend the helper springs or anti-sway bar alone or both? Or should one start with one solution, see how it well it helps and then if insufficient, add the other? Anything you can add to help us understand the reasoning on using the different products would definitely help educate us! Thank you so much in advance!

asked by: Stephen W

Expert Reply:

I do have a solution to not only prevent sway while towing your boat trailer with the 2018 Subaru Outback Wagon but also prevent sag. The Coil SumoSprings part # CSS-1125R are good for leveling out the vehicle and helps to reduce body roll but are not designed to help with the sway you have described. The 19MM Subaru Outback Rear Sway Bar Kit that you mentioned may eliminate rear sway at higher speeds but it is not going to eliminate the sag.

I recommend a weight distribution system to not only help with the sag but also the sway that you describe that happens when cars pass you. The Equal-i-zer Weight Distribution System part # EQ37040ET is your best option for sway because of the 4-point sway control design. If your boat trailer is a pole tongue, you will need pole-tongue adapter part # EQ95-01-5950 to use this system. The Equal-i-zer Weight Distribution Systems are known for preventing sway before it happens because the 4-points of tension keep the trailer in line. When you tow the weight gets transferred to the rear axle of your vehicle which causes it to sag. Weight distribution redistributes the weight over both axles to stop sagging and improve handling of the vehicle. The weight distribution will solve both of your issues as opposed to just one at a time.

expert reply by: Heather A