@traildogck has been working on those problems.

with custom bushings.

 

The stock bars need no lateral locks. WhiteLine Bars are wider, and need the collars they include.

If you have extreme lateral movement, I would suspect struts, or control arm bushings...

As always CKE SSP sway bar bushings are the ( . )( . )s

https://www.subaruoutback.org/forum...arts-accessories-performance/458146-subaru-specialty-products-tdck-cke-ssp.html

tdck has you covered

 

Nope no rib or anything to keep the sway bar from sliding side to side. It should almost "self center" due to its own geometry AND being tied to both sides of the rear or front suspension. Traildog is right, if it doesn't self center than there is something going on with the lateral links. I am not sure that the sway bars are associated with clunking though. How many miles are on your OB?

 

103,000 miles on it. Never seen off-road. Got it for the ground clearance in the snow.
Thought maybe the curves in the bar were to prevent lateral movement, cus the end links would otherwise allow a lot of migration.
I know the bushing squeak at both ends cuz I heard them and felt the slip-stick by touching the bar with someone else bouncing the suspension. One link in the rear makes noise and I can see movement in the ball joint at on end of the link. Figure the others aren’t far behind, so if I gotta go under the car (again), I’ll change them all.
This car has been maintained immaculately by a former aviation mechanic and mechanical engineer (me).
Another CV boot is torn, too. Replaced 2 years ago, with OEM reman axle. Wish someone made a double-cardan type drive axle.

First and last Subaru, ever.

 

Did you swap out struts /shocks yet?