I've always been suspicious about how much effect the RAS could have on wandering if it attaches behind the axle while all the consequential spring wrap occurs in front of the axle. On the other hand, my dirt track buddies fit clamps around their leaf springs behind the axle to alter spring rates.

 

If the front wraps up the rear part must wrap down.

 

The thing about the Ex's is that Ford did a 1/2 job on trying to control axle wrapping...

Those bottom anti-wrap springs do a pretty good job but ONLY under acceleration conditions...where they fall completely short is under braking conditions or when you are hitched to a trailer and the trailer is 'PUSHING' on the rear of the Ex...

The RAS effectively adds spring rate which counters the tendency to wrap.

When TOWING though I am a firm believer that most situations of 'sway' are caused by improper hitch and weight distribution setup...many simply don't take the time to tweak their hitch setup. Plus tire air pressure can adversely effect your towing stability...

I opted for the RAS simply to cure my rear end sagging due to 1200#'s of tongue weight...it also IMO benefits me from a stability standpoint and reduces porpoising when towing.

I've spent many hours at the scales though balancing my trailer setup for tongue weight as well as making sure my WD is transfering sufficient weight BACK to the front axle...

I also opted for the Hensley Arrow (very similar to Sean's ProPride) after my tweaking of the hitch setup was still not 'perfect' to my liking since I tow 12-14 hour days during our summer travels...the Hensley gave me an additional comfort factor I was willing to spend for $$$ wise...

The Ex can be a finicky tow vehicle...and one that you must spend a lilttle bit of time tweaking and balancing your hitch setup as well as your tire pressures...but once you hit on the right setup...RAS included...you are greatly rewarded as I can attest to.

I've logged just over 20,000 TOWING miles with the Ex since summer 2006...

Each mod has a specific reason to do it...but for towing applications...I suggest ensuring that your WD is setup FIRST before modifying anything...once you are sure your WD is setup properly...then you can look to attack specific sypmtoms with RAS, Hellwig, Shocks, front end evaluation, etc...

These are just my personal opinions based on personal towing experiences with the Ex so take them for that only...

Joe.

 

I agree with Joe that most of the time, an improperly setup WD hitch, or improper trailer loading will be the most likely causes for poor handeling..

I tow a fairly heavy toy hauler(10-11K+#'s), and where the loads are placed in the trailer will determine how the vehicle performs..Light tounge weight makes for a terrible experience..

We have almost 65K miles on our trailer since 04..

 

Heck, in my experience with the 285 D's I had on for 3 days, improper air pressure can create white knuckle WITHOUT towing

Only lot's of luggage in the back for our trip...
ya know, 1 duffle for me, and 5 suitcases for the blonde passenger