Wannafbody

I've noticed and read of others who've noticed that these trucks are sensitive when towing. On occasion I'd get a little wiggle on cornering or going over bumps. I'm sure that this is due to the nature of the suspension compressing before engaging the overload spring. What I did was pop out the rear overload spring rubber pad and replaced it with Energy Suspension bump stop 9.9132G with .375 inch height(this is shorter than the 11/16th one that others have used). The rear of the overload spring engages slightly faster for less of that squishy feeling from the back. The ride has become firmer and just a slight bit harsher over really big bumps but I think the tradeoff is worth it for the stability.

king nothing

Any effects while not towing?

Wannafbody

I initially drove with the thicker bumpstop without the trailer attached and it rode OK but decided to try the thinner bumpstop instead. The thicker one was a bit harsher over bumps unloaded as it was touching the spring at all times. The thinner bumpstop has a bit of air between it and the spring even with a 3000# trailer attached so unloaded it should be fine. It's a 10 to 15 minute install and uninstall should you dislike the ride quality.

The easiest way to install these is to leave your trailer attached and use the trailer jack to lift the rear of the truck high enough to slip the bumpstop between the spring and overload spring.

Also I compared springs with my 09 Z71 and the overload spring pads are about 2x as thick as the pads Ford uses on the F150.