Beinkounter
Full Access Member
I recently bought a Grand Design Trailer, 30 ft, 6100lbs loaded, about 620 tongue weight. This was my first trailer and after reading up on this topic online, I considered airbags to deal with the potential sag. After getting more into the weeds of towing and WDH, my understanding was that the weight distribution hitch is supposed to transfer weight from the rear axle to the front axle. So theoretically, if you transfer half the tongue weight to the front, the weight on both axles should be the same and there should be very little sagging. If you take the time to understand how the WD hitch works and how to adjust the weight distribution feature for over/under distribution and you do it properly, you shouldn't have that much sagging even if you are at the upper end of your truck's payload limit. When the RV dealer set up my trailer, they didn't do it 100% correct because it was still sagging quite a bit and they said it was because of the truck's soft suspension. they didn't take any measurements, no scales, nothing. The tech that installed the hitch just eyeballed it. I took the truck/trailer to a CAT scale and confirmed that there was about 300lbs more on the rear axle. I could also feel it while driving with the steering being extremely mushy. When I got home, I adjusted hitch for the under distribution by adding an extra two washers (this is specific to the Equalizer Hitch), and voila! The truck was almost level, with a very small amount of sag. Much better than before the adjustment. At that point I decided there was no need for the airbags. I have yet to complete my experiment, I plan to take it back to the CAT scale next week to confirm the weight on each axle. But I did drive it on the freeway, up to 75 mph and experienced no sway and no issues and the steering was much better which indicates that the front wheels were more firmly on the ground than before the adjustment. I have heard that airbags improve the towing experience a bit from a balanced ride perspective, but you should be able to correct most of the sagging by properly adjusting your weight distribution.
