How To Help With Rear Sag While Towing With a 2007 GMC Envoy and Quality S WDH

Question:

My second hand trunnion bars are part of an older WD hitch that I bought used, so dont know what the bars tongue weight holding is but they are about 28 and3/8inch or so long, and the end with the knuckles measure about a 4.25inch from top to bottom bolt/knuckle thingy. Ive tried almost every height on hitch head , several tilt angles on head, and still had both flexing bend on bars as well as tow vehicle with about 2inch squat in rear. This is with 4 chain links hanging, most settings had me hiking the travel trailer quite high up in order to even fit the chain on the snap up hook on chain hangers, so was feeling tremendous force load that concerned me something might snap. Can I be correct that the trunnion bars are too weak, so are flexing and giving way to tongue weight, becoming a weak link ? Otherwize , might it be my 2007 envoy denali 4wd needs stronger springs, spring lift/helpers, ext ? I did put new shocks all around envoy less than 2 years ago, but didnt think about rear springs as I do not have rear end height problem without trailer. What is least cost solution ?

asked by: Mike M

Expert Reply:

It does sound like the spring bars that you have are underrated for your trailer which is then not allowing the tongue weight to be transferred to the front of the tow vehicle which results in too much sag. As we do not carry the Quality S Weight Distribution System, I unfortunately would not have the correct replacement spring bars for you nor am I aware if they are even available.

That said, the most cost effective option you have to help get rid of the sag would be to use the Firestone Coil-Rite Air Helper Springs part # F4108. These are super easy to install and they are adjustable. In order to use these with a weight distribution system, all you need to do is set the air pressure and then attach the links on the spring bars. This will take tension off of the spring bars so they will then not have as much pressure on them so you don't have to worry about them being underrated as much and causing a break. That said, you may not even need your weight distribution system if the sag is gone once the airbags are installed.

expert reply by: Conner L