Good day,
New to the forum but wanted to ask a question that is stumping me. I have a 2007 Hummer H3 with approx 130,000 miles on it. I have cranked the torsion bars to level the front of the vehicle (added increased length shocks in the front), put on 1/2" extended shackles in the rear leaf springs, and had an alignment done.

Recently I noticed the rear passenger side suspension appeared to be sagging. When measuring from the center of the axle/hub to the bottom of the plastic trim in the wheel well, I noted my H3 was sitting 1" lower on the rear passenger than the rear driver side. Due to the age/mileage, I assumed my leaf spring on the rear right was getting tired and starting to sag. I bought OEM replacement springs for both sides and installed them a few days ago. To my dismay after dropping the H3 back down, the same 1" sag on the rear passenger side is still there. All suspension components are properly torqued and the front end is sitting level.

I'm stumped on what the issue is. When I pulled the CARFAX report when I bought it, there was no issue of any accidents on the vehicle so I don't believe the frame is twisted. I can provide actual measurements of wheel clearances if needed. Any thoughts on this would be appreciated.

 

Welcome to HF.

The key question is what was the across the rear measurement before the shackles (that ain't even talking about the why)? If you over-tightened the shackle bolts, you can bind the spring causing one side to settle lower than the other.

There was an old TSB on this because new H3s delivered at dealerships after shipment by truck and rail some times had your problem. In a nut shell, what it said was loosen the shackle and spring bolts, jounce the rear suspension a bunch of times (Bumper Monkey) and then re-torque the bolts, drive and re-measure, repeat if necessary.

Good luck.