Tightening the Front Torsion Bars

Original Project Date: April 2006

Project Summary:
I explain how I level the H2 front to back.

The front end on my H2 had always been a little bit lower than the front. At first, I liked it this way, but it began to bothering me. It was about 16 inches to the bottom of the rockers in front, and just over 17 inches to the bottom of the rockers in the rear.

The H2 has an independent front suspension that uses torsion bars to provide upward force on the lower suspension arms, thus setting the ride height (and firmness). When you can tighten these torsion bars it raises the front ride hight.

I tightened the torsion bars on each side. On the passenger side about 4 turns and on the driver side about 5 turns. Each turn results in about 0.2 inches in ground clearance at the front differential.

I never measured the difference in height at the front differential or the front bumper, but I did bring the front and rear lower edges of the rocker bars withing 1/4 inch of eachother on each side.
I’m guessing that I obtained about 1.25-1.5 inches more of clearance under the front differential and skid plate, which obviously is important on an independent front suspension vehicle if you take it off road.

Caveat #1

Whenever you make this sort of adjustment, you are changing the camber alignment of the front wheels. So you need to get it aligned soon after making the change. It’s recommended that you wait until driving about 50-100 miles before doing the alignment to allow the front suspension to "settle" into where it wants. It certainly doesn’t hurt to drive over some rough dirt roads to accelerate this proces :).

Caveat #2

As I mentioned above, tightening the torsion bars will not only change the height of the front end, it will also increase the firmness of the ride. Some people will find the ride too harsh. I personally prefer a stiffer front end.

Caveat #3

You can be overzealous in trying to obtain increased ride height. If you tighten them too far you limit the ability of the bars to dampen the suspension arms through their full range of movement. On a recent wheeling trip, I noticed that I’d hear lound clunks frequently from the passenger front corner whenever coming down on that wheel in ditches. We straightened out all the undercarriage protection and made sure all the bolts under there were tight, and still it would clunk.

A couple HUMMER techs and I all concluded that the right torsion bar is probably a little too tight. Nothing that will result in a chronic wear problem, but rather just something that’s going to clunk a lot when a lot of weight is put on that corner while wheeling off road. Next time I plan to get rotate and alignment, I’m going to back off the tightness on the torsion bars a turn or so and see if that makes a difference on my next wheeling trip.

Before and After Pictures

I set up a camera on a tripod to take a picture before and after the change without moving the truck. This allowed me to make the following two pictures.

Picture #1 - Composited before and after picture

Picture #1 – Composited before and after picture. The difference between before and after is most readily seen in the lines of the front door edges.
Picture #2 - Before and after pictures animated in a loop

Picture #2 – Before and after pictures animated in a loop.

Conclusion

If you have a torsion bar front suspension and they’re not already too tight, there’s an easy way you can adjust them to raise, or lower, your front end a little bit to improve appearance of your vehicle when viewed from the side, and maybe even gain a little bit of front end clearance over off road obstacles.

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2 Responses to Tightening the Front Torsion Bars

  1. Rick says:

    Good explanation. I just put a 38x 14.00 tire on my h2 and im only getting about 15% turn wondering if this would help

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