2007.5-2010 GMC Duramax LMM Traction Bars

What is under the back of a 2007.5-2010 Sierra HD

GMC built these with torsion-bar independent front suspension and semi-elliptical multileaf rear springs: a two-stage pack under the 2500HD and a three-stage pack under the 3500HD, with 35 mm twin-tube shocks and a 36 mm front bar on the 2500HD and 46 mm monotubes with a 34 mm bar on the 3500HD. Rear axle ratings run 6,900 lb on the 2500HD, 6,500 lb on the 3500HD single-rear-wheel and 9,200 lb on the dually. Traction bars bolt to that rear axle and to the frame. They do not change spring rate or ride height; they change what happens to the spring when the Duramax puts torque through it.

Who ends up buying them

Usually a Sierra that does more than one job. A truck that tows at its rating already asks plenty of the rear pack, and owners loading a fifth wheel or a camper on a 2500HD describe rear squat, headlights aimed high and sway. A truck on larger tires asks something different of the same spring. Traction bars are the common answer for the second case and the wrong answer for the first, because load support comes from the springs themselves or from helper springs and air bags. A traction bar will not hold the rear of the truck up.

Fixed, Recoil, or build it from pieces

Two approaches are listed here. BDS Suspension sells a fixed traction bar set for 2001-2010 2500 Duramax trucks, and a Recoil traction bar kit with its own mounting kit for the 2001-2010 chassis, which is the defined, truck-specific route. Wehrli Custom Fabrication sells the pieces instead: universal bars in 60-inch and 68-inch lengths, a brackets-and-hardware install kit for 2001-2010 Duramax trucks, and bushing and heim sets for the bar ends. The WCFab route gives you length and mounting choices; the BDS kits give you fewer decisions. Either way, the bar and its mounting hardware have to be ordered as a matched pair.

What we carry

BDS Suspension fixed traction bars, Recoil traction bar kits and Recoil mounting kits, plus Wehrli Custom Fabrication universal traction bars, bracket and hardware install kits, and bushing and heim service parts, all for the 2001-2010 6.6L Duramax HD platform that the Sierra 2500HD and 3500HD share.

Fitment notes

The bracket kit is the part people get wrong. WCF100840 is the 2001-2010 Duramax brackets-and-hardware kit; WCF100842 is the Ford, Dodge and universal kit and does not belong on a Sierra. The BDS fixed bar set is cataloged for 2001-2010 2500 trucks, so confirm the listing before ordering for a 3500HD, and confirm single-rear-wheel versus dually, since the dually body is 95.9 in wide against 79.9 in. Nothing here crosses into 2011, because that refresh brought a new frame, new control arms, new torsion bars and new rear leaf springs, which is why suspension parts for these trucks are grouped 2001-2010. And if your 2007 Sierra is a Classic, it is the previous body with the LBZ engine rather than an LMM truck.

Frequently asked questions

I have a 3500HD dually - do these bars fit?

Check the listing. The BDS fixed bar set is called out for 2001-2010 2500 trucks, while the Recoil kits and the WCFab universal bars with the Duramax bracket kit cover the 2001-2010 chassis more broadly. The 3500HD was built single-rear-wheel or dually with different rear axle ratings, 6,500 lb against 9,200 lb, so run the VIN through the fitment checker or call us and read the RPO label.

What are the bushings and heims for?

They are the wear parts at the ends of the bar, where it pivots. WCFab lists a bushing and heim set, WCF207-26, as its own item so you can refresh an existing pair of bars instead of buying a whole kit. If a set of bars has been on the Sierra for years, those are the parts to replace rather than the bars themselves.

Will a lift kit interfere with traction bars?

It can. Frame-mounted brackets on these trucks are known to collide - a Cognito pitman and idler support kit, for one, is not compatible with center-link-drop lift brackets. Tell us which lift or leveling kit is on the Sierra before you order. And remember that cranking torsion keys to level the front raises the front-end angles and speeds up ball joint, tie rod and idler and pitman arm wear, so inspect the steering while the truck is up.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.