Comparing Timbren Kits GMRCK25S & GMRCK15S for 2003 Silverado 1500 ZR71

Question:

I am confused on the vehicle fitment. I have a 2003 Silverado 1500 ZR71 extended cab. Which Timbren kit do I need? I am hauling a travel trailer, and want to avoid the rear sag.

asked by: David B

Expert Reply:

Timbren kit # TGMRCK25S fits the 4WD version of your Silverado 1500LD while kit # TGMRCK15S fits the 2WD version. These kits provide progressive resistance when under load to help stiffen and support your OEM suspension, especially useful for cargo loads in the bed, but they do not add weight capacity to the vehicle.

Rear-end sag from pulling a travel trailer is best handled by a weight distribution/sway control system rather than a set of jounce springs. A properly-tuned WD/SC system will correct the rear-end sag (and your headlights pointing up) while also helping to prevent trailer sway from passing vehicles and wind gusts.

The key to choosing a WD/SC system is to know your fully-loaded trailer tongue weight (TW), which includes the weight of anything in the bed behind the rear axle. The linked articles explain ways to do this and also address the basics of WD systems and how they can correct the sag problem.

I also included a link to our main page for WD/SC systems where you can click on your total TW figure to see systems with the correct stiffness to correct the rear-end sag. Please feel free to let me know your total effective TW figure and the type of brakes on your trailer and I can offer recommendations.

expert reply by: Adam R