If the vehicle rides rough empty, the rubber spring most-likely touches the axle.
The recommended gap between rubber spring and axle is ½” – 1 ½” empty. Measure the gap if you’re not sure.
In either case, the fix is fairly simple:
- Remove the Timbren SES kit from the vehicle.
- Measure between frame and axle when the vehicle is level and unloaded.
- Call customer service. Explain the problem. Be sure to give them the measurements.
- Depending on your measurements, they might recommend a different size spring or bracket. And, in some cases, a different kit altogether.
Also, a partial load (like a 200 lb. truck cap) can make the suspension deflect on bumpy roads, causing the rubber spring to make partial contact with the axle.
If the original suspension deflects more than an inch unloaded, you may need to lift the frame and/or stiffen the suspension.
This can be done by adding an additional leaf to the spring stack or by re-arching the springs.