Start at a moderate setting (5–6 out of 10) and test. At 25 mph on a clear road, apply only the trailer brakes. If the trailer skids, reduce gain. If the truck does all the braking (trailer pushes), increase gain. The ideal setting produces smooth, proportional braking without lockup.
- Light trailer (under 3,000 lbs): gain 3–5 depending on load
- Medium trailer (3,000–6,000 lbs): gain 5–7
- Heavy trailer (6,000–10,000 lbs): gain 7–8
- Very heavy (10,000+ lbs): gain 8–10, consider disc brakes
- Adjust gain every time the trailer load changes significantly
| Trailer Weight | Tow Vehicle | Suggested Gain | Terrain Adjust |
|---|---|---|---|
| 2,000 lbs | 5,000 lbs truck | 3–4 | +1 for hills |
| 5,000 lbs | 6,000 lbs truck | 6–7 | +1–2 for mountains |
| 8,000 lbs | 7,000 lbs truck | 7–8 | +1 for steep grades |
| 12,000 lbs | 8,000 lbs truck | 8–10 | Max for downhills |