Sbowmanok

Yes, I am using an 'Equilizer' brand hitch. Formally pulled the trailer with a '19 RAM 1500 and did not have this issue, traded truck because it didn't have enough horses for this trailer. This Sierra 4x4 at stock height was 'porpoising' on it's maiden pull, would like to get this corrected, looking for recommendations.

My problem is not sag, I am get a seesaw effect when hooked to the trailer on roads with waves. I am looking for a strong shock to stop that effect.