A double axle trailer typically has trailer brakes on it and will need either a 5, 6, or 7 pin connector, not just a 4-pin which is most common. The piece of plastic that pops out is located on the bumper and would not be ideal for towing this heavy of a trailer. I would guess that this trailer is capable of 8k lbs and probably weighs 1500 empty, putting about 600-700 lbs worth of tongue weight on your hitch, which is more than is recommended for your bumper. Additionally, I would guess that your trailer requires a 2 and 5/16 inch ball for that trailer, whereas most lightweight trailers require only a 2 inch ball. Please correct any of my assumptions.