Figure the hitch weight to select a proper hitch. Hitch weight is usually 9 to 11 percent of the trailer gross weight and should be measured with the trailer loaded. Hitches fall into 3 types: those that mount on the frame and rear bumper or the bolt-on or weld-on distribution type used for larger trailers. Axle mounted or clamp-on bumper hitches should never be used.
Check the gross weight rating of your trailer. Tongue weight is usually figured as 10 percent of gross trailer weight. Therefore, a trailer with a maximum gross weight of 1000 lbs. (454kg) will have a maximum tongue weight of 110 lbs. (45.4kg) Class I trailers fall into this category.
When you've determined the hitch that you'll need, follow the manufacturer's installation instructions, exactly, especially when it comes to fastener torque. The hitch will subjected to a lot of stress and good hitches come with hardened bolts. Never substitute an inferior bolt for a hardened bolt.