Couplemate’s combination pintle hook receiver arm is a one-piece 50mm receiver arm.
There are real savings to a one-piece towing system. Fits into a 50mm tow bar box section or pintle hook mount. Note: Hitch pin is not included with this product.
Please note NHVR states from 1st September 2017, 50mm tow balls de-rated to 2000kg when connected to tow vehicles 5t and larger.
Remember to take care when reversing. Angles greater than 80 degrees will cause the trailer and coupling to jackknife.
Well, I installed the pintle hook and ring coupling equipment as you said and within one month this equipment is ruined and likely to cause an accident.
Unless you really know your trailer there are various answers, all of which are pointing towards the customer.
The most likely cause of equipment malfunction is a jackknife.
Question: Is your 50mm tow hitch rattling?
Answer: The solution is a high tensile pin.