For my L4310HST, I use 3/8" chain through the loader subframe tube in the front and throuh a shackle mounted to the drawbar for the rear.
As was mentioned, balance on a trailer is critical. You don't want too much weight on the rear axle of the towing vehicle, but whatever you do, don't underload it either - if you do, you run the risk of everything seeming fine until you get up to a certain speed, where progressively violent oscillation begins, which can quickly become bad enough to make you lose control. If this ever happens, don't brake using the tow vehicle's brakes - use your manual braking button on the brake controller to apply trailer brakes only, which will tend to stop the oscillations and pull the combination straight again.
Mark