Move the weight backwards a wee bit (the pic looks a little front heavy with a lot of tongue weight for your LD truck), chock the tractor wheels, make sure the loader is in its lowest position and can't move (make the bucket flat or all the way forward, not in the middle). Get wider straps than 2 inch and make sure they ratchet properly and the tractor is snugged down tight. Don't waste money on uncertified cheapo straps. If the straps are failing for no reason then throw them all in the garbage and switch brands asap.
What's your tailer and tractor weight?
What's your tailer and tractor weight?