Builder,
Ask all the questions you want to, I'll try and answer them.
Yes ...my New Holland TC-45D with 16 LA front end loader and 757-C backhoe will fit in my 7 x 14 dump trailer. I also thought I needed a 16 ft trailer to haul my tractor. Some of the trailer companies will not make a 16 ft trailer with the 7K axles, you have to move up to the dual tandem 10K axle. I know PJ, Load Trail and Br-Mar don't. But All-Pro and Texas Pride do.
The way I load my tractor is to have the tailgate in the barn door configuration. I raise (dump) the trailer slightly so the bed is approx. 12 to 18 inches off the frame at the very front of the trailer. Drive tractor in FEL first with FEL raised so it goes over the gooseneck frame of the trailer. With the backhoe installed I have to swing it all the way to one side to keep it from dragging on the ground as the front tires of the tractor go up on the ramps. This is not a problem with a box blade, or scraper blade. Drive the tractor all the way forward until the brush guard just touches the front bulkhead of trailer. At this point I always shut the tractor off and make sure it's in gear with the parking brake set securely. Be careful here because the dump bed is tilted up and the tractor could roll backwards. Lower the dump bed, close tailgate, and stow the ramps. Start tractor and back up until backhoe bucket just touches tailgate, this leaves about 18 inches between brush guard and forward bulkhead of trailer. Lower FEL down on top of gooseneck frame. Shut engine off again and cycle FEL joystick thru all positions several times so FEL is complely resting on gooseneck frame with no preload from trapped hydraulic pressure. Chain tractor down, and I always chain the FEL down. This procedure has the FEL and bucket resting on top of the goosneck frame. This works well for me. I have asked my county sheriff and the Georgia DOT inspectors about this configuration. They say It's legal as long as the FEL is supported by trailer frame, and it is tied down. If you want your FEL and bucket flat in the dump bed it will not fit in a 14 ft. trailer. It will fit in a 16 ft. trailer but you can't have any attachment at all on the tractor. Also even my small 5 ft bush hog, or disck harrow, will not fit in my 14 footer because they are too long.
Sorry I don't have any pics yet. If I can get all that junk to the scrape yard Thursday I'll see if I can get some.
If you have more questions let me know. I shopped for my trailer for 3 years. Think I wore a Stanley PowerLock measuring tape out trying to figure out how things would fit.