Thanks for your replies everyone. Keep in mind that the back is not the only place with things being loaded and stored. I already have about 500 lbs of solar panels, electric, sewer, spare parts, outdoor propane stove etc. etc. that is in the basement up front. That still leaves 1200 lbs available for personal things and kitchen stuff, doubt I'll even come close on it.
I've decided though from some of the comments that it would be better to not mount the generator on the bumper. Going to have the box with slides in the bed of my truck, carriage bolted to the bed. I already have a trailer tongue tool box back there right behind my hitch, so the generator at the back by the tailgate would be just as convenient. Easy access to connect to 5ver and could use it to jump start someone if needed. And no added impact to the pin weight.
As far as "voiding the warranty" goes, doesn't concern me much. "Pro Bono" Johnny, my lil brother will remind the dealer and the manufacturer of the story about the lady that bought a new high end Class A. After driving it off the lot and onto the highway, she brought it up to speed and set the cruise control. Then proceeded back to the kitchen to make herself a sandwich.
We all know what happened don't we?
Jury awarded her $4 million in damages because nobody told her that the thing didn't drive itself. Just never know what 12 idiots on a jury might do.
There is nothing in any documentation, owners manual, dealers paperwork etc that SPECIFICALLY precludes installation of a hitch receiver for use with carrying a motorcycle/ramp.
And there is nothing that has my signature on it that has anything like that mentioned. Matter of fact my dealer gave me the name of the shop that they use often for hitch installs on TT's and %vers. My friend did it for half what they were asking, with a higher cargo capacity. As he has been in the business for 30 years and has installed on 4 of his own 5th wheels, I'm pretty sure there will be no problems with "warranty" issues.
