Update 2006 Rockwood Frame Bending
I am finally getting around to these repairs:
The frame on my 33 foot rockwood bent because:
1) It is built light; 9/64 inch thick x 2.5 inches wide x 6.5 inches tall.
2) It overhangs the rear axle by 11.5 feet.
3) This area holds a rear bedroom with a slideout and a bathroom.
4) Both 60 gallon waste water holding tanks are mounted underneath.
I earlier posted that I put two 8000 lb axles under this trailer (16 inch tires 8 bolt lugs) because I was burning out bearings and blowing tires. This trailer weighs over 7000 lbs empty and had 15 inch tires 5 bolt lugs on 3500 lb. axles. Some people speculated the bending was caused by too heavy of axles. However after checking with Dexter these 8 bolt Dexter rubber torsion axles #58632 with ST235/80R/16 tires, larger spindles, brakes, hubs, bearings, and heavier axle tube are also only rated at 3500 lbs/axle. So other than larger bearings, (no bearing failure since) larger tires, (no tire failure since and tires are E rated at 3500 lbs. each) and heavier axles I guess I didn't gain anything as far a suspension goes. I find this hard to believe but this is what the Dexter factory told me after looking up the part number.
I am not able to box in the frame or strengthen it in any substantial manner as the driver's side slide out supports come across the underside of the trailer and attach to the passenger side frame right in front of the forward rear tire. In order to continue using the trailer I purchased another #58632 axle and will be mounting just behind the second axle making the trailer a triaxle. I can extend the 8" x 3/16" x 2.5" axle support beam 5 ft behind the one mounted under the trailer frame in the same way and weld it to the frame and the existing axle carrier 8" box. This will leave only 5.5 ft of trailer overhanging the rear third axle support. The frame had bent right at the original rearmost axle support and by blocking the front of the trailer up and jacking the rear frame just in front of the rear bumper on both sides, with the axles hanging in thin air the frame now appears straight again. I will box the existing area on both sides where the frame had bulged out with some 1/4 inch plates also. Granted the trailer will weight a little more and the tires will skid when making extremely sharp turns but overall I think this is my best option and I will gain extra carrying capacity and another set of brakes. I will post some pictures as this project develops.
As far as the sagging floors go, I have removed belly cover as I thought I would have to shore the floors up from underneath as well work on the top side. When I opened up the top side under the vinyl I found that the deck is a prefabricated floor system of 1/4 inch luan plywood on top, glued to 1.5 inches of styrofoam with 1/6 inch fiberglass cloth glued to the bottom. There are however (good news for me) 1.5 inch square aluminum tubing sandwiched in this system 16 inches on center extending to both sides of the trailer and also of course sitting on the frame. Over time the area between the aluminum supports sags down about 1 inch as you step there because the bonding has broke between the luan and the styrofoam.
I have ripped out all of the vinyl, carpeting, and luan plywood in a couple of areas where it had been wet. (floor area in kitchen by closet that holds water pump had leaked for a while at one time) Also the front bedroom had rotten floors from water coming in where the front corner broke loose, water coming in the baggage compartment doors that have been left open in the rain at times, and from who knows where else. I was able to remove the luan in this area right down to the aluminum and styrofoam. I will sheet this floor with 3/4 inch treated t&g plywood and cover the rest of the floor where the 1/4 inch luan is still good with 1/2 inch treated plywood screwing to the aluminum supports. I am going to install a floating locking vinyl waterproof plank flooring system throughout the trailer including the floor of the larger kitchen slideout. I appears that the slideout will come up over the 1/2 inch plywood and new flooring. I will also post some pictures of this as it develops.
To Be Continued Later. Thanks for your interest.