Rear frame plate

[15YearsAfter]

Looking for some guidance about replacing the rear angle attachment for my 1970 Overlander. The majority of existing material that came out has disintegrated considerably. I have seen the basic idea of what should go back, but am wanting to know what about replacing the angle with aluminum, would that be strong enough ? I have seen someone use stainless, well maybe, or is a well painted steel piece the way to go ? Any other input as far as the rest of the pieces that tie the rear structure together would be GREATLY appreciated.
The trailer is gutted, floor is out, interior skin out. I have made new sections for the rear 3 feet of main frame and angle support underneath. I am planning to bolt 2" wide x 1/2 " steel channel from inside and underneath through the top leg of frame through the floor and to the aluminum c channel. This will leave room for 1/8 " angle attachment to sit flush under new floor. Wanting to do this right, hoping to hear from the vast amount of knowledge out there !

[Inland RV Center, In]

Originally Posted by 15YearsAfter

Looking for some guidance about replacing the rear angle attachment for my 1970 Overlander. The majority of existing material that came out has disintegrated considerably. I have seen the basic idea of what should go back, but am wanting to know what about replacing the angle with aluminum, would that be strong enough ? I have seen someone use stainless, well maybe, or is a well painted steel piece the way to go ? Any other input as far as the rest of the pieces that tie the rear structure together would be GREATLY appreciated.
The trailer is gutted, floor is out, interior skin out. I have made new sections for the rear 3 feet of main frame and angle support underneath. I am planning to bolt 2" wide x 1/2 " steel channel from inside and underneath through the top leg of frame through the floor and to the aluminum c channel. This will leave room for 1/8 " angle attachment to sit flush under new floor. Wanting to do this right, hoping to hear from the vast amount of knowledge out there !

There is a drawing somewhere in this Forums, that shows you how to add more "holding" strength between the rear shell and the chassis.

Keep in mind, that the shell holds up the chassis, and the more fasteners between those two, the greater the strength.

That will avoid another rear end separation.

Andy

[barts]

It seems to me that the weak areas in the original design are as follows:

1) the horizontal support for the bumper storage area lid goes underneath the plywood; this leads water directly to the plywood
and causes rust between the frame and plywood. Rust attacks wood very quickly.

2) The angled metal rear plate that goes underneath the plywood and bends up between the C channel and the rear skin is steel. This steel is wet and in contact with aluminum; this cause dissimilar metal corrosion.

3) The angled metal rear plate is not fastened to the skin except by the rivets holding the skin to the C channel. This is unlike the front plate, which is held by a row of rivets in the skin as well.

So, I attacked the above by:

1) replacing the badly corroded steel angle plate w/ stainless
2) adding an additional row of rivets near the top of the stainless plate
to better secure the skin to the frame. Since the rear panel appeared somewhat weakened next to the C channel due to corrosion from inside, I added an internal doubler of 6061 aluminum between the skin and the stainless plate... I could have replaced the rear panel, but that was a bigger job than I had time for....
3) removing the bumper lid support so that water no longer is led underneath the plywood, and thoroughly caulking everything w/ Vulkem.
4) replacing all the rusted bolts with stainless w/ Nylock nuts...

- Bart

[15YearsAfter]

Thanks Andy, I will keep in mind the support of the shell in the connection to the chassis, like suspenders eh ? I have added two additional outriggers closer to the aft end for additional support, similar as are located in the fwd end. I will keep looking for the drawing you speak of.
Bart, I like your game plan, and was thinking along those lines as well. Thought of adding a sheet along the entire width of the rear panel under the hatch that ran down far enough to divert water below frame level. I would have to seal carefully the black tank line where it penetrates through, but no water getting to the floor. So, no dissimilar wet metals, and extra fasteners and lotsa sealant !

[Inland RV Center, In]

Originally Posted by 15YearsAfter

Thanks Andy, I will keep in mind the support of the shell in the connection to the chassis, like suspenders eh ? I have added two additional outriggers closer to the aft end for additional support, similar as are located in the fwd end. I will keep looking for the drawing you speak of.
Bart, I like your game plan, and was thinking along those lines as well. Thought of adding a sheet along the entire width of the rear panel under the hatch that ran down far enough to divert water below frame level. I would have to seal carefully the black tank line where it penetrates through, but no water getting to the floor. So, no dissimilar wet metals, and extra fasteners and lotsa sealant !

The drawing I mentioned is under "The best way to fix this".

It's post # 14 dated 7-16-2010

Or you can go to "SEARCH" and enter rear end separation.

Andy