Frame Flex as Designed

[Wabbiteer]

Andy once said torn/broken outriggers and/or broken tie-down bolt problems would telegraph the increased oscillations to focus elsewhere for popped interior rivets on the far side - he also said a frame quick-check on a vintage exterior shell was site down an aft-to-front view across wheel well openings; 5/8"~ bulge at the skirt of shell aluminum flex-out said to be normal frame/shell bending - more than that is clue reveal of frame problems. Oh, yeah, that is on top of his Mantra about unbalanced running gear - tire/wheel/drum not trued as a unit - accelerating & exploiting every type of weakness imaginable...

[dbj216]

Hi Wabbiteer from a former Minnesotan: The body of our Sovereign looks pretty good. I did check for buckling of the body side panels and didn't find anything alarming. But the axle plates were buckled, and both frame rails sagged from the rear axle notch to the rear. I've tried using trailer weight to straighten them to no avail. I have the trailer supported just forward of the entry door (both sides) and at the rear with nothing in between. It is a 20' bridge so to speak. But the rear frame rails will not level out. It may be the stiffeners we have already welded in place are preventing any further movement of the frame rails.

It ain't perfect. Get used to it.

David

[knowmercy]

Hello again. Hopefully this isn't "free, unsolicited advice on the internet" but I wanted to offer up a friendly suggestion. In the past when we've had plate steel with waves in it like that, we've had good luck with cutting slots along those seams, then moving the steel where we want. We'd lift the end of the beam, tap the plate "straight" and then re-weld the seams. This looks like a good candidate for some additional angle iron after you re-weld the seams as well. Again, I'm not trying to tell you anything you don't know... just a suggestion. Cheers again! Excited to see how this turns out.

[Minno]

We had about 3/4 inch sag at the rear of our trailer - enough to squeeze in our 3/4 inch plywood subfloor pieces in between the frame and trailer as we replaced them in the rear. Inland Andy said that was a very acceptable gap. Replacing the subfloor made a HUGE difference in the feel of the frame and subfloor when walking on it. It's SOLID. We did replace a few outriggers and strengthened the frame where it had rusted. Our new grey tanks are between the axles, black tank is at the rear where the bathroom is.
Adding an Air ride hitch set up reduced the "shake" the trailer was getting going down the road, as we now go into the trailer after towing and have nothing out of place, even on bumpy roads. It is heavy, though, at 95lb. (And the hitch wasn't cheap either). Worth the cost to us.

Kay

[Wabbiteer]

Ripple on the vertical axle load plate just plain out & out looks scary - I've kidded about 'Dukes of Hazard' jumps before but that there is evidence of mild iron that's been surfing some black holes singularity event horizon! Cutting to level out those 'pleats' must've been satisfying!

On the ain't perfect realm - Amen...

[perryg114]

Some waves in the axle mounting plate are where shop monkey's miss the plate with the jack and hit the shock mount. They are also hard on tank pans.



Perry

[dbj216]

Thanks showmercey for the tip on correcting buckle in a thick piece of sheet steel. I'm sure that would work fine.

Gee Kay, only 3/4" sag with the rear of the body disconnected. I'd be real happy with that. We had about 3 1/2" of sag with the body disconnected. I don't think we will get it all back perfectly straight again, but it is a heck of a lot better.

We used BIG c-clamps and pulled the axle plate sheet straight after we got it good and hot. It did a good job of straightening it. We didn't burn "up" the Airstream or burn "down" the shop with all that heat thank goodness.

Airstream didn't do just a great job of welding this axle mounting plate to the frame rail on our trailer. It is stitch welded on the lower flange in back, and stitch welded about every third stamped hole in the front. It is also stitch welded on top of the axle plate in front. We improved that considerably with some big angle irons under the frame rail lower flange to the bottom of the axle plate.

There certainly have been both shop and owner inflicted damage to an Airstream trying to jack it up. The axle tubes get the brunt of it, but jacking through the belly pan has certainly happened too. Airstream ought to have a "place jack here" detail on the axle plate so we know where to jack to change a tire.

I think with rear end separation the frame rails are free to flop around as we bang over rough bridge abutments, or potholes, or scrape the rear on a steep fuel stop entrance ramp. Out of balance wheels can cause some significant vibrations too. The rear frame rails get bent, buckled, cracked and otherwise distressed without the body holding the rear of the frame in position.

David