How can a bent frame be fixed?

[Eagle & Bear]

Our Airstream is a 1976 Ambassador 29’. It was in remarkably good condition when I bought it in 2006. From what I can deduce from the PO, it had less than 30,000 miles on it. I have done a lot of preventative maintenance and do routine checks on this rig. The frame is 5” channel.

We’ve put 40,000 miles on our Airstream in the past several years. We just returned from a trip to Washington DC (approximately 6000 miles). I noticed that the plates that the axles are bolted to have started to warp a bit. I inspected the plates just before we left DC and they were straight.

The plates are bowed out no more than 1/4 of an inch from the original centerline where the shocks connect to the plate. This is also the area where the plate is perforated. The street side trailing end of the plate has also started to show a slight wave like distortion (less than 1/4”). I cannot see cracks on the plate or exposed part of the frame.

I have spent several hours doing searches on bent and broken frames in airforums.com and cannot find a full set of instructions on how to do an initial inspection (how bad is it really?), what prep needs to be done, how to reshape the plate, where I can order the necessary repair parts and/or how we can do the fix on our own. Likewise, I have not found any reports of what it costs to have the repair done at an Airstream dealer.

I have placed two scissors jacks under the frame next to the rear bumper and have started the process of “stretching” the frame. Again, there are no postings that say how much upward force to apply or how far up to push the frame at the rear. In a few days I plan to heat the plate with a MAP torch and hammer it back to centerline but I do not know what technique others have used to straighten out the frame above the plate.

One of the odd things that happened when I raised the jack on the tongue (to shift weight to the scissors jacks in the back) is that the door frame has distorted about 1/2”. The door closes but the latch hits the strike plate about 3/8” lower than before and there is a gap at the top of the door. Is there that much flex in the frame? Is something else amiss?

What I am hoping to find is a link to a posting for “the fix” to this problem or guidance from anyone who has done this work on a vintage Airstream. Any information would be greatly appreciated.

Michael

[ROBERT CROSS]

Mike,

I can't offer any advice on how to repair the bent frame. But AS uses a monocoque system where the skin is part of what supports the whole.
That's why the door has sprung.
IMHO... Jacking the frame will not have the desired effect, without damaging the skin.

Bob

[marzboy]

I saw a thread recently about a bent frame. Basically they suspended the frame useing jacks under the rear and tongue. Allowing the the frame to stretch as the tires were lifted off the ground. Not sayin this will work for you, you may want to pm andy uwe frank yensen or another expert that might have a better answer. You might start by removing some of the belly pan around the area to see if you have a crack. Post some pics so forum members can have a look.

[Inland RV Center, In]

Originally Posted by Eagle & Bear

Our Airstream is a 1976 Ambassador 29’. It was in remarkably good condition when I bought it in 2006. From what I can deduce from the PO, it had less than 30,000 miles on it. I have done a lot of preventative maintenance and do routine checks on this rig. The frame is 5” channel.

We’ve put 40,000 miles on our Airstream in the past several years. We just returned from a trip to Washington DC (approximately 6000 miles). I noticed that the plates that the axles are bolted to have started to warp a bit. I inspected the plates just before we left DC and they were straight.

The plates are bowed out no more than 1/4 of an inch from the original centerline where the shocks connect to the plate. This is also the area where the plate is perforated. The street side trailing end of the plate has also started to show a slight wave like distortion (less than 1/4”). I cannot see cracks on the plate or exposed part of the frame.

I have spent several hours doing searches on bent and broken frames in airforums.com and cannot find a full set of instructions on how to do an initial inspection (how bad is it really?), what prep needs to be done, how to reshape the plate, where I can order the necessary repair parts and/or how we can do the fix on our own. Likewise, I have not found any reports of what it costs to have the repair done at an Airstream dealer.

I have placed two scissors jacks under the frame next to the rear bumper and have started the process of “stretching” the frame. Again, there are no postings that say how much upward force to apply or how far up to push the frame at the rear. In a few days I plan to heat the plate with a MAP torch and hammer it back to centerline but I do not know what technique others have used to straighten out the frame above the plate.

One of the odd things that happened when I raised the jack on the tongue (to shift weight to the scissors jacks in the back) is that the door frame has distorted about 1/2”. The door closes but the latch hits the strike plate about 3/8” lower than before and there is a gap at the top of the door. Is there that much flex in the frame? Is something else amiss?

What I am hoping to find is a link to a posting for “the fix” to this problem or guidance from anyone who has done this work on a vintage Airstream. Any information would be greatly appreciated.

Michael

The axle mounting plates are bending because they were not properly welded to the frame.

The weld on the backside of the axle mounting plate should be every couple of inches or even better.

You will find on yours that the mentioned weld area has been welded every 8 inches or so, leaving it basically not very well connected to the frame.

The bend also represents how much the shell has flexed the frame.

You can drill holes thru the axle mounting plates and the frame, then using bolts that are big and strong, rebend the plate back to the frame. Then, weld it as necessary.

If you lift the rear end high enough so that the wheels are off the ground, you will buckle and damage the 2 rear quarter panels, permanently. Don't do it.

Andy

[Eagle & Bear]

Thanks Andy.

The welds between the axle mounting plate and frame are sparse. The axle mounting plate seems wholly inadequate but it lasted this long.

I jacked the rear frame up high enough to close the 1/2" rear separation gap. There is no distortion of the sheet metal.

I can do the drilling but will have to take the trailer to a frame shop for the welding.

Michael

[Inland RV Center, In]

Originally Posted by Eagle & Bear

Thanks Andy.

The welds between the axle mounting plate and frame are sparse. The axle mounting plate seems wholly inadequate but it lasted this long.

I jacked the rear frame up high enough to close the 1/2" rear separation gap. There is no distortion of the sheet metal.

I can do the drilling but will have to take the trailer to a frame shop for the welding.

Michael

The rear end separation is an entirely different issue, and it has nothing to do with the bent axle mounting plates.

Repairing rear end separation, depending on how far it's gone, can be easy up to extensive.

There are many posts in this Forums regarding correcting that separation.

Andy 12.4+2

[Schu]

The Service Center at Jackson Center has a frame stiffener kit available that can be added.We would straighten frame as needed and install stiffeners.

[Eagle & Bear]

BIG Surprise!! I have been working on bending the axle mounting plate back into place. After pulling the belly pan back I found a crack in the lower horizontal part of the frame. It goes through the 1 1/2 inch lower part if the frame rail and extends about 1/2 inch up the face of the frame.

Can I weld metal reinforcing plates onto the frame and expect a good outcome?

What kind of material should I use and how should it be welded on?

Do I need to put a frame stiffining kit on?