A Bump in the Road…
Breaking an axle and skin panel damage
Coming back from the Mendocino Coast in April of 2003, we decided to go down the Bohemian Highway from Rio Monte to Santa Rosa via Occidental. This scenic trip was ended with a loud bang and the sound of tearing and scraping metal. At highway speed on a smooth road, the axle spindle had broken flush with the backing plate, and the tire/wheel assembly folded up into the wheel well blowing out the side of the skin panel as a result. Below are some pictures that document the incident and the repair. At the end is some info as to the cause of the break, and what it means to other vintage Airstream owners.
A pile of brake parts and rendered metal. The axle spindle is snapped off flush with the backing plate.
Getting an object that doesn’t want to roll up onto a Roll-Back flatbed
The frame is sitting flush on the ground on the RH side – the safety hoops on the bumper (buried in the dirt here) kept the frame from riding on the asphalt
Finally on the flatbed…
All tied down, but leaning precariously
The Airstream hospital in the redwoods…
…luckily the accident occurred near some friends who live in the Redwoods in Sonoma County. The trailer got to stay with their Airstream collection, and made the trips up to do the axle replacement bearable.
Unfortunately in the endeavor to get the Caravel back on the road ASAP, no pictures were taken of the actual axle replacement, but I have some additional axle info on a Restoration Resource page.
Replacing the damaged skin panel
Removing the skin panel
Panel cut with a hand-held pneumatic air shear. The wheel well housing is visible with the insulation batt removed
The new cutout .032 2024-T3 skin panel from Airparts drilled and ready to rivet
The Olympic Rivets ready to shave (right ones still need to be snipped)
The finished panel – good as new. The trailer now rides up good 3 inches higher thanks to the new axle. The aluminum cutout trim is available from Hoskin & Muir (pn A604T, by phone order only)
Putting a new skin panel on is also a good indication as to how the trailer finish would have looked new, using the new aluminum panel as a guide.
Look familiar? This is not ours, but another Caravel with the exact same failure..
Further Thoughts & Information
The root cause of our broken axle is one that all 1960’s Airstream owners should be concerned with. Seems the early Dura-Torque axles had spindles made from forged steel (as are most vintage conventional leaf spring axles). This steel continues to age and work harden until it fractures, usually right at the inner bearing shoulder – which was square. This is exactly what happened to us with dire results, it sheared off right at that stress concentrating square shoulder. Henschen changed the design in the late 1960’s to early ’70s, depending on axle size, to cold rolled steel, tapered bearings and a thicker spindle. The only way to tell is at your next bearing lube, check to see if you have a tapered inner bearing. So far, no one can give me any sure dates on the changeover. It only seems to occur on the 5 bolt small axle used on the Caravel, too. While the larger 6 bolt axles may be susceptible, there just doesn’t seem to be reports of it occurring.
With how much better the trailer pulls and looks, the trouble from the broken axle was worth it now. It is also an expensive way to get a bearing grease pack and new brakes too! A still good axle should have the arm angled downward with the weight on the wheels. Having just replaced the axle on our ’65 Caravel, I was amazed how much that angle is on a new axle – about 20 degrees. The trailer now sits a good 3 inches higher. (One inch is due to the change in axle bracket design.) The trailer tracks and pulls with noticeable improvement too, and I didn’t think it was bad to begin with.
The axle change went rather well. You have to drill 4 new 11/16th” holes in the frame mount brackets. The only pain is getting new shock mounts welded to the axle, as the modern ones are in different positions than the old. A welding shop did it for me for $60.
As for checking out your axle, any Airstream dealer can do that. They can also replace the axle if necessary – and they are the only ones who can order an axle for you from Henschen. Henschen is a wholesale mfg, selling primarily to OEM, and was getting overburdened by all the vintage Airstream inquiries. Their other choice was not selling individual axles at all, so this is better than nothing I guess. Cost is about $800 plus shipping ($80 from Ohio to California). The other options are a Dexter TorFlex axle and one from Axis Products, but you take all the responsibility for dimensions and specifications.
See this Restoration Resource section for more information on leaf-spring axles for older vintage trailers, and don’t forget the FAQ section.
More info & tips on the methods used here can be found in the FAQ section of the website.