Remove shell '78 Ambassador

[CustomShop]

Hey all,

I have searched here, after noticing a disturbing lack of archived and sticky'd information compared to most forums I've been to. I can't find a step-by-step, procedural guide for removing my shell. It's not obvious how I brace, and where all the hold-down plates are, etc.

Anyone have a comprehensive thread on this handy from around this time period? My subfloor needs done, need to weld in some new outriggers, and getting this shell up and off would be dandy.

I have to remove the screws around the perimeter, and what look like nuts on bent carriage bolts - this much is clear. The banana wraps are down, Belly pan too, and the interior skins are off. Elevator bolts have been hole-sawed around. Looking for some professional advice.

Thanks

[Lance M]

Sound free advice, or professional advice? Normally professionals are paid for their services, that's how they make a living and pay the bills.

Here is a list of most of the major threads of the last 12 years or so. Lots of free advice in these threads.

http://www.airforums.com/forums/f44/...ons-35399.html

[Belegedhel]

If you are going to pull the shell, then I recommend building a pair of gantries, lifting the shell and placing it on the ground, and then move the gantries so that they can be used to lift and flip your frame. This way, as you scrape the rust off the frame, repair and repaint it, reinsulate the floor, replace axles, reinstall belly skin, retrofit tanks, etc., all can be done by lifting and flipping the frame, rather than lying underneath it and getting a face full of junk with every operation.

Have a look at the following thread for some shots of what can be done with the shell and frame separated:

http://www.airforums.com/forums/f36/...on-115765.html

As far as a step-by-step, the "full-monty" threads referenced above are a good source of examples of how others have done it. The good news is that as far as disconnecting the shell from the frame/floor, it is pretty intuitive. As you dismantle the trailer, you will see the fasteners and can identify wht needs to be drilled out in order to free the shell. Lifting the shell is technique sensitive only from the point of view of the mechanism of the lift. As mentioned immediately above, I view the gantry lift as the simplest method. If you do a google search for "gantry airforums" from outside the forums, you should find links to several threads where a user used a gantry frame to pull the shell.

good luck

[dbj216]

By the way customshop, welcome to Air Forums! You're 78 Ambassador is a large Airstream. Should have plenty of room for comfortable traveling. It's probably a California trailer that hasn't been ravaged from moisture. These forums talk extensively about frame rust and rear end sag, especially on the 70s trailers. You are wise to take it down to the bones and rebuild the weak spots.

Maybe you would enjoy starting a full monty thread in the 78 Ambassador section of the Knowledgebase. I'll bet you would garner quite a following as you progress down the disassembly and then back up the rebuild.

David

[perryg114]

Does it need a shell off?

Perry

[CustomShop]

Thanks for the warm welcome guys

We plan to live in this airstream for some years, so I'm going over the whole thing. The frame has some outriggers in the rear curbside that need replacement, but otherwise all I can see looks pretty good down there. I will be applying POR-15. How do I know if I need axles? The trailer pulls great and towed well for about 4 hours back from Sausalito. Shell is in EXC condition, so it's worth the restore. It will also be easier to work with the subfloor which has suffered some serious rot if I have the shell off.

I plan to brace the frame of the shell [which I could use some help with], jack it up and set it on to elevated boards like I've seen. The gantry seems too intense. We're living off grid far from town in another trailer, which we're renting. Trailer is on-site, but fire-danger prohibits some work, and it's out in a mowed spot below a meadow. We're working with what we got.

I found a great thread showing the hold down plates, which was really what I was looking for. I think that kind of advice should be free. I get that some people make their living doing this, but the appeal is in the convenience, not necessarily technique. I bet a lot of those guys learned what they know on here for free.

[nrgtrakr]

Axles here ...
http://www.inlandrv.com/articles/dur...xle-92001.html
Our new to us 75 has the original axles, the angle is still slightly positive and the drop when raised is 2". We've yet to tow it loaded, so won't know for sure how "bad" it is until loaded. Original plan was winter in Texas and change axles there (currently in Colorado), but we're flexible even if the axles may not be.

[morganobenn]

I am a strong proponent of the chain hoist gantry approach.
I used 12 ft length 4x4's for the legs and span across the top. I recommend bracing the joints with 3/4 inch plywood triangles with 4 ft sides; use one on each side (so four triangles for each gantry -- one sheet of plywood). The legs join to a 6 ft long 4x4 foot that rests on the ground -- but I extended the length of the feet using 2x4's to 12 feet.

I used the 1/2 ton chain hoists from Harbor Freight.

I made a ribs from 3/4" plywood (three ribs for my 22' Safari) to match the curvature of the shell and attached those to a beam running the length of the shell -- end ribs just before the bullnoses. The chain hoists joined to eyebolts in the beam. I ran the chains through the vents (they will need replacing anyway).

Before I removed the shell, I made a frame of 2x4's by attaching one length to each side at where the floor was joined to the shell. I ran a couple of 2x4's across the width of the shell to stabilize the width; now you have a frame that stabilizes the shell shape where the floor was. Then I ran 2x4's from the "floor frame" up the beam at each end of the beam; now the shell is stabilized top to bottom.

After forming the internal frame and lifting the shell off the trailer frame, I then sat the shell down on concrete blocks and strapped the internal frame to the ground. Out here in Arozona the wind can be fierce and can easily move an Airstream shell.

Feel free to email me if you want more detail.... morganobenn@gmail.com

[HiJoeSilver]

Gantry or a crane.
I tried taking mine off with jacks on each corner, it was a nightmare and disaster. Quickly wished I'd just built gantrys. Putting it back on I hired a crane. Still a little nerve racking.
Gantrys allow nice slow raise and lower of the shell and good controll.
Gantrys can be used later for getting roof access, putting up new AC, polishing, etc.
Make sure shell is well secured to ground once it's off.

[dbj216]

I have found several professional restorers giving excellent advice to us hobbiest for free. You will note in their profile they are "commercial members". But the folks seem very knowledgeable, and very helpful. Their business comes from the folks who don't want to lay under a trailer with mouse droppings, insulation and then POR 15 falling in their faces. Custom Airstream restorations are well into the five figures, but the customers get essentially a new Airstream built the way they want that looks like an old one. Some of these trailers are magnificent.

There are many Forum threads on axle assessments. I learned here on the Forums that the 4 rubber rods in the axles get hard with age. And they can loose shape. Old, hard axles have little suspension effect giving the trailer a jarring ride. I learned the design life of these axles is about 30 years, more if the trailer is used a lot, less if the trailer sits a lot. Your trailer is nearly 40 years old. So jack it up, take the wheels off, and look at the unloaded droop, or "starting angle" of the swing arm. Airstream used 22 degrees for a starting angle. When the weight of the trailer is on the wheels, the starting angle becomes more horizontal. Sometimes old worn out axles causes the trailer to be a "low rider", loosing ground clearance, as if you put a ton of weight in the trailer over the axles. Many Forums members can simply look how the trailer sits on level ground and give advice on the axle condition. Since you want an excellent condition trailer for living in and traveling with, then I recommend new axles just based on age. My axles had hard rubber even though the starting angle was about right. My new axles were about $700 each including shipping, and that included new brakes and bearings. They are not real difficult to change out.

Gantrys and two hoists with shell bracing is a very good way to lift the shell off the frame. Lift it up like lifting a paper bag off a something. The shell is flimsy without the subfloor and frame attached. Semi-monocoque construction; light but strong when all elements are working together.

You're going to build one sweet trailer. It will be just the way you want it. I hope someone told you how much it will cost. I've spent over $13000 in stuff on mine over the last two years, the axles and fridge being the most expensive purchase. So don't get too far down this slippery slope without knowing the cost of what you are about to do. Unlike advice on these Forums, it ain't free.

David

[HiJoeSilver]

Missed the axle bit, if they're remotely original replace them.
If the arm angle is zero or close to it or even negative, that's one starting point on replacing them. If you lift the trailer frame and the wheels don't move down, that's another, about the only way to see the effect of hardened rubber rods.
I highly recommend Colin Hyde as a source. He can get you exactly what you need, unbolt and un wire the old ones, new ones slide right into place. Search google, Colin Hyde airstream, and give him a call when you're ready. Since you're just starting if recommend waiting since they can be swapped any time and you'll have enough on your hands getting the shell off and back on and everything in between. Check axle threads and you'll see Colin has a great rep.

[perryg114]

My 81 axles are still good but they are sagging to some extent. I have not noticed any vibration or impact related damage inside the trailer. If you jack the trailer up and the wheels don't drop at least an inch then you have problems. I will replace mine at some point but it is way on down the list compared to getting all the major systems up and running and keeping the trailer leak free. I think many folks on here replace the floor and axles then they run out of steam and money and it ends up as an aborted mess on Craig's list.

Running E rated trailer tires at 80psi causes more damage than bad axles. I use soft cushy car tires inflated to 50 psi.

Perry

[CustomShop]

morganobenn - Sounds like gantries are the way to go. Thanks for the detailed description. I am getting old enough that I realize it's okay to spend an extra couple hundred bucks to do something right and minimize bullshit. Do people often go with two gantries, or is one sufficient? The shell is light from what I can tell.

dbj216 - You're so right man. I'm stoked to get her together. The goal is to do it all right this time around so I hopefully won't have to open her up for another 25-30 years at the least.

Regarding the carriage bolts that hold the shell down, do people use impact tools to get those off or just hammer em straight and use hand tools?

My axles sag several inches. I backed them onto improvised 2x12 'jacks' to get her up in the air for some belly pan and banana wrap work. The rear tires went on and the fronts just fell down about 3 inches. I'll check the angle of the dangle too.

Finally, I would like to ask about bracing the shell. Is that just intuitive? How is the lumber secured to the shell? Holes and zip ties??

[dbj216]

I see pictures where folks use two gantries. One lifting from the front 14" roof vent hole, and one from the rear vent hole. They usually use a 4x4 beam between and lifting from both the front and rear at the same time. Inch it up slowly, it usually is stuck somewhere (the infamous hidden rivets). You will need some bracing as the shell is flimsy like a paper bag without being attached to the floor and frame.

The bolts that hold the shell down and the sub floor to the frame are flat heads, I hear them called "elevator" bolts. Most folks simply grab the threaded part from the bottom with a vice grip and just wiggle until the bolt breaks. Usually the rusted bolts make fracturing them a "snap" (no pun intended.) The flat heads do not interfere with the floor covering you plan on putting in.

You need to have an accurate trace of your front and rear corner radii before you lift the shell. Some folks make a luan template. The old subfloor may be rotted away and inadequate for a template in itself.

It's a good thing your wheel dropped when you backed it up on the ramp. That means your rubber rods aren't hard like hockey pucks. Yes, check the angle of the dangle and see if it is about 22 degrees.

Make sure you have a plan (I'll bet you do). I found I had to be very careful in routing my drain plumbing to the holding tanks, as well as furnace ducting, as well as fresh water plumbing. Airstreams are tightly packed campers and every inch is dedicated to something. Layout your interior in detail so you know where electrical, plumbing, appliances, and cabinets will all go. One will affect the other.

David

[morganobenn]

I recommend two gantries. It will be easier to control the liftoff.

Also, as others have pointed out, the gantries are very useful for working on the trailer frame. I used them to hold the frame vertically to sandblast it prior to recoating it. Also handy for axle work -- flip the frame over and rest it on saw horses. Hoists good for removing/replacing axles.

On floor removal, I used a grinder to cut the bolts out on the floor side and then a punch to have them fall out the bottom.

On frame pattern, I retained the old floor as it was not too badly rotted. The curvature can be replicated from the old floor.

DO NOT use zip ties to attach the internal frame to the shell. They harden and break after a short while in the sun and weather. I used some of the rivet holes through which I passed screws. However I fashioned some wood blocks to use as "washers" to keep the screw heads from deforming the aluminum of the shell. I will try to describe this in words:
1. Attach some 2x4's along the bottom straight sections of the shell where the shell was attached to the trailer frame. This is where I used deck screws through the rivet holes.
2. Run some 2x4's across the bottom between the 2x4's that are attached to the sides of the shell. This will preserve the shell width where the the floor was installed.
3. Run some braces up from the side mounted 2x4's up to the beam along the roof. This forms a triangle in the cross-section of the shell to stiffen it top to bottom.
4. Run some braces in a triangle patter across the bottom where the floor was to give stiffness where the floor was installed.

[Belegedhel]

Um...again, have a look at the following link:

http://www.airforums.com/forums/f36/...on-115765.html

It shows how the two gantries are used to lift a shell, as well as for frame work.

In the spirit of offering "professional" advice, within the above linked thread (toward the end) is some discussion about bracing, from a forums member who actually gets paid to do rennovations. His take, my experience, and many others' is that bracing is not needed when lifting the shell from above. This is the beauty of using the gantries--yes you will spend some time and money building them, but you will save time and money by not fussing with interior bracing to jack against.