rear bath question - '70s and '80s

[farmerdave]

Do all rear bath models have problems with the frame or is it just the excella? Also is the excella or the sovereign the top of the line?

I have just started to consider going with a rear bath floor plan with the twin beds for my family. I would install bunks above the twins and use the pullout in front for wife and me. (4 kids) It seems like it would be a good functional layout for us. Any thoughts on what years to avoid and what problem areas to look for would be helpful. I have figured out from reading the forum that there is some problem with thermopane windows, but I don't know which years had them.

I also read about a frame strengthening kit, but I haven't figured out what it is or looks like to see if it has already been done. I am envisioning some kind of welded on steel that makes the frame rails deeper, in which case I could make it myself in my shop. Does it only reinforce under the bath area or is it the whole length of the trailer?
Thanks in advance,
Dave

[Inland RV Center, In]

Originally Posted by farmerdave

Do all rear bath models have problems with the frame or is it just the excella? Also is the excella or the sovereign the top of the line?

I have just started to consider going with a rear bath floor plan with the twin beds for my family. I would install bunks above the twins and use the pullout in front for wife and me. (4 kids) It seems like it would be a good functional layout for us. Any thoughts on what years to avoid and what problem areas to look for would be helpful. I have figured out from reading the forum that there is some problem with thermopane windows, but I don't know which years had them.

I also read about a frame strengthening kit, but I haven't figured out what it is or looks like to see if it has already been done. I am envisioning some kind of welded on steel that makes the frame rails deeper, in which case I could make it myself in my shop. Does it only reinforce under the bath area or is it the whole length of the trailer?
Thanks in advance,
Dave

The frame beef-up kit, does absolutely NOTHING for the rear end separation.

The separation, is caused by 2 reasons.

1. The shell to frame hold down at the rear, was marginal.

2. Lack of proper running gear balance.

The fix is not difficult, but does take a few hours.

Also, adding to the frame at the rear, will make the separation even worse, in time.

The strength is in the shell, NOT the frame.

Andy

[farmerdave]

That is not at all what I thought it was for. Where does the separation happen? I thought it meant that the frame was dropping out from under the shell (separating). What problem does the frame beef up kit address then? Does anyone have pictures of the two different problems and their solutions?

[Inland RV Center, In]

Originally Posted by farmerdave

That is not at all what I thought it was for. Where does the separation happen? I thought it meant that the frame was dropping out from under the shell (separating). What problem does the frame beef up kit address then? Does anyone have pictures of the two different problems and their solutions?

The separation happens when the frame at the rear, drops from the shell.

The frame beef up kit is wlded in place at the axles. It "supposedly" beefs up the frame !!!

Why needed?? No one knows.

The frame when made sometimes had the axle mounting plates improperly welded, by not using enough welding to hold the plate to the frame. That plate could buckle.

To avoid that issue, you can check to make sure the axle mounting plate is welded with minimum gaps between the welds, at the bottom of the frame.

If there are excessive gaps, simply fill in those gaps with welds.

Then, there is no need for the frame beef-up kit.

Again, the frame beef up kit has nothing to do with rear end separation.

There have been many posts about the rear end separation previously within this Forums.

Andy

[Minno]

Rear end separation happens when the shell is no longer connected to the frame at the back end of the trailer. The construction in the early 70's (not sure how long this lasted) is: the plywood sits on top of the frame. Then, at the rear, there's a plate that is angled and it goes underneath the c-channel and extends up inside the outer skin about 3 or 4 inches. The plywood is bolted to the frame. The c-channel and this plate are screwed and bolted to the plywood. Then the skin is riveted to the c-channel and the plate. The problem comes in when the plywood rots away due to water damage, or other physical damage causes it to break. Since the shell has no direct attachment to the frame other than the plywood, the frame and shell can become separated fairly easily. The fix that was applied to our 72 was to weld a steel u-channel between the main frame members directly underneath the plywood and c-channel. Then extra bolts are extended through the c-channel and plate, through the plywood and this u-channel, providing a much more solid connection between the shell and frame. Worked fairly well on our trailer, until the plywood rotted out. But even then, the bolts through the u-channel limited the movement between the shell and frame. The problem tends to be worse on the longer trailers. If you put a foot on the bumper and you can push the bumper down without moving the shell, there is rear end separation.

The frame reinforcing plates bolt (or weld) onto the frame directly over the axles. They are intended to solve a frame sag problem as I understand it. The way to know if your frame has sagged it to use a string line (a chalk line works) inside the trailer. If you do not have rear end separation, then when you run the string line front to back the entire length of the trailer supported on say a 3/4" board at each end and pull the line taut, if the line does not touch the floor in the area over the axles, then you do not need the reinforcing kit. You can also check with a level on the floor. If you level the front of the trailer, and then move the level behind the axle, if the level shows the floor is sloping down to the rear, and you do not have rear end separation, then you have frame sag. The frame would then need to be straightened and the reinforcing plates bolted on. At least, that's how Andy explained it to me a couple of years ago.

We had rear end separation, but not frame sag in our 72 Sovereign (31 ft). One problem with read end separation is that it can cause you to think you also have frame sag (like we thought). But, once we solved the rear end separation issue, we found out we did not have frame sag at all.

Hope this helps.

Chris

[Minno]

Originally Posted by Inland RV Center, In

To avoid that issue, you can check to make sure the axle mounting plate is welded with minimum gaps between the welds, at the bottom of the frame.

If there are excessive gaps, simply fill in those gaps with welds.

Forgot about checking the welds. But, it was 3 years ago when Andy went over it with me...

[dwightdi]

From my knowledge from my 77 31 footer: You can have at least two problems with the frame and separation. The most common is frame bending between or just after the rear wheels. This can most easily seen by looking from back to front down the wheel mounting plate. It should be straight. If it has a warp in it, the frame is bent and will need to be straighten before you do anything else. You could also use the string or level method mentioned above. After you get the frame back to being straight, then you should add the frame strengthening plates made by Airstream.

If there was a bend the frame, separation from the body is more likely to occur. Check for frame separation by jumping on the back bumper. If it is loose you need to fix it. The easiest way is the use the elephant ears fix that Airstream recommended. If you have the interior walls out anyway, you can bolt directly or use the u-bolts. You will also have to fix any rotten plywood for any of these fixes to work.

If there is a bulge when looking down the side of the trailer, you could have a bent frame and/or the outriggers are rotted out or bent. If the interior walls are pushing holes into the ceiling, you definitely have the outriggers collapsing. You need to drop the banana skins and weld in new outriggers.

[4RXLA]

The Excella was the top of the line up until the early 80's when the Limited was introduced.

[farmerdave]

Thanks for the responses.

So when did Airstream figure out that there was a problem and fix it? 80's 90's never?

Dave

[casa3805]

Originally Posted by farmerdave

Thanks for the responses.

So when did Airstream figure out that there was a problem and fix it? 80's 90's never?

Dave

Ours is an 84 Dave (twins in the middle and rear bath) and we have had no problems at all. I do keep reading about the separation and I am very wary, but I think something happened in the early to mid 80's that changed it all. I am sure a history buff can chime in about different ownerships for Airstream and changed designs..

[dwightdi]

I think 1984 was the year Airstream decided enough was enough and went to the 5 inch deep frame to solve the weak frame situation that lead to all the bent 4 inch frames. The problem of frame separation, due to poor connection between the frame and the body of the trailer in the rear was solved by increasing the quality and quantity of the fasteners. There still was the problem of leaks in the rear seal system which lead to plywood (or OSB) floor rot. This causes poor connection between the body and the frame also as the floor is sandwiched between them.

There is no such thing as a indestructible trailer. I have seen units as late as the 2000's that have had frames destroyed and rotten floors. Several recent International Presidents, who put on lots of rough miles, have had to have their units repaired with the elephant ears fix to reattach the frame to the body.

[HiHoAgRV]

Originally Posted by dwightdi

I think 1984 was the year Airstream decided enough was enough and went to the 5 inch deep frame to solve the weak frame situation that lead to all the bent 4 inch frames. The problem of frame separation, due to poor connection between the frame and the body of the trailer in the rear was solved by increasing the quality and quantity of the fasteners. There still was the problem of leaks in the rear seal system which lead to plywood (or OSB) floor rot. This causes poor connection between the body and the frame also as the floor is sandwiched between them.

There is no such thing as a indestructible trailer. I have seen units as late as the 2000's that have had frames destroyed and rotten floors. Several recent International Presidents, who put on lots of rough miles, have had to have their units repaired with the elephant ears fix to reattach the frame to the body.

A quick point - I had a '77 that had 5" frame rails so not ALL of the 70/80's were "frame issues"...

IMHO, the reason tail droop is so noticable in that era is two fold. Most units were rear bath which included a bunch of floor penetrations AND all of the leaky stuff was right at the back. This cause a better than even chance of the floor getting soaked and failing.

My '77 had been well cared for and had NO signs of floor rot in the back, thus no tail separation.

[Sneakinup]

My 77 31' Sovereign has a 5" frame as well. Oddly enough, the bulk of the "rear end" problems stem from water pouring in through the rear tail light assemblies. I would never have known this if I didn't remove the rear interior wall panels and stand inside during a torrential rain. This caused the bulk of the damage to the rear cross member and C channel. The back bumper compartment certainly contributed.

So, if you have water seeping in and can't figure out where it is coming from, check your tail lights!

[Minno]

Our '72 31' Sovereign also has a 5" frame.

[farmerdave]

So did frame thickness randomly switch between 4 and 5 inches thick, or was there some kind of order to the madness?

[4RXLA]

I'm adding to this existing thread instead of starting a new one. After a 3000 mile trip last year, I noticed that my 77 rear bath Excella 500 was starting to lose exterior rivets around the wheel well on the road side and a dimple that has been visible for years just aft of the wheel well starting to look bigger. A stress crack had also developed over the door about a year ago. 10 years ago over a dozen interior rivets had sheared off when my parents owned the trailer and were actively attending WBCCI rallies. The trailer sat dormant from 2002-20010.

The axles were definitely shot and I had them replaced first thing 2 years ago with a pair of 4500lb henschens when I took ownership of the trailer. The trailer weighs 7500lbs empty per CAT scale. Since the axle replacement I have not lost any interior rivets and I replaced all the broken ones. However, the door frame crack did appear shortly after the axle replacement and as I said earlier the dimple grew larger. Also, the rear bathroom, which has always had the feel of a downward slope seemed to have more of a slope than usual and the rear appeared to be sagging in phootos.

In preparation for my next 3000 mile trip at the end of May, I took the trailer in to have the frame inspected. The belly pan had never been removed before. The shop found good news and bad news. The good news is that the steel frame has absolutely no rust and the plywood floor and insulation are like new and very clean. All the outriggers are good and bolts are secure. The bad news is that the frame is cracked on the road side just above the rear axle and there is noticeable frame sag heading rearward, mainly on the road side. There are also a couple of sizeable dents in the bottom portion of the road side C channel...one is directly between the axles and may have been caused from improper jacking? The second one is about 6 feet farther back in the same area as the dimple. That could help explain the dimple? The crack extends accross the top of the C channel. The welder will straighten the frame and reinforce the C channel with additonal plating.

While I'm 99% sure the frame damage was mainly caused by driving on bad axles over many years, the shop said the 2 year old new axles are not bolted tight enough to the frame and are moving...Especially the rear axle where the frame crack and sag is. In the picture you can see evidence of the axle moving as the mounting hole is elongated. I've put about 7,000 miles on those axles in the past 2 years.

On the bright side I know my frame is rust free and once welded will be solid for years to come. Having seen so many pictures of rusted out frames and outriggers and moisture soaked insulation on these boards, I was expecting much worse than what I found. We originally were going to drop the rear holding tanks to see if there was any rust or breakage but given the rust free condition of the rest of the frame, the shop suggested I avoid the cost of all that labor as there definitely is no rear frame separation, just frame sag. I was surprised to see the frame painted black from the factory. I had assumed the frames were unpainted or painted gray based on pictures of 70's trailers on the forums.

Everything should be fixed and ready to roll on the 29th for Yellowstone.