Rear-end Sag, Educate me please!

[lebolewis]

I seem not to be very good at finding useful information on a particular subject, using the "search" function on this site....is it just me...or is it the system? I always get a return of hundreds of threads that take many hours to read and provide very little useful information! Oh well.

I am looking at a 79 Excella 500 as a purchase candidate. I was talking to the owner on the phone and I ask if it had any "rear-end sag". He said he didn't know, but then he vaguely described some loose screws in the rear, above the bumper, that needed some repair. So, my questions are, (1)What is "rear-end sag". (2)How do you spot it? (3)And, how do you fix it?

Thank for the help. Bill

[Anon]

Originally Posted by lebolewis

(1)What is "rear-end sag". (2)How do you spot it? (3)And, how do you fix it?

Thank for the help. Bill

1. It is a separation of the frame from behind the back axle on a tandem axle Airstream. It sort of looks like the frame is starting to "dangle".

2. Oh, you will know it. My Dad's '73 31-footer had it. The back of the trailer will develop a gap between the bumper storage compartment and the super-structure of the trailer itself. It will also start to "pull" in the belly pan below.

3. The only way I have ever seen it fixed is when my brother-in-law had it repaired at Airstream in Jackson Center. It was not cheap either. They also only warranty the repair for a short amount of time. He had it repaired about 6 years ago and it was starting again last year. He took it back down there and they fixed it again. I am not sure how much it cost but it is a deal-breaker when the price of a trailer seems high.

[lebolewis]

Originally Posted by pattersontoo

1. It is a separation of the frame from behind the back axle on a tandem axle Airstream. It sort of looks like the frame is starting to "dangle".

Thanks Lou, .....Another question for you or somebody....since all Airstreams do not have this problem, why only some?.....what are the forces at work that cause the "sag"? Why would the trailer frame drop down below the trailer body? Did I understand that part correctly? Bill

[AYRSTRM2]

Bill,

if you have a strong constitution and aren't easily frightened, then all is explained in this thread.

Sort of.

Now, keep in mind that you are talking about a '79 and that sort of is out of the range, but it still can happen. Here' how you spot it: Put your foot on the rear bumper. Look very closely where the shell meets the bumper. Push down with your foot. If the bumper moves apart from the shell then you have rear end separation. Which is not the end of the world. I know. There are several fixes: Cut elephant ears, ear shape patched from your exterior skin where the shell can be reattached to the frame and then the holes are patched over with more aluminum. Not pretty looking. Or they can remove all of your bathroom, remove the lower wall, tear our the rear floor, replace with new floor, reattach the shel and put everything back.

Your description of what this guy says does not in any way indicate that this coach has that problem. Vague loose screws just sounds weird since an AS has very few if any exterior screws, unless they hold on the license plate or tail lights.

Hope this helps, and good luck!

[lebolewis]

Originally Posted by AYRSTRM2

Bill,

if you have a strong constitution and aren't easily frightened, then all is explained in this thread.

Sort of.

Now, keep in mind that you are talking about a '79 and that sort of is out of the range, but it still can happen. Here' how you spot it: Put your foot on the rear bumper. Look very closely where the shell meets the bumper. Push down with your foot. If the bumper moves apart from the shell then you have rear end separation. Which is not the end of the world. I know. There are several fixes: Cut elephant ears, ear shape patched from your exterior skin where the shell can be reattached to the frame and then the holes are patched over with more aluminum. Not pretty looking. Or they can remove all of your bathroom, remove the lower wall, tear our the rear floor, replace with new floor, reattach the shel and put everything back.

Your description of what this guy says does not in any way indicate that this coach has that problem. Vague loose screws just sounds weird since an AS has very few if any exterior screws, unless they hold on the license plate or tail lights.

Hope this helps, and good luck!

Thanks Ayrstrm2, I read the WHOLE thing!! I feel like I am now an expert on the subject!!!.....well, not exactly. But, I now know what to look for! And....I know it can cost up to $3000.00 to get a fix at an AS repair shop....and maybe a loooong tow to get you to a good shop that knows how to do the job right. There seems to be lots of opinion and confusion remaining as to EXACTLY what causes it. My guess is that it is a combination of factors, all of them are mentioned in the thread. That's very valuable info when you are looking at used AS's. In spite of some "testy" comments by a few folks, this Forum continues to be a very valuable asset to AS owners. Bill

[Alumaholic]

Fast easy way to check is to stand on rear bumper and watch seam beneath belly band as you bounce up and down gently. Check both sides.

[Happycampers]

Bill, It happens mostly on longer trailers with rear baths, trailers 25' and 26' and below or long trailers with center baths don't usually have this problem. The cause is usually because of the weight of the water in the holding tanks. Marvin

[Alumaholic]

Originally Posted by Happycampers

Bill, It happens mostly on longer trailers with rear baths, trailers 25' and 26' and below or long trailers with center baths don't usually have this problem. The cause is usually because of the weight of the water in the holding tanks. Marvin

Bill,
The foregoing is a common misconception, or at least a point of common disagreement. I'm not sure who is right and who is wrong. Andy of Inland RV reports that frame separation is caused less by the weight of water in the holding takes and more by lack of proper wheel balancing. I suspect that it's probably a combination of factors.

My Airstream inspections have found a 25', 27' (rear bath), and 31' (center bath) with frame separation. Yet, I have found 30 year old 31' rear bath Sovereigns without it. So, my take is this. Since there is disagreement about the cause, just assume that all old Airstreams regardless of lenght or floor plan may have it; and make it a part of your inspection checklist.

By the way frame separation and tail droop are two different maladies, but that's another thread.

[stagecoachbill]

Before you tackle this problem ask yourself this question?
Am I doing a 5, 10 or 40 year fix on this problem? The price goes up with length of time? I fixed the tail sag on my 69 31' Sovereign this way after getting some advice from a professional restorer. The problem was: the rear bunper was sagging below the aluminum frame far enough so thet I could see all of the 3/4 inch plywood in the gap.
Solution: jack up the rear bumper with stands to the poiint that you are almost lifting the tires off the ground. (pur stabilizers at front corners of frame) I left it on these stands over the winter to get the rear bumper as high as I could, Got back almost 1/2". Then using 2" aluminum angle I rivited it to the aluminum frame and the bumper. The 2" alumionum L allowed me to place the upper rivets high enough to catch the U-channel of the frame, but i had to cut off some of the lower part of the L to make it fit on the bumper.( make some cuts in bottom of L to allow it to bend around side curve.) Using oversize rivets it worked out very well. No problems since I fixed it last year. Dont forget to use spray foam or a lot of caulk before you rivet it in place.

[Inland RV Center, In]

Rear end separation, can be caused by excessive weight at the bumper, and/or by lack of proper running gear balance, or some of both.

The longer the trailer, the more likely it could happen. But any length Airstream trailer, can have the separation, even a 17 footer.

When Airstream swithched the rear floor channel to a new design, the problem did not stop, but did tremendously reduce. That floor channel slipped over the edge of the plywood instead of just sittling on top of it.

There are temporary fixes, and there are permanent fixes.

The following is the correct permanent fix.

1. Remove the raer rub rail molding. Remove the two rear quarter panels. Cut them at the lower belt line molding.
2. Fold the rear plate upwards from the bottom.
3. You will typically find that the floor channel is in pieces.
4. Reweld the floor channel.
5. Replace any plywood thats necessary.
6. Remove the two rear banana wraps.
7. Weld a small 2 x 2 x 1/4 inch steel plate, "outward" of the frame, so that the banana wrap will hide it when reinstalled.
8. Replace the rear steel plate hold down if necessary.
9. Jack up the rear of the frame to place it back into it's original position.
10. Refasten or add additional 3/16 pop rivets to hold the "inside" quarter panels.
11. Fabricate at least 4 steel plates that will fit inside the floor channel.
12. Place one plate over the frame and the other over the added piece of angle that you welded outside of the frame.
13. Reinstall the floor channel.
14. Use 1/4 or 3/8 inch "plated" bolts with "large" flat washers, and lockwashers, every 3 to 4 inches as well as at least two bolts through each metal plate.
15. Replace the insulation if necessary.
16. Add a splicer plate to the inside part of the quarter panel that you "dad not" remove.
17. Reinstall the quarter panels, using 3/16 rivets at the belt line and at the floor line. Make sure you injected Vulkem sealer before you start to rivet.
18. Install olympic rivets to finish the job.
19. Reinstall the rub rail molding.
20. Clean up any excess vulkem.
21. Remove the jacks.
22. Go in the house and get a beer. Go back out to the trailer, and observe the beautiful job you did. After all, we know your Grandmother was supervising, so the job had to be far better than the original construction.

Those owners or or owners that allowed a dealer to short change the repair by using the "elephant ear" method, will pay dearly for it, in time.

Unless a person tows the trailer many miles over railroad tracks, you will "never" have the problem again.

However, adding weight to the back of the trailer, is always a no no.

Towing without proper running gear balance is a no no, as well, but not nearly as bad, unless you use square tires.

Keep in mind, anything can be destroyed, if we shake it enough, or subject it to enough vibration.

Those that are old enough, I am sure remember the cause of the Lockeed Electra wings falling off.

I forgot who wrote, "Why is it we can find enough time to do a job over again, because we didn't take enough time to do it correctly, the first time".

Or, when it fails again, sell it on e-bay.

Andy

[lebolewis]

Wow! Thanks, Andy.

This is not a simple problem to fix. This looks well beyond anything that I would ever attempt to tackle. I will do my very best to avoid buying a used AS that has any symptions of "REAR-END SEPARATION". And......if I muck it up, and it develops the problem, I will then seek out a competent repair shop to fix it.

Armed with all this good info, I will be out there, stalking them thar used Airstreams..... and the FIRST thing I will check for is, "guess what"?!! Bill

[Inland RV Center, In]

Originally Posted by lebolewis

Wow! Thanks, Andy.

This is not a simple problem to fix. This looks well beyond anything that I would ever attempt to tackle. I will do my very best to avoid buying a used AS that has any symptions of "REAR-END SEPARATION". And......if I muck it up, and it develops the problem, I will then seek out a competent repair shop to fix it.

Armed with all this good info, I will be out there, stalking them thar used Airstreams..... and the FIRST thing I will check for is, "guess what"?!! Bill

Bill.

The second thing that you "MUST" look at is the axles.

Are they OK?

Are they correct for the trailer?

Are they someones "home brew"?

Andy

[lebolewis]

Originally Posted by Inland RV Center, In

Bill.

The second thing that you "MUST" look at is the axles.

Are they OK?

Are they correct for the trailer?

Are they someones "home brew"?

Andy

OK, makes sense. So, help me out here. Can I stand 5 feet away, or closer, looking at the wheel-wells and the wheels, and tell if the axles are good? If not, how do I make a good (simple) decision about them? Bill

[Inland RV Center, In]

Originally Posted by lebolewis

OK, makes sense. So, help me out here. Can I stand 5 feet away, or closer, looking at the wheel-wells and the wheels, and tell if the axles are good? If not, how do I make a good (simple) decision about them? Bill

Bill.

Stand 15 to 20 feet away and stoop down so that your eyes are even with the wheel well.

You should be able to see some of the tire, "above" the top of the wheel, perhaps as much as 1 to 3 inches, depending on the model.

You can also read an article about the Duro-torque axle and how to check it by going to our web site, inlandrv.com Click on articles, click on the Dura-torque axle article.

Andy

[JHD]

Would a 1990 34' Excella be prone to this problem?

The one I just purchased doesn't seem to have it based on the posts on how to detect it, but I notice that the rear bedroom door is easier to open with the stabilizers down that when they are up.

I found nothing in my very well written owners manual saying anything about not opening the rear bedroom door with the jacks up.

FWIW, I love the new airstream. Worlds above my Streamline that I had. The wife and I are looking forward to many happy trips with our new baby.

JHD

[Inland RV Center, In]

Originally Posted by JHD

Would a 1990 34' Excella be prone to this problem?

The one I just purchased doesn't seem to have it based on the posts on how to detect it, but I notice that the rear bedroom door is easier to open with the stabilizers down that when they are up.

I found nothing in my very well written owners manual saying anything about not opening the rear bedroom door with the jacks up.

FWIW, I love the new airstream. Worlds above my Streamline that I had. The wife and I are looking forward to many happy trips with our new baby.

JHD

It could, if it was parked for an extended period of time.

However, the rear door problem is another issue.

That door can be realigned to solve the problem.

Andy

[JHD]

Originally Posted by Inland RV Center, In

It could, if it was parked for an extended period of time.

However, the rear door problem is another issue.

That door can be realigned to solve the problem.

Andy

Andy,

Thanks for the reply, the trailer was used every year up until last year, when the previous owner passed away. It was winterized and stored a covered RV lot in the winter months, and out on the road in the spring till early fall typically according to the owner's wife.

My question then becomes this, and not to digress this thread too much. Should the trailer be put up for the winter with the jacks down typically?

Based on your reply, It would appear that they should be.

Re-adjusting the door hadn't occurred to me, thanks for the suggestion. I am a decent mechanic.. are there any good articles on adjustding the door I should look at here?

I adjusted the door of my Streamline, it was pretty straight forward.

Thanks again,

John