Community Forums

stripperguy · 09-27-2022, 02:15 PM

I recently acquired a 2010 Allegro RED 38QBA.
It needed some repairs after an electrical fire, I’ve already repaired all of that.
Now I notice that there is a pronounce sag in the rear end of the coach, nearly 2”.
I spoke with the guys at Tiffin, it is a known problem.
They would repair it if it was less than ten years old.
So I’m on my own.

Have any of you here had the sagging rear end repaired? If so, could anyone post some pics?
Has anyone repaired this themselves? I’d love to have more guidance than I got from the conversation with the Tiffin service guys.

Thanks in advance

accsys · 09-28-2022, 06:48 AM

We had our 2007 Phaeton rear sag repaired in April of 2018 at the Tiffin Service Center in the mechanical bay. It wasn't under warranty but they still repaired it for us. The cost was only $262 at that time. It required jacking the rear end up, removing the old broken braces and welding new ones in place - took about two hours total. They have done this many, many times and know what they are doing.

You might give the folks in the mechanical bay a call and see if they can work you in. That bay is one of the only areas you can get an appointment, at least it was then.

stripperguy · 09-28-2022, 07:14 AM

John (or Doris),
Thanks for the reply.
Tiifin service? I suppose that was down in Red Bay? That's not really an option for us, I wouldn't trust the coach on a 1,500 mile trip for structural repairs.
But the cost in 2018 dollars surely was reasonable, which leads me to believe that it's a relatively simple fix.
I would ask for pics of the patch, but I see you've divested...
Do you know if they welded in braces in one lengthwise location? Or did they add multiple braces along the length of the sag?

FWIW, I did talk to their service guys, but the description of a fix was rather cryptic.
They did say they no longer warranty repairs over 10 years of age, maybe changed since the new owners took over.

accsys · 09-29-2022, 06:13 AM

I would call Tiffin and ask who they would suggest fix it that is near your location. If on the east coast I know that many use Connecticut Cars, or something like that, for Tiffin repairs and have been happy with them. I believe there are one or two places on the west coast that Tiffin recommends as well.

I wouldn't be concerned about driving it with the rear sag. We put many thousand miles on our 2007 and didn't get it fixed until the rear sag had made securing the rear PS compartment doors a problem to latch. I believe they actually used multiple braces along the chassis but am not sure,

PKI · 09-29-2022, 10:44 AM

https://www.irv2.com/forums/f106/rec...es-585819.html

That was not much help .... tried to search, but came up basically empty. I know I have read about this problem. Suggest you check the Tiffin RV network site and see if they have any posts on the issue.

It was my understanding that Tiffin Service had some custom tooling that raises and holds the structure in the proper position so they can add the required bracing. Another service provider in the Red Bay Area may have the tooling or at least the expertise to do the repair with a minimum of learning.

stripperguy · 09-29-2022, 11:00 AM

John,
Since my last post I received a call from Tiffin's head of service.
He offered to repair the sag for a minimal fee, but our costs to travel there make the offer impractical (fuel, tolls, lodging, temporary transportation, etc).

While he gave me further descriptions of a fix, he doesn't have any formal guide to share. He did mention that they have a couple coaches coming in next week for a similar repair, and he'll take some photos as a guide. Also, he plans to send me a couple of necessary brackets.

Overall, it's more than I could have asked for...

I was actually under the coach when the Tiffin guy called, I had rigged up a 20 ton hydraulic jack along with a 10,000 lb load cell, to determine the loads required to eliminate the sag. As long as I have a ballpark value of the loads, I can adequately engineer and design any necessary bracketry. Surprisingly, half of the sag was removed with less than 1,500 applied load. (passenger side only)

As far as the repair in a shop near me, I prefer to do my own work.
I am a retired design engineer that still owns the R & D company that I co-founded.
In a former life, I was an apprenticeship served toolmaker, with certifications for MIG and TIG welding. I have a lifetime of experience repairing all manner of motor vehicles. I regularly resurrect insurance wrecks for fun and profit. This is my 3rd motorhome resurrection, I'll likely keep this one since it is in excellent condition with but 9,700 miles on it.

accsys · 09-29-2022, 11:45 AM

From what I understand, in order to repair it, you will need to devise a way to raise the house while keeping the chassis down. The mechanical bay did it over a pit and I believe they used chains wrapped around the rear axle to hold the the chassis down. One way to see if you have raised the house to the proper position is to look along the PS of the coach from the front so that you can view the trim above the PS compartments. When sagging you definitely see that trim take a downward angle just behind the rear wheels. When that trim stays straight that would be an indication you were near if not at the level needed. If you are welding on the coach I know there are some things that need to be done to protect the electrical system while welding but don't know what they are specifically.

I would still run to Red Bay the next time you are out touring and let them do it and know that it was done correctly and would last as long as you kept the coach. You would be spending much more on diesel than the repair but it could all be part of spring or summer vacation. The mechanical bay will most often accept an appointment for the repair unlike the rest of the service center.

stripperguy · 09-29-2022, 03:27 PM

The tiffin guys did say they chain down the frame and then use two porta powers to lift the coach. Along the way they may or may not need to cut any existing supports free.
I’ve already characterized the stiffness of the sag, chaining down the frame doesn’t seem to be necessary, gravity is pretty effective and reliable.
As I mentioned, 1,500 lifted half of the sag, the engine alone weighs 1,100 lbs, so there’s plenty of weight to work against.
I have previously used a chalk line to determine a straight line along the trim, it should be easy enough to know when everything is realigned.
As far as welding precautions, I just need to cut the power to the chassis and coach before welding to protect any electronics. It would be a bummer to fry my ECM!!
It looks like the most challenging part of the job is finding (or creating) enough room to work. Luckily, I’m a wiry guy, and I don’t take up too much space.

thegats1 · 10-05-2022, 06:14 AM

Quote:

Originally Posted by stripperguy

The tiffin guys did say they chain down the frame and then use two porta powers to lift the coach. Along the way they may or may not need to cut any existing supports free.
I’ve already characterized the stiffness of the sag, chaining down the frame doesn’t seem to be necessary, gravity is pretty effective and reliable.
As I mentioned, 1,500 lifted half of the sag, the engine alone weighs 1,100 lbs, so there’s plenty of weight to work against.
I have previously used a chalk line to determine a straight line along the trim, it should be easy enough to know when everything is realigned.
As far as welding precautions, I just need to cut the power to the chassis and coach before welding to protect any electronics. It would be a bummer to fry my ECM!!
It looks like the most challenging part of the job is finding (or creating) enough room to work. Luckily, I’m a wiry guy, and I don’t take up too much space.

If you have pics and also pics of the issue and method of repair and final repair, that would be really cool to see. I don't have the issue, but I love seeing things like this get solved.

Ohio44718 · 10-05-2022, 06:56 AM

If I remember correctly. There are a number of pictures someone took during their repair and posted it on the tiffinrvnetwork.com site. If I get a chance will poke around and see if I can find a link for you.

Update: here is the link: http://www.tiffinrvnetwork.com/forum...agging#p857729

This is the post with the picture: http://www.tiffinrvnetwork.com/forum...t=Weld#p790440

stripperguy · 10-05-2022, 06:19 PM

Mr Ohio,
Thanks for that!!
I am currently awaiting approval of my registration for that site, once I'm approved I'll be able to use that link and see the photos.

stripperguy · 10-13-2022, 05:08 PM

If any of you remember, my 2010 38QBA Allegro Red had a bad butt sag, apparently a known, common problem.
Given that the coach is now 12 years old, and it would cost me around $3,000 to travel back and forth to Red Bay, not to mention the cost of the repair itself, I chose to repair the sag myself.

Passenger side was sagged nearly 2-1/4", driver side about 1-3/4".
After looking at the OEM bracing, it was a wonder the back half didn't just fall off!

Here's one of the passenger side OEM braces. This one goes from the Freightliner frame up to a piece of very thin walled 1-1/2" square tube cantilevered off of the floor framing, roughly in the middle of the engine hatch.

Here's the same bracing, viewed from above. You can see a failed weld.

Now here's the rearmost bracing on the passenger side. It looks like some sort of Rube Goldberg design,

I used a couple of hydraulic jacks to prop up the sagging rear end, supporting it where the main wall framing passes by the storage compartments. I added some 1-1/2" 14 gage wall square tubing under the wall framing. I removed the spindly vertical support in the 1st two pics, and used more 1-1/2" square tubing.
I then added braces from the Freightliner frame to my added 1-1/2" tube.
Too hard to describe, better to just show a photo.

I next removed the rear most bracing (Rube Goldberg design) and replaced it with some 1" x 3" 14 gage wall rectangular tubing.
Even though the OEM bracing back here was adequate in strength, the multiple part, convoluted design negated any material strength.

Here's a photo of that rear most bracing that I installed.

Driver side was easier to repair, it needed only the removal of the OEM rear most bracing

Again, I added in my own bracing, some 2" x 1/4" angle. Here's a look at that.

In both rear most braces, I attached the supports directly from the Freightliner frame to the vertical wall framing, rather than several cantilevered arms. I also took advantage of a better orientation of the structural tubing. I won't bore you with the calculations and formulas, but trust me, it's a vast improvement over the OEM build.

And yes, I disconnected all battery power from the coach and the chassis before welding anything. And before you critique my welds, just know that all the pic show everything tacked in place only. After the pics, I went back around and finish welded all the joints.
After reconnecting the batteries, I verified that all systems still work properly. So I guess I got lucky!!

Finally, here's a couple photos of passenger and driver sides after all was said and done. I still have a compartment door that needs the hinge adjusted, but it's gonna last for quite a while as it sits now. I do have a tiny bit of sag remaining on the passenger side, roughly 1/8", but I'm not planning to address it any further. I'm comfortable knowing that my repair will not sag for the life of the coach.
Don't forget, the PS sag was 2-1/4", DS was 1-3/4".

thegats1 · 10-14-2022, 12:11 PM

That's impressive. Having the tools and know how saved you some money. Personally, since I have no welding knowledge, $3000 sounds like a fair amount for that amount of work. However, doing it yourself, you know exactly what was done. Nice job.

stripperguy · 10-14-2022, 06:41 PM

Quote:

Originally Posted by thegats1

That's impressive. Having the tools and know how saved you some money. Personally, since I have no welding knowledge, $3000 sounds like a fair amount for that amount of work. However, doing it yourself, you know exactly what was done. Nice job.

The $3,000 would be just my cost to get to Red Bay and back home!!
The Tiffin dudes estimated a typical sag repair might be between $400 and $600, not really too bad, but still a whole lot more than my $160 for steel tube, and my 1-1/2 days of futzing around.

Half of the reason why I post these repairs here, is to possibly help others that may have the same issues.

The other half of my reasons are to encourage others to take on a challenging effort, and maybe learn a bit in the process...learn about the specific job and even learn a bit about yourself.

Oh, and thanks for the accolades.