Hold-down stirrup repair

I recently purchased a 98 3326 and have been getting everything ready for a summer vacation. After reading through your post concerning stirrup repair I recognize that I have the same problem on the side opposite the door where the aluminum tube is pulled down about 1/4 inch. I have a couple of questions about your most recent repair.

It sounds as though you just put silicone sealant and rivets on the outside layer of aluminum. Is that correct? Would it be better if the same was done on the inside or is it just too difficult to get to? It looks like I'm going to have to attempt this repair in the near future. Also where did you purchase the "Cherry Q rivets" that you used? Is that something you can pick up at Lowes or Home Depot.

Thanks
Dave

dlkcub, these "Q-type rivets" are special pop rivets and I doubt that you will find them at Home Depot, Lowes or any of your local general hardware stores. I believe that I purchased the ones that I used from McMaster-Carr - memory doesn't always serve me well since I purchased them a few years ago. Go to McMaster-Carr's web site and type "Q-type rivet" or "q rivet" in the search box. You will be presented with a page of several types of Q-rivets. I've been using the 3/16" dia. steel rivet with steel mandrel but the 1/8" dia. size should be easier to pop - and it has more than adequate strength. The stainless steel and monel Q-rivets also are suitable and will provide more corrosion resistance, but, are more expensive.

Yes, I applied silicone sealant and Q-rivets only between the outer aluminum skin and the existing 1" square aluminum tube. That was because, as I mentioned in my previous message, I consider this a "temporary repair." There's ready access to the outside lower part of the TM's shell without any major disassembly of the shell. I consider it a major repair job (for this senior citizen, anyway) to disconnect the front pair of my rear shell's lifting arms and tilt the shell backwards in order to gain access to the inside lower part of the shell. Then, in order to apply silicone sealant and pop rivets from the inside, one first has to remove the longitudinal bag seals. The seals are fastened to the inside of the walls with flat-head, square drive screws. If I were to take the time to do all of this, I would also replace the existing 1" square tube (0.035" thick wall) with heavy-duty, 1" square tube with a 0.125" thick wall. In addition, while I had the seals off, I would take the time to rebuild them with new foam and new fabric. If my temporary repairs fail, I'll have to do this extensive repair I just mentioned.

The holddowns on a TM's front shell are more highly stressed than those on the rear shell. That is because the front shell overlaps the rear one and helps to hold it down. The rear shell's 1" tube was pulled down because my front shell's holddowns failed first. Since I replaced the original 1" square tube on my front shell with a heavy walled tube and drove pop rivets into it through both the inside and outside aluminum panels, I do not expect either stirrups or tube to pull out from the bottom of its wall. My rationale is that the temporary repairs on the bottom edge of my rear shell should hold because the front shell's holddowns now are very strong. Rereading the previous descriptions of my front shell's repair may help you to visualize what I did.

Let me tell you that you may be able to pop Q-type rivets with an ordinary, manual pop riveter, but, it will be difficult. These rivets normally are popped with a pneumatic riveter because of the great amount of force that must be applied to break off the mandrel. Not wishing to spend $300 on the purchase of a pneumatic pop riveter, however, I made my manual pop riveter work. All it took was applying a parallel jaw woodworking clamp to the pop riveter's handles to make the final squeeze needed to break the mandrels.

Thanks Larry, I was able to find 1/8 stainless pop rivits at Home Depot I may give them a try. I plan on heading out next week on a two week vacation so I don't have time to do the major repair, even if I were able to, and hope to get by with your "temporaty repair". I have ordered new latches from TM but have not received them yet as the old ones are badly worn and weak. I recall reading about using a hold down strap. That should relieve some of the stress on the holddown latches and the shell until I can repair/replace them.

Thanks for your help

Dave

Larry,

Thanks for the help. Two night before I left on vacation I used your 'quick fix method". I found 1/8" stainless pop rivets at Home Depot (yes they were a bit pricey but time was of the essence). My new latches arrived the next day so that night I installed them and moved the stirrups by removing one screw and turning them around. In the last two weeks I’ve traveled over 4000 miles sometimes over some pretty rough roads and both the repair and the new latches held.

Thanks again.

Dave

Glad to be of help with advice, dlkcub. I hope that your temporary repair will hold for a long time. If the lower aluminum tube you repaired was that in the upper shell, though, you eventually may have to replace the stock tube with a heavy-wall one. That's because the holddowns on the upper shell not only have to hold the upper shell down but also assist in holding down the lower shell.

It was in the upper shell on the road side. I figure that somewhere down the road I'll have to make a more permanent repair but for now everything seems to be holding. I've got a few other repairs/improvements to make now. Thanks again for the help.

Dave

Personally, I am not very pleased that a trailer that has been in manufacture since the early '80s is still having this problem with the stirrups pulling screws out. It grieves me to see the screws move as normal setup loads are placed on them. It is easy to see that they will pull out, strip, deform the sheeting, and fail. Now this post is listing the folk who right now have problems with these pulled out and needing repair. The photos show how the operational stresses exceed the limits of the design. Man this is great stuff for a Mechanical Engineer to dig into.

The framing used to be wood. That changed mid to late '90s. The replacement aluminum is where the weakness is predominantely.

On my TM, I just beefed up the metal at the door where the clip pulled the screws out of the square tube. Fortunately, that was easy to get to. I also see the latch on top of the camper moving when it is closed or opened. I expect to see a big hunk of aluminum pull off there or at least the screws to pull out.

I sure hope Trailmanor takes a proactive stance in this and changes their design. It is long past due. Is there a way we can impress upon them the importance of this to their public image? What would it add to the trailer to increase the thickness of the square frame tubing around the edges? Maybe 10 pounds? Maybe $100? Unfortunately, the cost and inconvenience of repair far exceeds those numbers.

Bob

Bob, I agree with you that the TrailManor designs have had several weaknesses and shortcomings. The basic folding aspect of the design itself, though, is outstanding. This allows an owner to possess a trailer that's roomy when opened up and compact when folded down. But, you know this and how well a TM behaves when being towed. I currently own a box trailer, used to own a 16' conventional travel trailer and have rented many U-Haul trailers. They all had a tendency to sway, some more than others. I lost a wheel while towing a U-Haul trailer and another while towing my own box trailer. I attributed both to swaying. We haven't noticed the least bit of swaying while towing our 3124KS over 10,000 miles. Though I've not visited the TM Factory, I believe that it is a relatively small facility. "Small" also in that they may not have a large design and engineering staff. Those of us who are engineers may wonder why they chose to fasten each of the holddown stirrups with 2 sheet metal screws driven into the flimsy 0.035" thick wall of the 1" square tubes. This choice may have been a compromise between attachment strength and maintaining lightness in design - even though you and I would agree that they made a poor choice. Were this a GM or Ford design, their engineers would have mounted strain gauges at the stirrup mounting points to determine the forces being exerted there and then designed a sufficiently strong attachment method.

Those of us who have owned TMs for a few years have seen that the Factory does respond to customer feedback and criticism by eventually improving the weak design aspects of the trailers. We like to think that many of these improvements resulted from this web site's feedback to the Factory. Considering whether or not to purchase a TM is similar, in a way, to the thought process that goes through our minds before purchasing a computer. We can wait 5 to 10 years for a much improved TM or purchase one now and get to enjoy it - even though we're aware of its design weaknesses.

Larry,

I hear you. But how does one make product improvements? How does one entice the public to continue to return?

How does one make a Toyota? I drive one. It has a turn signal blinker that needs replaced. Has needed it since 1998. I will get it replaced when it needs to go to the dealer for another reason. Meantime, it has gotten 67,000 miles on it. Maybe someday, it will need to go back to the dealer. How did this car get to be so reliable? Believe me, when they see a defect at that factory, they correct it. Can we yankees learn from them? Actually, we taught them about quality. Unfortunately, at the time, yankee factories didn't want to hear about quality. Not until they saw the flood of imports, that is.

Camper manufacturing isn't rocket science, so you don't have to worry if one breaks in the field. Therefore you can resolve this without strain gauges. Gauges would provide the basis of an optimal design improvement.

But I can see the metal give when setting my TM up. Metal can't be forced to yield like that and pass the test of time.

Do they see a continual run of certain replacement parts from the warehouse? Do they see these break when setting new ones up? These are clues, my friend.

This weakness seems to me to be easy to spot, easy to improve and probably not too costly to eliminate.

Bob

Bob, it's good to have the web site back online, isn't it?

Toyota dwarfs TrailManor in size and therefore has a much larger and refined quality control program than TrailManor. The TrailManor's QC department may consist of 1 person, or, perhaps two at the most. TrailManor's output may be just a handful of trailers a day while Toyota's numbers in the thousands. With thousands being produced every day Toyota is more likely to find out (or be notified) about defects in their vehicles within a short period of time. Discovery of a defect in TrailManor's vehicles may take a few years - especially since none are likely to be on the road every day.

Every commercial product is a compromise between a quest to achieve a high-quality product and a need to get it into production to make some money. You know as I do that at some point the engineer has to be kicked out of the loop in order to begin manufacturing the product. TrailManor just may have kicked the engineer out too soon with respect to some aspects of their design. I believe, though, that they are striving constantly to improve the design of their trailers. We can see the improvements trickle into the new models year by year.

If you can see the stirrups, attachment screws or the underlying metal tubes moving when you set up your TM, that's a sign that the need for a repair may be impending. If you plan to keep your TM for several more years, it will be worth your while to insert heavy-walled tubes in the lower edges of the shells and rivet them in from both sides of the walls. It took quite a bit of work to accomplish that for my upper shell (tubes haven't yet been changed in my lower shell) but I now am confident that their stirrups will never tear out.