Hold-down stirrup repair

[Bill]

On our last trip, the stirrup half of the door-side hold-down latch ripped out of the front shell of our TM. This seems to be fairly common - there have been several threads discussing it. It turns out that the stirrup is attached to the body with two big sheet metal screws - but the body at this point is just a piece of 1-inch x 1-inch square aluminum tubing, and the sheet metal screws don't get enough of a grip in the thin tube wall. The factory apparently has a fix, but the fix is simply the addition of more sheet metal screws, and a couple members have reported that the fix rips out, too.

A real fix would involve thicker material, machine screws rather than sheet metal screws, and some way to spread the stress along some of the length of the tube, rather than concentrating it at the position of the two sheet metal screws. Following that thought, I implemented a more permanent fix today (I hope!).

First, remove the trim strip along the bottom of the wall - it is held in place with half a dozen small sheet metal screws, and the stirrup mounting bolts went through it. If the ripout was a doozy, like mine, this strip is all twisted and bent, and you'll need to straighten it. You can see in the photo that it is still pretty wavy in mine.

Now clean out the holes in the trim strip, and in the aluminum tube, where the original screws ripped out. These holes are an inch apart. Drilling them out to 5/16-inch is fine - we have no further use for them.

Next, get a piece of steel strip 3/4-inch wide, 1/4-inch thick, and 8 - 12 inches long. Home Depot, etc, has it. In the middle of the strip, drill two holes an inch apart, and tap them with 1/4-20 threads.

Now, get access to the end of the aluminum tube. To do this, you need to open the trailer, and remove the upper half of the door. If you don't already have a square-drive screwdriver, this is your excuse to get one. With the door off, you almost have access to the open end of the tube. You will need to cut out a small amount of aluminum trim - this cut will be covered when you reinstall the door.

Slide the steel strip into the open end of the tube, and push it along until the threaded holes in the strip line up with the original screw holes (now cleaned out). Reinstall the stirrup using 1/4-20 x 1 inch hex bolts with split lockwashers.

Hope the photo helps make sense of this. I took it just before re-assembling the door. The arrow points to the stirrup that ripped out (now reinstalled). The cutout opening for access into the aluminum tube is circled.

Thanks to Windbreaker for good offline discussion of this fix.

Bill

Bill,
Your method of repair (or was it Windbreaker's method?) should work - at least for the time being. May I recommend that you also fasten the 3/4" x 12" long steel bar to the inside of the 1" x 1" aluminum tube with a countersunk machine screw or pop rivet on each end. This will prevent the bar from moving if you ever have to remove both 1/4-20 hex head bolts. If they both fell out during a bumpy trip, for example, the steel bar would slide around and you'd have a devil of a time lining up its threaded holes with the holes in the bottom of the 1" x 1" aluminum tube again.

I still have not taken the time to complete the repair of the stirrups on the upper shell of my 3124KS. They came loose during our last trip of 2002 in September. Unfortunately, during our 7,000+ mile trip the holddowns were subjected to so much stress that the 1" x 1" tubes also were pulled down from the bottom of the shell. The damage was worst on the door side. Its stirrup was pulled completely off and the tube to which it was attached was pulled down about 1/2". You may be aware that the aluminum tubes are fastened to the bottom of the walls with adhesive supplemented by screws that are driven through the wood molding on the insides of the walls. In my TM this bond was not strong enough to hold the tubes in place.

My repair will require more work than yours. I purchased a 6' long aluminum tube, 1" square with 1/8" thick walls and cut it into two lengths, one for each side. I slipped a 6" length of 3/4" square, solid aluminum bar into each length of tube and pushed each piece along until it was centered on the spot where the stirrup would be fastened. I then spot welded the bar and tube together (with a rosette weld). What's left for me to do is first to jack up the front shell, and remove the old rear portions of 1" x 1" x 1/16" thick aluminum tubing. Then I will have to cement in the new lengths of square tubing - the Factory recommends the use of Dow Corning Silastic or its equivalent. Finally I'll have to reattach the screws on the inside wall (through the wood molding) and add additional screws or pop rivets through the outside wall. Since I will be attaching the stirrups with 1/4-20 hex head bolts into threaded holes, it will be just as if the stirrups were bolted to solid 1" square aluminum bars. I will probably attach the outer aluminum panels to the bars with 3/16" steel Cherry Q pop rivets (these have solid shanks, not hollow ones like the ordinary hardware store variety). The new tubes with 1/8" thick walls should provide ample strength to hold the pop rivets. Bonding the aluminum tube to the bottom of the walls with Silastic, screws on the inside and solid pop rivets on the outside should make it strong enough so that it will never come off again.

Since I've taken care of most of my most urgent chores and the weather looks as if it will remain dry, I may finish the repair job next week. I'll have to phone Donny Pilkey for advice on how to lift up the upper shell or review HappyTrails' site again to see how he did it.  

I understand what you are doing and it is most likely what should have been done in the first place but most of us, myself included, don't have the skills or tools to do what you are planning.

Do you guys carry backup tie downs of any type should this happen far from home? Would a rope pulled snug all the way around the trailer hold the thing down? :-/

Windbreaker,
Yes, on our trip from California to the East Coast last summer, I rigged up a rope tiedown after it was apparent that our upper shell's latches had failed. The tiedown consisted of some 1/4" dia. nylon/polyester rope and 2 small racheting pulleys that I purchased at a Lowes store in Georgia. The 2 small black-colored racheting pulleys came equipped with short lengths of soft, 1/4" polyester rope with steel hooks on their ends. To hold down the upper shell with this rig, we looped a long piece of rope (about 20' long), with a pulley tied to each end, over the top and down the sides of the shell (close to the open end, near mid-trailer). A shorter piece of rope with hooks tied to each end, about 7' long, was manuevered underneath the trailer. We connected the hook on a pulley to the hook on the lower rope on one side, then did the same thing on the other side. This created a loose loop, with a racheting pulley on each side near the street level. We then could proceed to rachet the upper loop down tight by tightening gradually one side then the other. It worked well enough to allow us to finish our trip without stopping for extensive repairs. We were able to pull the open end of the shell down so that there was only about a half inch gap between it and the top of the lower shell. You may need to put cardboard pads underneath the pulleys and rope to protect the TM's exterior finish. Even after repairing my latches, I intend to keep the pulleys and rope stored in my TM - just in case!

The kind of a repair job that I intend to complete on the latches is not difficult, just a little involved. Other than the heliarc welder I've used, the only other tools required will be hand tools available at hardware stores or tool supply stores. Even welding is not necessary as the 6" long square piece of aluminum could be fastened to the inside of the 1" square x 1/8" wall aluminum tube with sheet metal screws or machine screws (these require drilling and tapping) driven through the top of the aluminum tube. Look at the extensive repairs that Happytrails did on his 1980s vintage TM. They were an inspiration to me to tackle repair jobs like this on my own TM.

[Civil_War_Buff]

Larry and Bill have inspired me to want to retofit mine before my East Coast trip, but without going out and opening up the trailer, I was noticing the notch in the picture that Bill posted. It looks like the wall edge where the stock was inserted is screwed into the edge, so couldn't it be removed to facilitate the retrofit? or is there aluminum tubing behind it that would not allow the fix to be done without the channeling?

I would not weld mine either, but I will use a little caulk to hold the reinforcing bar in place, and I will tap the end closest the door so that I could insert a bolt and pull the bar out if I ever felt I wanted or needed to.

Larry

[Bill]

CWB -

Yes, by pulling out some more screws, you could remove another layer - the door frame - and get access to the end of the tube without cutting anything away. I guess I was just tired, and tired of the job. Since the door half of the piano hinge covers the cutout when the door is reinstalled, I figured what the hell, and just went ahead. But you are right, it would be more professional to do it right.

Bill

Yes, as a double precaution, I use a 2-inch wide webbing racheting type strap. I think I bought the 25' one, and had to cut it a bit short so as not to have a lot of extra webbing flapping about. I did take note that it was cheaper at Lowes than at Wallmart. The metal hooks on the ends fit just perfect over the travel arms, and as it's webbing, and not a rope, there's no worries of it denting the roof corners if I crank down on it.


[glow=red,2,300]Happytrails.........[/glow]

Bill, just posted a fix for the stirrup repair under the JB weld post. It also addresses the issue of spreading out the stress point as well............Lemmie know what you think......


[glow=red,2,300]Happytrails........[/glow]

[Civil_War_Buff]

Bill,

I picked up the bar stock yesterday, and I am going to affect the retrofit this week. I do have a couple questions, if I use a piece of stock that is longer than 4 inches there are other screws (sheetmetal) that are put through the bottom, between the door and the stirrup. Did you drill clearance holes for these? Did you just let the bar deflect when the screws are inserted?

Also, I noticed that there is a bead of caulk that runs down the door at the point where the hinge attaches to the jamb...what type of caulk do you use? I assume it is just white silicone caulk, but it might be marine grade (which I think I will use), but was wondering what the factory uses, assuming you know. :

I hope that I am making sense here.

[Bill]

CWB -

In my case, at least, there were no troublesome screws coming up through the bottom of the square aluminum tube. As I recall, there was one long drywall screw right at the opening of the tube, but I just backed it out and replaced it when the job was done. BTW, I used a piece of stock that was 8 - 12 inches long, if I recall correctly. At that length, it did not interfere with the screws that hold the trim strip on. A couple of these trim screws are, in fact, near the stirrup, but when the stirrup ripped out, it pulled off the trim strip and ripped out the trim screws, too. I didn't replace them - there seemed no reason.

However, there are a number of screws that penetrate the sidewall of the tube from the TM interior. Your new steel strap has to slide under all these protruding screw points - and in mine it did so quite easily.

Re caulking - yes, you have to cut and remove the factory- installed bead. I have no idea what kind of caulk they used except that when I removed it, it was squishy and stretchy like silicone caulk, and that it what I replaced it with.

BTW, when I called the factory, they told me that the reason the stirrup ripped out is that I didn't have the corner latches screwed down tight enough. I cranked 'em down a couple turns, and I can see that this might make a difference. The factory also offered to send me their mod kit.

Good luck.

Bill