U-bracket for WD bars ... issue with self tapping screws

BarneyS wrote:

path1 wrote:
Your talking about the snap up brackets right?

Why do you want the brackets held in place so tight they break the screws? It needs room to move back and forth when turning. No wonder the screws break.

Of course, using or not using mounting screws to hold bracket on will be the same thing as to grease your ball or not.

The snap-up brackets are not supposed to move back and forth when turning. That is the reason for using at least 5 links of chain between the bracket and the bar. Doing this will allow the bar to move back and forth without dragging the snap-up bracket with it.

There is nothing wrong at all with bolting the snap-ups in place. Many do it, especially if they have heavy tongue weights. Most snap-ups are just placed over the A frame and lightly held in place with the large pinch bolt on the inside of the frame. That bolt is intended to help keep it from sliding during turns. The downward pressure from the WD bars keeps it on the A frame.
Barney

We must have different brands... Mine say nothing about mounting the brackets being bolted or five links. I call e-trailer when I first got this set up, and was informed that some TT's have a problem with propane tank holder hitting if not bolted down and others just feel happier bolted down.

http://manuals.adventurerv.net/Eaz-Lift-Weight-Distribution-Hitch-Elite-Instructions.pdf

"AFTER HOOKING UP
Spring bar should be parallel with trailer frame, or a slight angle up or down." says nothing about five links.

I'd rather not drill holes in my A frame.

westend wrote:
Those self-tapping/self threading bolts are the devil. Seems to be the way of the world with fasteners these days. I see many different fasteners in different products and most of them are so soft that any extra force tears them up instantly. I assume that these soft-body fasteners are imported from overseas but I don't give US mfgs any more respect than what they deserve, either.

Especially on the smaller sizes. Just replaced the ones in the tongue area, only to have one break less than a week later. Pffft. At least the tips have a flat that you can use a wrench on to remove.

The other bad thing about them is the plating quality. They rust in no time flat. Most of the ones under our TT were rusty less than a year. Probably getting it delivered in the winter doesn't help with salt on the road. Another project some day will be replacing them, maybe with stainless. But are stainless steel just as weak?

Those self-tapping/self threading bolts are the devil. Seems to be the way of the world with fasteners these days. I see many different fasteners in different products and most of them are so soft that any extra force tears them up instantly. I assume that these soft-body fasteners are imported from overseas but I don't give US mfgs any more respect than what they deserve, either.

path1 wrote:
Your talking about the snap up brackets right?

Why do you want the brackets held in place so tight they break the screws? It needs room to move back and forth when turning. No wonder the screws break.

Of course, using or not using mounting screws to hold bracket on will be the same thing as to grease your ball or not.

The snap-up brackets are not supposed to move back and forth when turning. That is the reason for using at least 5 links of chain between the bracket and the bar. Doing this will allow the bar to move back and forth without dragging the snap-up bracket with it.

There is nothing wrong at all with bolting the snap-ups in place. Many do it, especially if they have heavy tongue weights. Most snap-ups are just placed over the A frame and lightly held in place with the large pinch bolt on the inside of the frame. That bolt is intended to help keep it from sliding during turns. The downward pressure from the WD bars keeps it on the A frame.
Barney

Normally you don't bolt the snap up brackets on unless you have high tongue weight for that model Salem TT, which might have a TW of 900-1,000 lbs I don't *think* you need to bolt the brackets on? Have you had issues with the brackets that require them to be bolted on?

What brand WDH and do you have the chains vertical or close to it? A photo or two would be helpful. If the chains aren't close to being vertical, when doing tight left/right turns (like when backing up), the ends of the spring bars can move far enough to pull a bracket forward or rearward and thus cause damage to the snap-up brackets. If you can't make the chains vertical, you can move the propane tanks forward which is easy to do.

Not sure how you can snap the head off a screw like that. The A-frame tubing wall thickness is only 1/8" and I don't know how you'd break a screw head that size and not strip the threads in the tubing first?? I'd be using at least a grade 5 screws (1/2"-13) and preferably a flange head one. Did you use a torque wrench?

I think you really need to use a thread-forming screw and not a self-tapping one. Self-tapping cuts the metal and thread-forming pushes the metal aside. When using a thread-forming screw, it stays in the material tighter but it's possible to over-tighten it. If using self-tapping screws, it's possible to strip the threads when removing a screw.

One option is to buy Reese thread-forming screws (1/2"-13) like in the photo along with Reese's rivnut kit (2nd photo). The rivnuts (aka rivet nut) require a clean/undamaged 11/16" dia. hole. With rivnuts, you can readily remove and re-install bolts/screws without causing damage. The rivnuts also allow a higher tightening torque - 75 vs 50 ft-lbs.

Another option would be to through-bolt the bracket in place by using a backer plate inside the A-frame tubing with nuts welded to it. You'd cut access openings in the cover plate at the rear ends of the A-frame. The 3rd photo shows what I did for our Reese cam arm brackets.

I would consider drilling all the way through and getting a longer grade 8 volt and use washers and nylon locking but in the other side. The brackets aren't designed to move. That is what the chains or slide bars are for.

Your talking about the snap up brackets right?

Why do you want the brackets held in place so tight they break the screws? It needs room to move back and forth when turning. No wonder the screws break.

Of course, using or not using mounting screws to hold bracket on will be the same thing as to grease your ball or not.

Pretty hard to judge fitment issues regarding a larger screw and the relationship to the bracket. If the new screw cut thread into the bracket, it may be OK.

The problem that I would foresee is that the bracket bears a lot of torque and bending moment while in use and the part function is critical to keeping something together while the vehicle is in motion. Failure of the screw and consequent detachment of the bracket causing a bar to come dislodged and fly off/dragged is a risk I wouldn't take. In fact, if the screw breaks from just attaching, it's probably a poor fastening system to start. Could you remove the self-trapper and use a through bolt? Maybe a grade six or better bolt would be a better solution.

Good luck with your WDH.

My previous TT had an opening at the front. They make nut and bolt sets where the nut has long wire attached. Don't recall the name but with the wire attached you can slide the nut inside the channel. After chinching it up tight cut the wire.