U-Bolts breaking during installation

valhalla360 wrote:
This is silly, show some pictures or name the model.

I haven't seen u-bolts on a frame mounted hitch, nor have many of those responding, so share some details so we can provide a more useful response.

Typical thread here, where OP throws out some bread crumbs and then watches folks try to guess what is going on and half the responders are totally confused when they respond....

covered wagon wrote:
Need double nuts too so they're locked tight and stay tight. That's important with temperature changes and vibration.

No, you don't and if temperature changes and "vibration" loosen your hitch receiver, you have other issues that a double nut won't cure.
(Double nut IS one solution when necessary, but when is the last time you saw an OE application of anything on a vehicle in a double nut configuration? Of course, there are many other, cleaner ways to accomplish the same thing.)
And has nothing to doo with the OP's issue.

With him having to drill the holes in the frame he must have a universal type hitch. I've not seen a hitch designed for a specific application needing holes drilled. An engineer should be able to figure that out. It sounds like someone trying make do with a cheap set up

This is silly, show some pictures or name the model.

I haven't seen u-bolts on a frame mounted hitch, nor have many of those responding, so share some details so we can provide a more useful response.

Need double nuts too so they're locked tight and stay tight. That's important with temperature changes and vibration.

Stratacter wrote:
The manufacturer is a major supplier of trailer hitches, but I won't reveal the company because I'm waiting for them to respond to my inmail on their website. I carefully followed their installation instructions. Also, I'm a Senior Engineer by trade, so I know what I'm doing.

The primary lateral support for the hitch is from the 2 square U-bolts that are fed through four 1/2" holes drilled into the two frame rails that hold the bumper shocks. I drilled the 1/2" holes to match and line up with the hitch holes. Four nuts with 4 conical washers are supposed to attach to the 2 U-bolts to hold the hitch arms tightly against the frame rails, with each nut tightened to 45 ft-lbs.

In my case, I hand tightened the nuts and then proceeded to tighten (with torque wrench) the first nut, and POW, it broke before it reached 45 ft-lbs. Apparently, the square U-bolt was not Grade 8, and the parts list confirmed this. Only the bolts and nuts holding the front of the hitch to the bumper shock frames, as well as the nuts for the U-bolts are Grade 8.

I decided to bolt the hitch, as per the directions, instead of having it welded on, because I'll only use it to support a platform with bicycles, not pulling a camping trailer or anything really heavy.

I hate to think about how many hitches like this were sold and installed, with their U-bolts about to break and cause a serious accident. Many probably already have.

Any recommendations?

It would help if you also posted a couple pictures. Is this hitch being installed on the back of a trailer for a bike rack, or back of the TV.

Gdetrailer wrote:

Stratacter wrote:
The manufacturer is a major supplier of trailer hitches, but I won't reveal the company because I'm waiting for them to respond to my inmail on their website. I carefully followed their installation instructions. Also, I'm a Senior Engineer by trade, so I know what I'm doing.

The primary lateral support for the hitch is from the 2 square U-bolts that are fed through four 1/2" holes drilled into the two frame rails that hold the bumper shocks. I drilled the 1/2" holes to match and line up with the hitch holes. Four nuts with 4 conical washers are supposed to attach to the 2 U-bolts to hold the hitch arms tightly against the frame rails, with each nut tightened to 45 ft-lbs.

In my case, I hand tightened the nuts and then proceeded to tighten (with torque wrench) the first nut, and POW, it broke before it reached 45 ft-lbs. Apparently, the square U-bolt was not Grade 8, and the parts list confirmed this. Only the bolts and nuts holding the front of the hitch to the bumper shock frames, as well as the nuts for the U-bolts are Grade 8.

I decided to bolt the hitch, as per the directions, instead of having it welded on, because I'll only use it to support a platform with bicycles, not pulling a camping trailer or anything really heavy.

I hate to think about how many hitches like this were sold and installed, with their U-bolts about to break and cause a serious accident. Many probably already have.

Any recommendations?

Just guessing, something like this idea?



Or any hitch that mounts via U bolts for that fact.

Get your money back..

Even if the U bolts were to hold, you are risking crushing the frame.

A better way although still less than ideal if you are dealing with a box or tube frame would be this way..



Which uses a heavy steel plate to act as reinforcement and separate bolts. Of coarse you still risk crushing box or tube frame but if you use bolts with short threads you could limit some of the crushing.

You could have a heavy plate fabricated, but unless you have the equipment to cut and drill heavy plate the cost to pay someone would exceed the cost of a better hitch..

I would say NO, this is not what he is using. He stated Bumper shocks in his post, so that leads me to believe Car/Van, not a SUV or Trailer. Doug

Stratacter wrote:
The manufacturer is a major supplier of trailer hitches, but I won't reveal the company because I'm waiting for them to respond to my inmail on their website. I carefully followed their installation instructions. Also, I'm a Senior Engineer by trade, so I know what I'm doing.

The primary lateral support for the hitch is from the 2 square U-bolts that are fed through four 1/2" holes drilled into the two frame rails that hold the bumper shocks. I drilled the 1/2" holes to match and line up with the hitch holes. Four nuts with 4 conical washers are supposed to attach to the 2 U-bolts to hold the hitch arms tightly against the frame rails, with each nut tightened to 45 ft-lbs.

In my case, I hand tightened the nuts and then proceeded to tighten (with torque wrench) the first nut, and POW, it broke before it reached 45 ft-lbs. Apparently, the square U-bolt was not Grade 8, and the parts list confirmed this. Only the bolts and nuts holding the front of the hitch to the bumper shock frames, as well as the nuts for the U-bolts are Grade 8.

I decided to bolt the hitch, as per the directions, instead of having it welded on, because I'll only use it to support a platform with bicycles, not pulling a camping trailer or anything really heavy.

I hate to think about how many hitches like this were sold and installed, with their U-bolts about to break and cause a serious accident. Many probably already have.

Any recommendations?

Just guessing, something like this idea?



Or any hitch that mounts via U bolts for that fact.

Get your money back..

Even if the U bolts were to hold, you are risking crushing the frame.

A better way although still less than ideal if you are dealing with a box or tube frame would be this way..



Which uses a heavy steel plate to act as reinforcement and separate bolts. Of coarse you still risk crushing box or tube frame but if you use bolts with short threads you could limit some of the crushing.

You could have a heavy plate fabricated, but unless you have the equipment to cut and drill heavy plate the cost to pay someone would exceed the cost of a better hitch..

A company that can sell something like that, placing people's lives at risk, isn't going to get back to you or at the very least will feed you a line of double talk.

You need to return that hitch and get a good name brand. Always go for the best on something this important. I could not trust a company that hasn't thoroughly tested their product esp. a hitch.

You just joined. To get the BEST info, you need to state what year and model Truck/van/car or motorhome you have. AS I stated, I have never seen u bolts used for a hitch in 43 years as an RV tech. I HAVE seen U bolts used for add on hitches that are not really rated. This includes 4 inch square bumpers on the rear of trailers that do use u bolts. But you state to the frame mount. Usually you have enough clearance to use regular bolts and not u bolts. Can you use regular bolts in place of the u Bolts? If so, this would be the BEST solution to your mount. Regardless of the U bolts. BTW, there have been numerous recalls(federal) over the past 30 years on REGULAR Motorhome bolted on Hitches from the OEM RV maker, due to wrong grade bolts used and also inadequate welds. This is different brands of hitches. So, listing the brand of hitch is not a real concern, and IF this is a problem across hundreds or thousands of these hitches, it would be a big help for some out there to realize they may have to check their hitches. Also, just posting the Brand you are having a problem with would not be a Libel concern. You are just stating what problem you had and are not disparaging the brand. Doug