Depends upon the severity of the wreck... My experience has been that it caused thousands of dollars of damage to the other vehicle and just knocked some dirt off my bumper... Turns out that *his* vehicle was acting as the crumple zone for *my* vehicle...
Good lord, how much do you weigh if you think 'you' can test the strength of a bumper by jumping on it?
You 'are' talking towing something the legal limit for the vehicle, on your website, 'not' a trailer and load under 1000 lb at all, but a 1000 lb boat 'plus' a trailer and most folks put gear in the boat.....
I got pulled over in Canada using a real DOT 'certified' trailer hitch that wasn't rated heavy enough for the trailer I was pulling and I was forced to drop the trailer on the road and wait for a tow truck at 3:00 AM. The cop luckily knew my passenger so didn't write me up the $1000.00 in tickets he itemized for me....
You are talking about an unrated homemade hitch on a bumper that is not tow rated at all. Phone your local DOT or highway patrol and ask about that...
I don't really care, but a little shot of safety reality has to be mentioned before too many people go out and copy your bad idea. This is a world wide web after all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
My 1995 K1500 has a brushguard/grilleguard mounted on the front. Bought the truck used & outfitted this way. Last year a silly juvenile female pulled out in front of me from a side street - her fault & she got ticketed. Totaled her Neon. I drove away with no radiator damage or drivability problems because that brushguard crushed sideways. Saved me big bucks & aggravation until I got it fixed.
Richard,
I think the reason for all the messages of concern you are receiving is that most of us have seen far too many bumpers seemingly hanging on by the strength of prayers and rust.
Bumper hitches were popular... decades ago when vehicles had substantial bumpers.
The auto industry then went through a period where "bumpers" were little more than chrome decoration bolted ONLY to sheet metal or fiberglass and years where they were constructed of metal so thin that they could be twisted by bare hands. I personally witnessed a bus driver twist, with his bare hands, a AMC Gremlin bumper straight after a minor collision.
I don't know what the bumper attachments for your Jeep are but I know what they look like in XJs and WJs and would personally feel uncomfortable hauling a trailer bolted solely to the bumper.
My first concern was your use of four 3/8 inch bolts to hold the angle iron to the bumper. When I installed a frame hitch on my XJ I used eight 1/2 inch stainless steel grade 5 bolts. I fully understand this was overkill but I received additional reassurance by the expenditure of an additional $2.40
As an engineer you were certainly trained to design a product for it intended use and then imagine what a complete moron might try to do with it and calculate a sufficient safety factor.
You intent is to never tow anything more than your 1000 pound inflatable boat/trailer. I will accept based on your education that it is properly designed for that load. What about when your kids use it to pull the homecoming parade float or your neighbor uses it to pull a trailer full of gravel?
Most of the ones distributed by the big names (Warn, ARB, etc) are designed to work with newer vehicle crash equipment and airbags.... at least that is what they claim..
On the TJ the stock bumper mounts are substantial with nicely welded seams to the box. They appear stronger than the rest of the bumper.
Why a concern? The working strength of a 3/8 bolt exceeds the rest of the components. and the applied loads.
It is first-grade towing sense that you don't hook up loads larger than the lowest-rated component of the tow vehicle (GTWR, hitch, drawbar, etc), which in this case is a conservative 1000 lbs for a shop-built bracket system.
If one holds that you should not install a hitch with a lower capacity than an ignorant or careless user might someday attempt, then there is no such hitch.
Richard, in your article you make a point of saying "I used Grade 5 bolts since ungraded hardware is not suitable for load-bearing applications. " You do realize that the bumper you are attaching to is only 3/32" thick and is not rated for load bearing applications....... This is somewhat of a contradiction don't you think?
Tom
Thanks, But the real question is when will this one be ready (lol) I have been working on it when I get breaks at work and so far it has taken me about 6 months. I still have to do the safety tow plate under the hitch and all the mounting brackets. Even as sturdy as this one is I am concerned about towing my trailer with it and it is made out of 1/4" x 3" x 4" rectangular tubing with 1/4" mounting brackets to the frame rails. This thing Richard has come up with is mounted to a piece of sheet metal that is only 3/32" thick........Glad I don't live in Florida......
Richard, please don't think that I am flaming you.....I am just concerned about the people behind you.....Remember that one ounce of prevention is worth a pound of cure.....
Tom
Richard J Kinch wrote: > twaldron writes: >
True, that's why I have an integrated bumper/hitch. Zero clearance issues.
tw _____________________________________________________________________
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco"There is a very fine line between 'hobby' and 'mental illness'."
Pronunciation: 'jEp Function: noun Date: 1940
Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase') A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton capacity and four-wheel drive used by the U.S. army in World War II. _____________________________________________________________________
I'll bet he also didn't think about what happens if he front ends someone while pulling the trailer. He will have a thousand pound plus spear running right through that sheet metal bumper, right through the door, seat and anything/body else in it's way...
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >Stephen, I have to agree. I made a front brushguard for my Jeep and a week after getting it on I got rear-ended and launched 4 feet forward and up under the back of a flat bed truck. Only thing that it did to the Jeep was scratch off some powder-coating on brushguard. The guy that hit me had to have a new grill and hood. Had it not been for my guard I would have had to have all that too. Here is a pic of guard.
The bumper is suitable for load-bearing, for a suitable load.
One problem I understand with ungraded bolts sized about 1/2 inch or smaller is that hand-tightening torque can stress the shaft close to the working limit, leaving not enough strength for the applied load. This is not an issue for the bumper itself.
Between the coupler and the vehicle interior is 40 square inches of 3/8 steel, and a beefy frame cross-member in front of that.
In such a collision, I would expect the rubber boat is going to be ripped off its hold-down straps, launch forward, hit the back of the car, bounce off and pitch-pole over the car.
Of course, if you want to start postulating arbitrarily forceful collisions, then some scenario is going to have a trailer axle or something through my eye socket.
Please, I'm just trying to get my toy boat and waverunner trailer 6 miles down to the beach.
The last time I hauled a rubber boat it was atop my WJ.... How dangerous was that?
Can I throw in my 10 cents worth here?. I am NOT an engineer - I saw the drawing, thought, MM, thats looks pretty cool. Subsequent discussion here tells me it is not. How would I know otherwise ? - I dont have the depth of engineering knowledge to see what looks like a reasonable trailer hitch and know that I should be careful? - could I humbly suggest that a sticker saying "max towing weight 1,000lbs" be put on the thing? - yes, Richard, you designed and built it for a specific application, you know what NOT to do - but what about the next owner? - they wont know.....
This is one of the resons that there are standards - not only to (try to) protect the stupid, but also the rest of us who dont have a high degree of knowledge and skill in fields other than their own. And, in this case, I readily admit to being one of those ignorant people. My field is electronics, not mechanical or automotive engineering.
But it was a nice posting - know a bit more about the subject now, so thanks folks - glad groups like this are around....
Andrew VK3BFA.
---snippy---
I like this one.
Good one Earle.
Tom
Richard, If the bumper were suitable for load-bearing then why does Jeep not sell this simple little option. I have to say that I am impressed with your web page, you have lots of nice stuff on there and seem to be a guy that is somewhat intelligent, but this is not one of your better ideas. There is a reason you can not buy a Jeep with a bumper hitch option on it. I would think that the Jeep engineers know what they are doing, and if you want towing on a Jeep it comes with a separate (mopar) draw hitch attached directly to the frame rails and not the cross member. These components were not designed for this application plain and simple....... I am no engineer but I do work with metal every day, (build poultry processing equipment) and I have seen what can happen to 3/32" steel when a load is applied, trust me it does not take much to rip this stuff in half. I wish you luck with it and I hope that no one ever gets hurt from what I think is a bad idea. If you would like I would be glad to sell you my 1 1/4" receiver hitch (mopar
1000lbs on 4 cylinder, 2000lbs on 6 with a max tongue of 200lbs) after I have finished my bumper that I am currently in the process of making....... I would let you have it for a very reasonable price if it means that you would take that thing off and never let it see the light of day again.......Tom
If it ever came down to a situation where someone would read it, and heed it, then I might do something like that. For my personal use, why bother. (On the other hand, I've never had much use for that steel punch stamping kit, maybe I'll stamp it on there for that Canadian trip someday, heh heh.)
This whole culture of Jeep hitches has me baffled. People insist on putting class III hitches on a short-wheelbase soft-top vehicle that dubiously purports even a minimal 2000 lb capacity. The guys who also have the jacked-up suspensions, cheating death with their unstable aftermarket mods, are the extreme version of this.
THere is a kind of "impedance matching" optimization to this type of design, and I believe I've approximated it for the intended application.
Not probative. I recall they didn't sell any kind of hitch option for a long time; it was all unendorsed aftermarket stuff.
Last I checked, U-Haul won't even rent you a trailer for a Jeep, no matter what hitch you have.
Trailering on a Jeep is a problematic compromise (when it is not a religious absolute in some minds).
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