Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ - Page 4

cantrelm writes:


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.

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

cantrelm writes:


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).

Richard,
"Not probative." oh please.
I really hope your arrogance does not get someone hurt.

Tom

One thing that I noticed that I would at least re-engineer a bit was the
fact that it appears that his hitch plate does not have a backing plate
behind the thin metal of the Jeep bumper... I would think that he should at
least have a backing plate as large as the hitch plate inside the bumper to
distribute the load across a greater area... An even better idea might be to
have this backing plate large enough to traverse the full with of the
bumper... Once you're at that point, maybe you should even consider having
this 'backing plate' tie in to the frame of the vehicle... Of course, by
this point, it would have probably been easier to just build a real bumper
from scratch... <grin>


Not a good analogy... These are the same engineers who designed the
problematic manifold that cracks and the motor mount bolts that haved
sheered off on my XJ multiple times?

Who has the video of a rear bumper being ripped off while attempting to pull
another vehicle out of the snow alongside the road?

I saw a link to it sometime in the last 6 months or so...

Billy,
I think you are referring to this video.
http://dtu.ifh.dk/Jokes/Film/web/snowtowcar.mpg.html

Tom

This one's funny...
http://dtu.ifh.dk/Jokes/Film/web/topbike.mpeg.html

Well.... there is no Jeep in that one but it is a good illustration on the
strength of bumper supports..

Grumman-581 writes:


A (smaller) backing plate is only a glorified washer, good only against
shearing through the attachment point. The rest of the bumper will have
failed before that happens, so it adds nothing.

A larger backing plate would be tantamount to replacing the bumper with a
stronger cross-member, and at that point you might as well put on a frame-
mounted hitch instead of using the bumper.

If you get pulled over by the highway patrol, you will/should get busted
for something as dumb as that.  Not meaning to be a jerk or anything but
Wow...

The bumper isn't rated for towing or even jacking up under so
technically that is an illegal hitch, let alone an unsafe one.

The TJ bumper isn't even strong enough to tow a TJ out of a snowbank
without bending or tearing off, let alone pulling almost the 'legal'
limit that the TJ can handle which is 2000 lb.  Your 1000 lb boat, plus
trailer, plus gear inside is easily the limit.  

Sorry man, it just isn't a good idea.

Just FYI, even the expensive 2" receiver bumpers with the 2" hitch built
in have a warning on them that says they are 'not' legal for towing,
only legal for putting a bike rack or some other type of rack into.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Richard J Kinch wrote:

Mike, you're in Canada.  I once passed an accident scene, where failure to
use safety chains, led to a boat trailer coming loose from the tow vehicle,
jumping through an oncoming vehicle's windshield and killing the driver.
The driver of the tow vehicle got a faulty equipment citation, but was
allowed to hook up again and drive home!  On the way back from wherever I
had been going, I saw him hooking up the trailer, with help from the state
patrol.  Now the law in Colorado says, that safety chains are required, and
legally a manslaughter prosecution would not have been out of line here.  It
didn't happen.  Maybe the guy paid a fine, but I doubt it.

That is one of the things, that helped me decide to move to western
Colorado.  The law is the same there, but the number density of jerks like
that is less, and you have more chances to avoid them.

I have one of those bumpers you are talking about.  I use it for a bike
rack.

Earle

Mike Romain writes:


Jerk or not, your legal opinion is baloney.

http://www.google.com/search?q=florida+statutes+316.530

Show me where hitch ratings have any legal significance in traffic laws.


The stock bumper is essentially a 3 x 4.5 inch 3.5-sided 13 gage steel
box beam 50 inches long.  Maybe someone can calculate the strength of
this member.

We're talking about towing a small rig under 1000 lbs, not dragging the
universe behind.

My mechanical intuition is that it is plenty strong when properly
fitted.  It doesn't visibly flex when I jump on the step.

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 in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Richard J Kinch wrote:

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?

I had the 1000 lb rig out for a test drive tonight after I finally got
the wiring done.  No problems that I could detect.

billy ray writes:


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.

On Wed, 25 Jan 2006 00:57:53 -0600, Richard J Kinch


Possibly not legal, in Kalifornia at least.
But then Law Enforcement hasn't been enforcing little laws like this
very vigorously lately ;-)
(When was the last time anyone got stopped for misaligned headlights?)

...

"noneyabusiness" wrote in message

Mine are aligned perfectly... One lets me see what is in the ditch on the
right side of the vehicle, the other lets me see what is in the trees on the
other side...

I saw your family photo on your website... Damn man, you sure have a lot of
kids (9!!!)... Did you know that they have figured out what cause that these
days?  HINT -- It's not in the water...

     Real Jeeps have a triangular reinforced frame for mounted PTO power
equipment, of course it will hold a class three ball:
http://www.billhughes.com/temp/46JeepRear.jpg  Real riveted channel frame
like the commercial trucks use: http://www.billhughes.com/CJ2Frame2.jpg  
        God Bless America, Bill O|||||||O
mailto:LWHughes3rd@aol.com

Richard J Kinch wrote: