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  #1   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm
  #2   Report Post  
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Grumman-581
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"Richard J Kinch" wrote in message
. ..
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:


I would think that welding a 2" receiver hitch receptacle to the bottom of
the angle bracket would give you more flexibility... It would lower the
trailer tongue enough that you probably wouldn't have to worry about your
door hitting it... If your vehicle is lifted, you could use a 2" receiver
with a drop so that the trailer could be towed in a more level attitude...
You would also have the option to use the 2" receiver for a bike rack or
cargo carrier...


  #3   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Grumman-581 writes:

I would think that welding a 2" receiver hitch receptacle to the
bottom of the angle bracket would give you more flexibility.


Agreed. I may modify it later like you say, but for now I just wanted the
minimum cost and effort to tow a small boat, improvising a step bumper like
on a pickup truck.

Bumper-mounting a 2-inch receiver strikes me as an awkward combination,
like hanging an oxen yoke on a pony.
  #4   Report Post  
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Grumman-581
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"Richard J Kinch" wrote in message
. ..
Bumper-mounting a 2-inch receiver strikes me as an awkward combination,
like hanging an oxen yoke on a pony.


Which group are you posting from so I can drop the crossposting to the
other... I'm in r.a.m.j+w...

The thing is, it gives you a lot more flexibility for other attachments that
you don't have with smaller receivers or just a bumper hitch... It also
gives you the option for a receiver mounted winch that you could move from
the front to the rear (assume that you also did the same thing on the front
bumper)... I've been considering mounting 2 extra 2" receivers on my rear
bumper and making a custom cargo carrier such that it would have three 2"
supports that would slide into the three receivers... That would make for a
'ell of a sturdy cargo carrier...

The bumper mounted 2" receivers that I've seen previously also have a 45"
piece of plate steel welded on both sides of the 2" receiver to the mounting
plate so that it will provide more resistance to twisting... Probably more
of an issue with a cargo carrier than a trailer...


  #5   Report Post  
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Gunner
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

On Wed, 25 Jan 2006 07:16:53 GMT, "Grumman-581"
wrote:

"Richard J Kinch" wrote in message
...
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:


I would think that welding a 2" receiver hitch receptacle to the bottom of
the angle bracket would give you more flexibility... It would lower the
trailer tongue enough that you probably wouldn't have to worry about your
door hitting it... If your vehicle is lifted, you could use a 2" receiver
with a drop so that the trailer could be towed in a more level attitude...
You would also have the option to use the 2" receiver for a bike rack or
cargo carrier...

I agree. Well said.

Gunner

"Deep in her heart, every moslem woman yearns to show us her tits"
John Griffin


  #6   Report Post  
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Tomes
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Nice and simple. The thing I am worried about is the strength of the
connection between the bumper and the Jeep itself.
Tomes

"Richard J Kinch" wrote in message
. ..
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm



  #7   Report Post  
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RoyJ
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

The bumper on the Wrangler is not not strong enougth for trailer loading
to the 2000 pound towing capacity of the Jeep (assuming you have the
6cyl and 2000 pound rated capacity)

I'm fairly certain that I could grab a 2' pipe wrench and give that
hitch a good flexing without too much trouble.

Richard J Kinch wrote:
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm

  #8   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

RoyJ writes:

The bumper on the Wrangler is not not strong enougth for trailer loading
to the 2000 pound towing capacity of the Jeep (assuming you have the
6cyl and 2000 pound rated capacity)


I guess you didn't actually read the page, where I say as much.

The point is to get *some* capacity without spending $150 for a real frame
hitch and drawbar.
  #9   Report Post  
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cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

I don't think I would trust the stock bumper on a TJ to pull anything.
When I ordered my 2000 TJ with towing package it had a separate tube and
receiver mounted off of the frame rails and not to the bumper itself
as they told me it would not hold up to towing....... it is very thin
channel that is mounted to the cross member mainly and not the frame. I
would be very leery about doing this. Nice design though...

Tom

"Richard J Kinch" wrote in message
. ..
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm



  #10   Report Post  
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Dave Milne
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

I have the mopar towbar - it attaches to the frame at 6 points using 1/4"
plate. Pretty substantial.

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ

"cantrelm" wrote in message
...
I don't think I would trust the stock bumper on a TJ to pull anything.
When I ordered my 2000 TJ with towing package it had a separate tube and
receiver mounted off of the frame rails and not to the bumper itself
as they told me it would not hold up to towing....... it is very thin
channel that is mounted to the cross member mainly and not the frame. I
would be very leery about doing this. Nice design though...

Tom

"Richard J Kinch" wrote in message
. ..
Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm







  #11   Report Post  
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Mike Romain
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Richard J Kinch wrote:

Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm

  #12   Report Post  
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Grumman-581
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"cantrelm" wrote in message
...
I don't think I would trust the stock bumper on a TJ to pull anything.


Yeah, it does seem a bit flimsy, like the original bumpers on my XJ...
Perhaps his next project should be to design a real bumper for his TJ that
utilizes the original bumper's mounting points in addition to the mounting
points for the factory receiver hitch... Make the entire bumper out of 1/4"
steel so that you can jack the car up with it... Might as well consider
closing off parts of it for an emergency air tank also...


  #13   Report Post  
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Earle Horton
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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" wrote in message
...
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/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Richard J Kinch wrote:

Here is my design for a bumper-mounted Jeep Wrangler TJ trailer hitch:

http://www.truetex.com/jeep_trailer_hitch_bracket.htm



  #14   Report Post  
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cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

That is what I am doing. Making my own swing arm bumper, with a 2" hitch
receiver in the middle of the bumper tube..... These pictures don't have the
hitch cut and welded in yet, but it will be dead center of the main bumper.
The whole thing will bolt to the frame rails where my current hitch bolts
now and also use the crossmember mounts that the standard bumper has.
http://www.cantrell.com/scrap/bump1.jpg
http://www.cantrell.com/scrap/bump2.jpg
I am putting a hi-lift jack mount on there also.

Tom


"Grumman-581" wrote in message
...
"cantrelm" wrote in message
...
I don't think I would trust the stock bumper on a TJ to pull anything.


Yeah, it does seem a bit flimsy, like the original bumpers on my XJ...
Perhaps his next project should be to design a real bumper for his TJ that
utilizes the original bumper's mounting points in addition to the mounting
points for the factory receiver hitch... Make the entire bumper out of

1/4"
steel so that you can jack the car up with it... Might as well consider
closing off parts of it for an emergency air tank also...




  #15   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Mike Romain writes:

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...


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


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.


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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Grumman-581 writes:

Perhaps his next project should be to design a real bumper for his TJ ...


Bad idea. Bumpers are weaker than the frame so they absorb impact energy
instead of bending the frame. You put a heavy bumper (or a frame hitch for
that matter) on the back of your car, and many collisions are going to
result in frame damage that would have just been a simple bolt-on swap of a
new bumper.

On a previous rear-ended TJ I was able to replace a crunched back bumper
with a $25 OEM item from eBay (surplus to somebody's aftermarket upgrade)
with hand tools. The other guy had $1000s in damage.

I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?
  #17   Report Post  
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Grumman-581
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"Richard J Kinch" wrote in message
. ..
I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?


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... evil-grin


  #18   Report Post  
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Mike Romain
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Richard J Kinch wrote:

Mike Romain writes:

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...


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


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.

  #19   Report Post  
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Stephen Young
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Richard J Kinch wrote:


I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?


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.
  #20   Report Post  
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billy ray
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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?


"Richard J Kinch" wrote in message
. ..
Mike Romain writes:

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...


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


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.





  #21   Report Post  
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billy ray
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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..



Richard J Kinch wrote:


I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?



  #22   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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:

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.


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.

My first concern was your use of four 3/8 inch bolts to hold the angle
iron to the bumper.


Why a concern? The working strength of a 3/8 bolt exceeds the rest of
the components. and the applied loads.

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?


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.
  #23   Report Post  
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Larry Jaques
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

On Wed, 25 Jan 2006 23:56:17 GMT, with neither quill nor qualm,
"Grumman-581" quickly quoth:

"Richard J Kinch" wrote in message
...
I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?


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... evil-grin


That's what happened to the Toyota station wagon that hit my F-150
dock bumper. It shortened the Toy by ONE FOOT and it gave my right
rear fender a 1/2" deep 2.5" diameter ding as well as scratching the
dock bumper paint. Luckily, I had the rear slider open and it kept
my head from going through the back glass. Both pieces of glass bowed
and acted as a spring to limit my whiplash vs. killing me. I'm just
glad I was still doing 35mph when she hit me at 65. How she missed
seeing 30 cars with their brake lights on (+ my full-sized pickup)
I'll never know.

MASS, not crumple zone, is the winner in a vehicular accident. Trucks
usually win over cars and smaller trees. Y'all can keep your Geo
Metros and other crumple-zone tin cans.


---
Annoy a politician: Be trustworthy, faithful, and honest!
---
http://www.diversify.com Comprehensive Website Development
  #24   Report Post  
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cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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

"Richard J Kinch" wrote in message
. ..
Grumman-581 writes:

Perhaps his next project should be to design a real bumper for his TJ

....

Bad idea. Bumpers are weaker than the frame so they absorb impact energy
instead of bending the frame. You put a heavy bumper (or a frame hitch

for
that matter) on the back of your car, and many collisions are going to
result in frame damage that would have just been a simple bolt-on swap of

a
new bumper.

On a previous rear-ended TJ I was able to replace a crunched back bumper
with a $25 OEM item from eBay (surplus to somebody's aftermarket upgrade)
with hand tools. The other guy had $1000s in damage.

I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?



  #25   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Mike Romain
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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 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/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

cantrelm wrote:

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

"Richard J Kinch" wrote in message
. ..
Grumman-581 writes:

Perhaps his next project should be to design a real bumper for his TJ

...

Bad idea. Bumpers are weaker than the frame so they absorb impact energy
instead of bending the frame. You put a heavy bumper (or a frame hitch

for
that matter) on the back of your car, and many collisions are going to
result in frame damage that would have just been a simple bolt-on swap of

a
new bumper.

On a previous rear-ended TJ I was able to replace a crunched back bumper
with a $25 OEM item from eBay (surplus to somebody's aftermarket upgrade)
with hand tools. The other guy had $1000s in damage.

I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?



  #26   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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.
http://www.cantrell.com/scrap/jack1.jpg

Tom


"Stephen Young" wrote in message
...
Richard J Kinch wrote:


I wonder if people buying all those macho aftermarket bumpers understand
that they've *given up* a lot of their crash protection?


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.



  #27   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

cantrelm writes:

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?


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.
  #28   Report Post  
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Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Mike Romain writes:

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


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.
  #29   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
billy ray
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ


The last time I hauled a rubber boat it was atop my WJ.... How dangerous was
that?



Please, I'm just trying to get my toy boat and waverunner trailer 6 miles
down to the beach.



  #30   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Andrew VK3BFA
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ


billy ray wrote:
The last time I hauled a rubber boat it was atop my WJ.... How dangerous was
that?



Please, I'm just trying to get my toy boat and waverunner trailer 6 miles
down to the beach.


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.



  #31   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Earle Horton
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"Andrew VK3BFA" wrote in message
oups.com...
---snippy---
- could I humbly suggest that a sticker saying
"max towing weight 1,000lbs" be put on the thing? -

I like this one. http://tinyurl.com/cel57

Earle


  #32   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Good one Earle.

Tom

"Earle Horton" wrote in message
m...
"Andrew VK3BFA" wrote in message
oups.com...
---snippy---
- could I humbly suggest that a sticker saying
"max towing weight 1,000lbs" be put on the thing? -

I like this one. http://tinyurl.com/cel57

Earle




  #33   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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


"Richard J Kinch" wrote in message
.. .
cantrelm writes:

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?


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.



  #34   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Andrew VK3BFA writes:

could I
humbly suggest that a sticker saying "max towing weight 1,000lbs" be
put on the thing?


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.
  #35   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Richard J Kinch
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

cantrelm writes:

If the bumper were suitable for load-bearing then why does Jeep not sell
this simple little option.


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).


  #36   Report Post  
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cantrelm
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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

Tom



"Richard J Kinch" wrote in message
. ..
cantrelm writes:

If the bumper were suitable for load-bearing then why does Jeep not sell
this simple little option.


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).



  #37   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
Mike Romain
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Richard J Kinch wrote:

Andrew VK3BFA writes:

could I
humbly suggest that a sticker saying "max towing weight 1,000lbs" be
put on the thing?


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.


Bull crap.

You are attaching a trailer to sheet metal that 'I' am capable of
bending back into shape by hand.

Overbuilding an attachment point is a safety thing. Off road stresses
can be amazingly high. Putting an attachment point on sheet metal is
almost criminal. Well, it 'is' criminal up here in Canada to have an
under rated trailer hitch.

The rental places won't rent to soft top vehicles. This is because of a
serious CO safety issue when the exhaust vortexes between the back of
the Jeep and the trailer.

I know there is no talking sense to you. I just hope you don't go out
and kill someone.

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/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
  #38   Report Post  
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Grumman-581
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

"cantrelm" wrote in message
. ..
If the bumper were suitable for load-bearing then why does Jeep not sell
this simple little option.


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

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,


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?


  #39   Report Post  
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billy ray
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

Maybe you need something like this:
http://www.imagestation.com/album/pi...2772921&idx=40


"Richard J Kinch" wrote in message
. ..
Andrew VK3BFA writes:

could I
humbly suggest that a sticker saying "max towing weight 1,000lbs" be
put on the thing?


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.



  #40   Report Post  
Posted to rec.autos.makers.jeep+willys,rec.crafts.metalworking
billy ray
 
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Default Bumper-mounted trailer hitch bracket for Jeep Wrangler TJ

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...


"Grumman-581" wrote in message
...
"cantrelm" wrote in message
. ..
If the bumper were suitable for load-bearing then why does Jeep not sell
this simple little option.


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

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,


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?




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