Worn Cobra rear-door hinges (both pin and hole)

Hi Steve - What do you think of the Cobra (aluminum)
pin into a bushing:
http://www.mcmaster.com/#5448T18
I was planning to do as you did, but it would be
much quicker to just add a bushing and replace
the pins.
Thanks in advance,
Best Regards, Dave "YO electric"

Dave-

Those bushings are intended to be pressed into solid material. I
ruled out trying to rely on the aluminum channel for the structure as
that was proven by me (and now you) not to work. I think you would
find it difficult to attach the bushing to the relatively thin
aluminum wall and have it stay put. Regarding your aluminum pin...
its obviously trashed like mine was and not usable in a bushing. If
you are going to have to replace the pin, steel would be a much better
choice. I recommend the scheme that I described previously.

Steve Koerner
www.wingrigger.com

Sorry, I wasn't clear...
I have new non-trashed (aluminum) pins from Spindelberger.
If I press bushings into channel, they can't move and
will stay in place in the channel, rubbing area on pin
is greatly increased, hopefully pin will not abrade as
it will against channel.
Your thoughts ?
Thanks,
Best Regards, Dave

Steve, would love to see some pictures of your mod it sounds ideal.

I have always thought that small pin fitting into a thin wall aluminum
channel was very
poor way of getting the job done.

I would also like to see what the "new" cobra setup looks like.

I have a machine shop and could possibly manufacture a few low cost
DIY kits for others.

Either Joe or Steve - I (and likely others)
would be interested in a kit; ideally new
pin plus insert that can be glued/riveted
inside the existing corner channel with
minimal surgery...
Let us know your thoughts,
Thanks,
Best Regards, Dave

Joe -- making some kits sounds like a great idea. Please make one for
YO so he doesn't try to stick a bushing in that aluminum channel.

For a long time I had intended to do a write-up on this mod but I
never got to it. I wish I had. I didn't locate any pictures but I
did locate my dimensioned sketch that I made at the time of
fabrication. From the date on the page,I did this in '06. Th sketch
is crude but it should be all you need to make the block that goes
into the channel. The block is 1.00" X .74" X 4.00". It has 3 M8
tapped holes in the bottom and the reamed .501" hole in the side. I
suppose there is the possibility that the skids are located at
different longitudinal locations on various trailers -- so that would
need to be checked first. It looks like I didn't make any sketch of
the part that goes on the door -- I'm thinking it was just an obvious
duplication of the existing part there but with the .500" steel pin in
place of the aluminum metric size pin.

If anyone makes one of these, you should put some grease on the pin or
in the hole when you put it together.

I have posted the sketch he
http://www.box.com/shared/3ul281v6y0aek31gmva5

Steve Koerner
www.wingrigger.com

On Saturday, December 17, 2011 12:51:02 PM UTC-5, Dave Nadler wrote:
Hi Folks - Anybody else had this problem ?
http://www.nadler.com/Antares/Cobra_...ge_closeup.JPG
I've got replacement pins from Spindelberger and
replacement rear corner channels, but I'm thinking
about an insert so all the loads aren't taken in
a thin bit of channel...
Thanks,
Best Regards, Dave "YO electric"

PS: ~55k miles on the trailer.

OK, lets recap, from thread here and private emails.

As it says above: I have NEW REPLACEMENT aluminum pins
and NEW REPLACEMENT (undrilled) corner channels
from Spindelberger.

I do not want to repeat the problem by using these
as used originally.

The structure (pins/channel) is STRONG enough, but
the aluminum pin on the thin aluminum corner channel
wears excessively. Aluminum-on-aluminum is NOT GOOD.

Suggestions so far via email and in this thread:

A bushing (as suggested by T8 and others) reduces
wear with a better fit and materials that wear less;
anything is better than aluminum-on-aluminum.

A replacement pin of steel (drill stock or cut
bolt with a couple holes through it for mounting;
no complicated machining required) will not wear
out so easily.

A steel insert, block or 1/4" plate bolted to
inside of channel, will give better wear and more
surface.

A tube insert (all the way through the corner channel)
can do likewise. Add a plastic cap on the outside
to keep the dirt out. Easy to make and install
(before riveting in replacement corner channel);
no complicated machining required.

Notes on more modern Cobra trailers:

The bottom of the existing corner channel is not
open; the sidewall extrusion is cut leaving this
area blocked. You cannot just slide a reinforcement
part in from the bottom; you have to remove the
corner channel (bunch of rivets).

The skids are mounted forward of the rear corner
channel.

Further thoughts ?
Thanks in advance,
Best Regards, Dave "YO electric"

http://www.onlinecontest.org/olc-2.0...l?dsId=2176944

On Dec 18, 8:07*pm, Steve Koerner wrote:
Joe -- making some kits sounds like a great idea. *Please make one for
YO so he doesn't try to stick a bushing in that aluminum channel.

For a long time I had intended to do a write-up on this mod but I
never got to it. *I wish I had. *I didn't locate any pictures but I
did locate my dimensioned sketch that I made at the time of
fabrication. *From the date on the page,I did this in '06. *Th sketch
is crude but it should be all you need to make the block that goes
into the channel. * The block is 1.00" X .74" X 4.00". *It has 3 M8
tapped holes in the bottom and the reamed .501" hole in the side. *I
suppose there is the possibility that the skids are located at
different longitudinal locations on various trailers -- so that would
need to be checked first. *It looks like I didn't make any sketch of
the part that goes on the door -- I'm thinking it was just an obvious
duplication of the existing part there but with the .500" steel pin in
place of the aluminum metric size pin.

If anyone makes one of these, you should put some grease on the pin or
in the hole when you put it together.

I have posted the sketch hehttp://www.box.com/shared/3ul281v6y0aek31gmva5

Steve Koernerwww.wingrigger.com

Back to the 'why' is the rear door hinge getting all chewed up? I'm
thinking the culprit is the heavy ramp (with jack ('s). The rear door
locks the ramp in place with a bolt that extends into the door when it
is closed. I have found (and fixed) the hole in the door that holds
the ramp, to be severely elongated, why? The ramp & jack are bumping
up and down causing the elongation. This becomes a jack-hammer and the
destructive action doesn't stop with elongating the ramp to door lock.
I believe it is undoubtedly causing the door hinge galling. Recommend
a 1/16 wall, steel plate with bolt hole drilled in center, be pop-
riveted over the elongated hole. Set the new plate so it holds the
ramp & jack firmly against the floor. Then fix the hinge pins ala
Steve & Joe's recommendation.
A good winter project,
JJ

Dave- Removing the rivets on the corner channel and reinstalling it
with new rivets is not a big deal. That only took a few minutes to
accomplish.

JJ, I think you are right on as to the root cause of this, I estimate
my trailer to have less
than 25k miles on it and the hole in the gate that secures the jack is
butchered from slapping around.

Almost always even after a short road trip I open my trailer top and
the gate
just falls to the ground from the securing pin bouncing loose.