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

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

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.

On Dec 19, 7:38*am, Steve Koerner wrote:
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.

Keep in mind that aluminum and bronze aren't very compatible from a
corrosion standpoint. The aluminum is going to be sacrificial to the
bronze. Since you've got lots of aluminum and only a little bronze it
isn't horrible, but a stainless bushing is a better choice if you're
going to stay with the aluminum pins.

Cheers,
Craig

On Dec 19, 6:51*am, Dave Nadler wrote:
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_...orn_hinge_clos...
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....html?dsId=217....

Dave, you already have lots of good advice but here's another idea.
http://www.popsci.com/diy/gallery/20...-plans?image=4

Metal filled epoxy like this is just as strong as aluminum. It could
be used inside the frame tubes to re-size the holes. If you coated
the new pins with mold release compound and clamped the door in
perfect alignment while the epoxy set up, you'd have a tight, rattle
free fit. The fix would probably last as long as the rest of the
trailer. If it didn't, it's easy to repeat the repair.

Can't use that, product doesn't even have
the word "Miracle" in the name.
Might work for winch bearings though.

I'm going to use bushings in the corner channels and
a steel (ideally stainless) hinge pin. The pin won't
wear out, and if the bushings wear they're just a
few minutes to replace.

Anybody up for making replacement pin kits ?
Here's a rough (I know, very rough) sketch:
http://www.nadler.com/Antares/CobraRearDoorHinge_4.pdf

Joe ? Steve ?

Alternatively, can anyone recommend a favorite
internet machine shop ?

Happy Holidays,
Best Regards, Dave "YO electric"

PS: Wear on pins is only on one side: door moving
downwards when closed, or upwards when open. I think
most likely I've caused this by cranking trailer nose
up against door opened on ground to steady rear of
trailer(instead of using the cranky rear jack stands)...