Cobra top hinge plate bolt failure

On May 22, 3:17*pm, Ken K wrote:
Does opening the top allow you to do individual bolt replacement with
no additional clamping? i.e the struts are fully extended and the
'lift' vector is almost vertical.

KK







3) Do NOT remove these bolts without clamping the
trailer top down and restrained from moving
forward. If you undo the bolts without restraining
the top, even on just one side, even just one bolt,
the gas strut will deliver you a nasty surprise
(as happened to me on the highway to Hobbs).
CAREFUL !

5) I'm designing a clamp to safely hold the top
during replacement of the hinge and bolts...

What Dave said!

However the clamp does not need to be anything special. I changed my
bolts yesterday using a 2.5 inch C clamp that was quite a bit less
substantial than the one shown in Steve (GW)'s write up.

Trust us - It's far easier to clamp the parts while they are in
alignment than to try to get them back into alignment if you try
without clamping!

Andy (GY)

I have just checked my UK based 15M 1999 Cobra trailer (glass sandwich
top). This has only been towed on reasonably smooth roads (excluding the
odd field) and only very occasionally opened in strong winds .
There is some slight compression to the glass shell at the outer mounting
holes on each handle. When checking the bolt tightness I noticed that the
nuts on the outside mounting bolts (inside the trailer on the hinge plate)
are both not square to the hinge plate as though they were fitted at a
slight angle. (approx 1mm gap is at the top of the bolt ) .
I have vague recollections they had always been like this and assumed at
the time that this was because it was not possible to square everything up
when mounting the bolts at the factory. However, I now wonder if the lid
has moved up slightly inclining the outer bolts.
I “gently” tightened all the bolts a couple of turns (using a small 6”
spanner to limit torque) so it would appear that they were working loose.
I was in a hurry when I did this and seem to remember the extra torque
reduced the gap at the top of the inclined bolts.
Few of questions
- Has anyone else noticed if any of their hinge mounting bolts were at a
slight angle when delivered ?
- Does anyone have a “method” of judging how tight to do these bolts
should be. I am loath to snap them or do more compression damage before I
get round to re-enforcing the handle area and fitting stronger bolts.
- Regarding clamping the hinge to the aluminium cross member. When the
bolts are removed what stops the aluminium cross member from ripping out
of the top shell. I assume it is glued in ?

On May 23, 7:48*am, Ian Reekie wrote:
When the bolts are removed what stops the aluminium cross member from ripping out
of the top shell. I assume it is glued in ?

It is riveted to the top side rails. However one US owner has found
all rivets sheared. All mine seem ok.

In any event you should only change one bolt at a time!

Andy

Interesting, I took a couple of pictures of the hinge and they seem to show
no structural connection from the side rails to my cross member ?
I am flying tomorrow so I will examine this further, but I wonder if they
varied the construction. Many of my aluminium support brackets are glued
to the shell with what looks like a black polyurethane glue, similar to
that used in the car industry to glue panels. I assumed this was the case
for this cross member.
I agree that It would be ideal to change one bolt at a time, but I was
thinking of implement Steve Koerners mod which I believe would require you
to remove both bolts to get the 1/4" spacer under the handle ?


It is riveted to the top side rails. However one US owner has found
all rivets sheared. All mine seem ok.

In any event you should only change one bolt at a time!

Andy

Interesting, I took a couple of pictures of the hinge and they seem to show
no structural connection from the side rails to my cross member ?
I am flying tomorrow so I will examine this further, but I wonder if they
varied the construction. Many of my aluminium support brackets are glued
to the shell with what looks like a black polyurethane glue, similar to
that used in the car industry to glue panels. I assumed this was the case
for this cross member.
I agree that It would be ideal to change one bolt at a time, but I was
thinking of implement Steve Koerners mod which I believe would require you
to remove both bolts to get the 1/4" spacer under the handle ?


It is riveted to the top side rails. However one US owner has found
all rivets sheared. All mine seem ok.

In any event you should only change one bolt at a time!

Andy

On May 23, 10:39*am, Ian Reekie wrote:
Interesting, I took a couple of pictures of the hinge and they seem to show
no structural connection from the side rails to my cross member ?
I am flying tomorrow so I will examine this further, but I wonder if they
varied the construction. *Many of my aluminium support brackets are glued
to the shell with what looks like a black polyurethane glue, similar to
that used in the car industry to glue panels. *I assumed this was the case
for this cross member.
I agree that It would be ideal to change one bolt at a time, but I was
thinking of implement Steve Koerners mod which I believe would require you
to remove both bolts to get the 1/4" spacer under the handle ?





It is riveted to the top side rails. However one US owner has found
all rivets sheared. All mine seem ok.

In any event you should only change one bolt at a time!

Andy- Hide quoted text -

- Show quoted text -

Mine also has the black glue. Email me and I'll send you a photo that
shows the rivet locations.

It should be easy to change one bolt at a time even when introducing
the new plate. Just leave the first new bolt slightly loose so the
plate can be rotated into alignment after the second bolt is removed.

Even if you decide to remove the handle to work on it you can still
put bolts in place to maintain the alignment.

Having dealt with this issue once I would go to great length to ensure
that both bolts were never removed at the same time.

If you want all the bolts out then raising the top, disconnecting the
gas struts, and then doing all the hinge work with the top closed may
be the way to go. You'll need several strong friends or an overhead
hoist though.

Andy