Hi, my mechanic has repaired a broken steering box bracket by welding
This has been done twice and now it is breaking again. What could be
the repeated breaking?
By the way, the car drives so much smoother with the steering box able
move around. I think the box is moving even with the bracket not
sticking so the alignment is off. Then with the bracket broken I don't
it is sticking any more, hence the smooth ride. So what else could be
broken, maybe the frame it bolts onto? Does this make any sense?
On 12 Jul, 16:50, email@example.com wrote:
That's correct it has been in a front end collision and some of the
frame was welded before I bought the car. I presume the frame is not
rigid anymore causing stress on the bracket, right? That sounds like a
difficult frame repair, considering the car has a 3 or 4 more years of
If that is correct then I think a loose steering box is able to float
to compensate for frame movement, but that good effect will end up
with another broken bracket. Unfortunately for my mechanic he
guarantees his work so he has to keep repairing the bracket, not a
happy situation for him. What would you advise him to do? Is it
possible to reinforce the frame for a reasonable effort?
The way I experience the car, it is a straight frame because the tire
wear is normal. There just seems to be something moving. If it is a
broken frame it might be right to be concerned about the safety. I
don't know what would happen if the frame suddenly came apart, I
wouldn't want to be travelling at high speed. Maybe it could be welded
without if it the break could be seen.
On Fri, 13 Jul 2007 10:53:03 -0700, firstname.lastname@example.org wrote:
Welding actually weakens the area around the weld. That's why the Liberty Ships
nearly always broke in half.
It might have to be plated but I still say it's dangerous. Get it down to a
chassis/body shop with a Laser aligning jig or a BMW body shop to be checked.
IT'S NOT SAFE
Dave - I didn't say that. there is welding and "WELDING" one is done by divi
Jones the work experience school leaver and the other is done by educated
professionals with years of experience.
It only need a bit of oxygen to reach the molten metal and the weld is flawed.
GAS, MIG & ARC have always been the favorites of crash body shops and gas is
the main culprit of porous welds with ARC coming a very close second. MIG is
generally better in the hands of a skilled operator but only if there is enough
gas pressure and flow rate.
BTW 99.9% of all airplanes are riveted and they are pretty strong they only seem
to break up when they hit the ground at speeds over 300 MPH as your car would -
don't know many ships that go that fast except space-ships.
On 13 Jul, 16:55, email@example.com wrote:
What would actually happen if the frame came apart? Would the front
tires suddenly splay outwards bringing the chassis down to the road,
or would the chassis hold it together for a while where bolted to the
Negative. They broke because of the relationship between the length of the
ship and the length of the waves at sea. It caused a harmonic motion that
weakened the ship at the midship (middle) by lifting the bow (front) out of
the water and slamming it down as the wave passed. A period of time doing
this caused the metal to fatigue. That's why the Liberty ships were
overhauled by adding a steel belt at the midships area. Welding had ZERO to
do with it. I saw the History channel episode on Liberty ships, maybe you
should, too. This is an excellent thread on mis-information. And if welding
caused weaked areas, why is it so prolific throughout metal construction of
any kind? Yeah, I thought so. Moving on...
Bill in Omaha
Ok Bill - wrong example but the QE2 and many other ships of equal size didn't.
BTW I did see that prog last year and remember the reinforcement belt.
The truth still stands that the heat generated when welding can and does weaken
the surrounding metal. Generally if you look at a broken "welded" joint you
will invariably see the weld intact and the metal around it has broken showing
Obviously we must have watched different episodes.
Wave lengths vary at sea as does the angle of incidence of the ship, so
inevitably every ship will experience waves that will resonate with the ship
at some time in their lives.
The real reason Liberty ships sank is as follows: -
The steel was cheap and of poor quality, but the particular problem was
that the relatively high carbon content meant that the steel became brittle
at low temperatures, such as those experienced in the north Atlantic in
2. Welded without stress relief
An all welded ship was a new idea, and it was not realised that once
started a crack could propagate through the entire structure. In particular
the deck hatches were rectangular with right angle corners and this provided
a point of high stress for cracks to start from.
3. Amateur Welding (well not quite)
Workers building the ships were relatively inexperienced (most
experienced ship builders had been drafted) in ship building in general and
welding in particular. Tight schedules (like building a ship in three days)
meant that there was little quality assurance and welds were often weak or
defective and / or liable to corrosion. Poor technique also weakened the
steel near the weld.
4. Poor loading
In the fog of war the ships were simply loaded willy nilly, resulting in
increased stresses in the hull.
The net result was that cracks would start in the corners of the hatches and
propagate right around the hull and the ship would split in two. The are
plenty of pictures of half liberty ships, and one allegedly split
immediately after launch.
That said, after relatively light remedial work (around the hatches) many
liberty ships spent decades plying in the tropics (as well as vulnerability
to cold they usually also lacked heating for the crew), and IIRC the last
one only retired in the 90's.
Early Comet aeroplanes also suffered in this way.
Or was it a Lockheed L-1011 that had the cargo door failure?
...but I think the incident I am referring to was a DC-10.
Its happened over France or Germany. The cargo door wasn't
closed properly by ground crew. The cargo door blew open
at high altitude. The differential pressure between
the cargo and passenger compartments buckled the passenger
deck. Unfortunately all the control cables ran underneath the
passenger deck, causing the crash.
Does a 535 have a frame? or is it unibody
Just the facts: The aircraft suffered an explosive decompression while
climbing through 11,000 feet after takeoff from Paris Orly
Airport. Due to a design flaw in the locking mechanism of the
cargo door, a ground crew member was able to force the
locking arm into position, while the door was not, in reality,
locked. Climbing into thinner air, the door was unable to
remain closed without the lock, and it burst open. The
outrush of air caused the cabin floor to collapse and
severe all control cables, leading to a loss of control
by the flight crew.
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