SCOTT wrote:
One of the control arm brackets has rusted and broken off the rear axle
housing of my car. I can make up a new bracket, but then need to weld
it to the axle housing.. The axle runs inside of this in oil-from the
differential. Can I weld to it without starting a fire? Any advice


thanks,
Scott


You could probably do it without pulling the axle but my recommendation
would be to pull the axle first. Depending on what kind of car it's
usually not that difficult. that way you can drain the oil (change it
while your at it) and you will be able to see into the axle housing to
make sure nothing has happened.

Jim

"Jim Chandler" wrote in message
news:rKetk.954$w51.898@trnddc01...
SCOTT wrote:
One of the control arm brackets has rusted and broken off the rear axle
housing of my car. I can make up a new bracket, but then need to weld
it to the axle housing.. The axle runs inside of this in oil-from the
differential. Can I weld to it without starting a fire? Any advice


thanks,
Scott


You could probably do it without pulling the axle but my recommendation
would be to pull the axle first. Depending on what kind of car it's
usually not that difficult. that way you can drain the oil (change it
while your at it) and you will be able to see into the axle housing to
make sure nothing has happened.

Jim

I recommended pulling the axle as a way to allow wiping out the tube. The
gear oil is thick enough that a coating will remain in the tube and there is
still a chance of fire even if you drian the differential. Pulling the axle
is not that hard.

Carl

On Wed, 27 Aug 2008 18:33:28 -0400, with neither quill nor qualm,
"Carl Boyd" quickly quoth:


"Jim Chandler" wrote in message
news:rKetk.954$w51.898@trnddc01...
SCOTT wrote:
One of the control arm brackets has rusted and broken off the rear axle
housing of my car. I can make up a new bracket, but then need to weld
it to the axle housing.. The axle runs inside of this in oil-from the
differential. Can I weld to it without starting a fire? Any advice

You could probably do it without pulling the axle but my recommendation
would be to pull the axle first. Depending on what kind of car it's
usually not that difficult. that way you can drain the oil (change it
while your at it) and you will be able to see into the axle housing to
make sure nothing has happened.

I recommended pulling the axle as a way to allow wiping out the tube. The
gear oil is thick enough that a coating will remain in the tube and there is
still a chance of fire even if you drian the differential. Pulling the axle
is not that hard.

Or maybe just clean & unscrew the vent then charge the housing with
argon before welding. No fire could happen despite the presence of the
oil.

--
Smokey the Bear's rules for fire safety should apply to government:
Keep it small, keep it in a confined area, and keep an eye on it.
--John Stossel in _Myths, Lies, and Downright Stupidity_

Carl Boyd wrote:
"Jim Chandler" wrote in message
news:rKetk.954$w51.898@trnddc01...

SCOTT wrote:

One of the control arm brackets has rusted and broken off the rear axle
housing of my car. I can make up a new bracket, but then need to weld
it to the axle housing.. The axle runs inside of this in oil-from the
differential. Can I weld to it without starting a fire? Any advice


thanks,
Scott


You could probably do it without pulling the axle but my recommendation
would be to pull the axle first. Depending on what kind of car it's
usually not that difficult. that way you can drain the oil (change it
while your at it) and you will be able to see into the axle housing to
make sure nothing has happened.

Jim


I recommended pulling the axle as a way to allow wiping out the tube. The
gear oil is thick enough that a coating will remain in the tube and there is
still a chance of fire even if you drian the differential. Pulling the axle
is not that hard.

Carl




I agree Carl. One would hope that the welding won't build up that kind
of heat. Another consideration is VENTILATION. Even if it doesn't
catch fire, the Diff oil will SMOKE and you don't want to be breathing
that stuff. Make sure you are outdoors or have a very good fan pulling
fresh air in and exhausting the smokey crap. When I was racing
mini-stocks we welded the bearing to the flange so that if an axle
should break it wouldn't become a vaulting pole. I never had any
trouble with fire but there's always the chance.

Jim

I can't recommend it because of the potential hazard, but I had a Dana
70 dually rear from a rescue wagon that I installed in a 3/4 ton
pickup a different distance between the springs. I ground off the old
welds holding the original spring perches to the axle tubes, and MIG
welded new perches on, without opening the rear or pulling the axles.
I just let the axle tubes cool a bit between passes with the MIG. I
guess there was not enough air in the housing to sustain much of a
fire, or the oil never lit off. Each of the four weld beads was about
3-4 inches long. In any case I've put 200K miles on the rear since
without issue.