Welding rear diff Q's

[Area54]

From another member, I'm after SERIOUS tech on the process of welding up open diffs, both banjo and salisbury style housings. Apart from the common sense things like pull down processes which will vary of course, and the need for cleanliness with slag/spatter etc.

Answers are needed for the following:

1. Which rod/filler wire works the best. More info on this the better, as not everyone has a $12000 Mig at home.

2. Where is the best place to weld - side gears to pinion gears, outer edge of the gears, between the meshing teeth (problems with case hardening on the teeth?)

Any other relevant information is also good. A search did not yield much specific info on this subject, so tradies, speak up!

[POS]

I don't know what rod to use, however i do know where to weld!

I have welded a couple now and i havn't had one let go!

I weld the Star gears together where the teeth mesh, Really lay it in there.

I then cut a small plate that slots in between the star gears and weld that into place!

The main thing i do is weld a little at a time and let it cool, I try not to get it to hot!

Like i said I usually destroy the Ring and pinion and the welds are still fine.

I think there may be one of my old centres out at sams that has been welded, though they did have a clean up so it may be gone. I will have a look tomorrow for you!

[Guy]

I welded mine .. I simply built up the weld (using and arc with a "normal" blue cig rod) on a pretty low amperage and weled the side gear to the casing .. This was for a Suzuki diff .. I basically kept on going until the entire area between the gear and casing was filled with metal ..
I am not sure of the "quality" of the weld .. but due to sheer physical mass it has to hold together

[zookjedi]

low hydrogen 16tc rods with a stick welder

[ODD BALL]

I don't know what rod to use, however i do know where to weld!

I have welded a couple now and i havn't had one let go!

I weld the Star gears together where the teeth mesh, Really lay it in there.

I then cut a small plate that slots in between the star gears and weld that into place!

The main thing i do is weld a little at a time and let it cool, I try not to get it to hot!

Like i said I usually destroy the Ring and pinion and the welds are still fine.

I think there may be one of my old centres out at sams that has been welded, though they did have a clean up so it may be gone. I will have a look tomorrow for you!

He had it nailed! The only other thing you could do is make sure you keep the slag from bolding to the ring gear while you weld. Good luck.

[V8Patrol]

low hydrogen 16tc rods with a stick welder

Yep definately WIA rods ....16TC. and use a DC welder if you can find one, if not peening it as you go will help considerably.

weld the spidergears to each other and for added strength to the housing aswell.

To "limit" the problems with spatter/slag.... spray the areas you DONT want affected with "sprayon cooking oil", the cheaper the better.... IE Black n Gold Canola oil !....works a treat and is dirt cheap !!!

If you are using a mig welder...
Strip the diff centre down as far as possiable,
apply heat to the unit with an oxy/accetelene ( called pre heating)
weld
reheat again ( this "normalises" the unit as a whole)
slowly decrease the heating so the unit cools down gradually.

Alternativly...
If possible wack it in a preheated oven (250 degrees) for a couple of hours.
pull it out n weld it.
back in the oven for 1/2 an hour then decrease the temp back to 200
1/2 an hour later decrease the temp back to 150 and so on....
This process works really well on castiron too.... many a vice has been repaired in our oven !!!