Diff housing welding

[merc-blue]

Guys,
Im wondering if you can weld onto a diff housing to move mounting points? if so do you need to preheat the WHOLE housing to prevent the cast from cracking? or can you just mig it on (or would arc be better with the heavy cast-flat steel)
Cheers
Rohan

[oldcorollas]

the axle tubes of the housing are usually not cast, they are usually tube steel, so it is ok to weld to them. you may need to pre-heat enough to get good penetration tho (but i don't know how much or if it is needed)

mig is cleaner, and the sections are not that thick, so should be ok.... as long as the welder and the wire is up to the task... practice with similar thickness metal (2-3mm thick?) and get the settings right first...

not sure about bending of the tube after welding either....

[Ben Wilson]

Any decent welder should be able to weld to a diff tube without a problem.

[merc-blue]

OK great, i wasnt sure what the wall thickness/material of the diffs were, i should be able to do this in at tafe
our big migs have done 20mm thick stuff i might pre heat it abit, the welding boss will be able to guide me through it/do it for me, i dont have much experince beyond mig/tig/arc roll cages and flat steel and alloy

[brett_celicacoupe]

i welded up my diff with a stick welder...... try not to accumulate too much heat in one spot as the tube may distort a little. i dont know how much heat will cause this but i did a series of 15mm welds. allowing some cooling between each run.

[Big T]

I understood that this should only be done with a proper diff jig so all the mounting points are actually correct. I had mine done at a diff shop since i have zero welding skills but his price included "straightening of the housing" so i guess they do check them afterwards for warpage.

Eddie.

[merc-blue]

hmm i might weld it up becasue getting them spot on shouldnt be bad but i might get a diff place to check its straight, i know some people who wil do it quickly after hours cheaply

[brett_celicacoupe]

just make up a jig.



here is mine. that was when i was making the jig fiit the T series diff.



sorry for the large pic

[cri_ag]

there is no need to pre-heat (or not in my experience) and you will get a decent weld with good penetration using a >200a welder provided you know how to weld! the axle tubes are not ridiculously thick any way. if your mounts are say 3mm steel then the norm would be a 3mm-4mm weld leg length.

[allencr]

prevent the cast from cracking? ...heavy cast-flat steel
& i dont have much experince beyond... flat steel

What cast???


That's exactly what this is, except that the flat steel has been stamped into a 'U' & put together with some steel castings(or forgings) on each end, and a large steel ring in the center.