Auto Transmission Cases

[JOHN1]

Have always had a hard time repairing auto transmission case.

Is it due to a "magnesium content"?
Is is better to use tig or use a spool gun?


Thanks
John1 (Jweld)

[arcdawg]

first off anything that is under a car is going to be really dirty and aluminum is porus? so clean the snot out of it...and dont forget to preheat and or bevel you joint..... or at least it seems to be.... then cast is a p.i.t.a to weld but i would use tig and see if you can come across some al. tig junk rod .......where its a bunch of alloys that are all thrown in togheter ...... **** i could be totally wrong !

dawg

[aametalmaster]

John, I have welded quite a few auto trans cases with the first with a stick welder. It was ok. Then I got a MM spoolgun it's a lot better. I never tried tig. One thing you have to do is clean it super good. Grinder, wire brush, parts cleaner, ect. Then heat up the area with a torch to remove all traces of atf fluid. Cook it out real good. It should weld ok for you...Bob

[JOHN1]

Thanks for the replies.
Don't have a spool gun but plan to get one to go with my MM Vintage.
Thanks Again

[Canuck]

I would TIG weld it for a few reasons. The first being more control over your parameters and the heat in to the piece, secondly you have time to think and can go slow enough to make sure you get fusion because with AL. MIG you have to move fast and turning corners and following lines is much harder. And lastly on a smaller scall an alumimum MIG weld has more surface porosity than a TIG weld which might cause it to crack again.
Hope this help.