Jarrid Gross (Yorba Linda, CA) wrote:
>
> Alpiners,
>
> Being niether a metalurgist nor a welder, could the brass shifter
> fork in an alpine trans be welded, then re-machined for re-use
> in same transmision?
>
> Brazing?
> Warpage?
> Strength?
>
> My SV all-sync trans pops out of third, and all evidence points
> to a worn third fourth shifting fork.
>
> It was sort of sloppy, but it didnt look too bad to me when I went
> through it, but under high RPM decel, it sometimes pops out.
>
> Any idears?
>
> Jarrid
Jarrid
The advice you are getting sounds good but could use a little
amplification (code word for more than you really want to know!)
In any welding job, you always try to match the filler parent metal as
closely as you can. In this case, it's going to be difficult but I
suspect the alloy you want is a phospor-tin with with some aluminum and
beryllium added for additional wear resistance. I would go to your local
welding supply store and ask if they have any bare bronze rod and flux
suitable building up gear teeth. (The reason for not using the
flux-coated rod is that this flux contains much that is used for
removing mill-scale etc. which is not necessary in this job. Also, flux
intended for copper based alloys will flow at a lower temperature)
I would advise using a degreaser (and washing it off - toxic when
heated!) then cleaning mechanically. Supporting your work is all
important to prevent sagging (Firebrick or carbon block) and preheating
the whole thing will help prevent warping.
Temperature is important, since you won't have the stability of welding
on steel and you will probably need to use a slightly larger tip than
you would on steel that was the same thickness. Use a slightly oxidizing
flame and forehand (torch pointed in same direction
you are welding in) technique.
When working, keep the torch about 1/4 in. off the metal and pull
back rather than away if you get too much heat. If you get any popping
or see any white deposits along the weld, you're too hot and the zinc
is boiling out of the alloy).
Also, to prevent warping, it would be advisable to work back and
front (top and bottom) of the area you are building up equally.
It's much easier than it sounds above. so go for it, and I hope this
helps!
Ron Tebo - Series I - B9000627
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