On 07/10/2018 15:42, Chris Green wrote:
One of the UJT yokes on our Kubota tractor has failed, one of the
'arms' is broken so no longer retains the needle roller bearing.

Is there any sane way of repairing this as replacements seem nearly
impossible to find. It's a bit of a strange design as the yoke goes
direct onto a flanged shaft (i.e. it has an internal spline) so
finding a non-Kubota replacement is unlikely. However if anyone can
recommend suppliers of (small) UJTs with splined connections I'd be
interested.

Possibly cast iron?

When you say broken, do you mean a brittle fracture or something else?

Photo?

Cast iron can certainly be TIG welded with the right rod and some skill.
I'm not sure if it can be silver soldered. Maybe SG can be, not sure
about grey. Google is ambiguous.

If it were mine (and not having TIG) I'd probably try silver soldering.
Obviously, you might need to bore out and sleeve the bearing housing
afterwards, or perhaps see if a bigger bearing can be fitted. Failing
that, might it be possible to cut off the splines and graft them on to
something else?