I wouldn't worry much about the seals.. there are lots of replacement
styles, or even a greased leather washer (riding on a polished shaft) held
by a sheetmetal retainer will work effectively at keeping dirt out.
This is assuming that the lube is gear lube, not a hydro transmission (you
said 1964 machine).
You may still need torch heat to pull the hub, since the hub may not have
been removed for decades.
The primary disadvantage is needing to use a handheld drill, which can
attribute a lot to rapid drill point failure.. using a steady position and
forceful feed pressure are going to be to your advantage. The drum should be
secured so it can't rotate.
If you can clamp a bar or other steady support nearby, it would likely help
keep the proper approach angle and position.
In awkward positions and using a handheld drill, it can be worthwhile to
take some time to fabricate a mechanism to apply more feed force and steady
positioning using a lever to increase the feed force while offering a very
steady feed direction.
In this situation, even a Cole drill wouldn't be a simple solution due to
the drum size and the angle of the screw, but maybe something as simple as a
section of chain and a lever pressing on the back of the drill motor would
be appropriate.
The masonry drill suggestion could be a good solution, and for as cheap as
they are, grinding them to suit your needs should make them even more
effective for your needs.
I'd suggest using a proper steel cutting lubricant, not just anything that's
handy and slow RPM.
With a steady and forceful feed mechanism, using a pin and high RPM (no
lubricant), friction may generate enough heat in the screw to soften it, but
this method would likely be more appropriate for a workpiece on a drill
press.
An air chisel used as a hammer, hitting on (a hex or mating) driver, with
the hub supported by a steady hard backup like a jack stand on a cement
floor (not a block of wood on soil) may be enough to work the screw loose
while saturated with penetrant of ATF or miracle product.
Hex wrench material and some hardened drivers are likely to shatter, so, the
use of some fuel hose or other protective shroud would/should prevent shards
of metal from shooting out and injuring the operator.. and uncommon sense
should dictate the use of all the personal protection/safety devices/apparel
required for safe practices.
With a series of impacts the screw may dig into the key a bit more,
relieving the holding grip in the key slot, and a couple/few thousanths inch
of relief would be adequate to loosen the grip of ordinary square keystock,
so a stable puller could pull the hub/drum off.
Having the part removed from the axle will give you more options for dealing
with the screw if it hasn't loosened to the point of just winding it out (or
inward into the hole).
An annular cutter just larger than the screw diameter should effectively cut
away the softer iron without dealing with the hardened screw.
It looks as though you'd need to prepare a flat surface *like a counterbore
around the screw hole) for the cutter to start on, with a die grinder
(Dremel/Foredom etc).
I don't have a source handy, but these tiny holesaw-type cutters are
available for cutting thru spot welds (although not particularly deep
capacity) and other purposes.
Woodworkers use similar centerless cutters for cutting plugs and dowels, so
cutting cast iron with a quality cutting lubricant and slow speed may
accomplish the desired results.
--
WB
..........
wrote in message
...
Here is what I'm working on.
http://s1123.photobucket.com/albums/...t=IMG_2610.jpg
1964 garden tractor. The wheel hub must come off before the brake
linkage can be removed before the transmission can be removed, etc.
The hub is cast about 3/8 thick. The brake drum is bolted to the back
of it so there is no place to hook a puller or anything like a bearing
separater. The lug bolt holes are the only pulling points (5 on
4.5"). Problem is the 5/16 set screw.
I've tried drilling them out with what I thought were pretty good
bits. I'm barely knocking the rust off. They are hard. I've used an
allen impact driver to no avail. (good part is they don't strip out)
There is enough meat to redrill and tap to larger size.
I can apply limited heat but don't want to be looking for nonexistant
axle seals.
Once the set screw problem is solved, I can (reluctantly) drill and
tap pulling holes closer to the 1" axle.
This photo looks dry but it has been flooded with JB Blaster for two
months. An additional consideration is this is one of only two
surviving. Suggestions?