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?

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?

First time I heard of PB failing. If you do get it off, give us a review of
what you think had it stuck so hard.

Steve

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?

My first choice would be heating with a TIG torch.
Concentrate on
the set screw and get it hot, red hot if you can.
There is enough
mass of iron there to save the seal if you stay on
the screw. After
it cools to about 300 to 400 deg apply 50/50 atf
and acetone. Make
no attempt to turn it till it completely cools
off! When the screw is
heated it will try to expand but it cannot and
when it cools it will
shrink to allow turning. HTH....
If you don't have TIG then try an oxy acet gas
welding torch,
single flame. Stay on the screw.... oh, I already
said that....
phil k.

On Sat, 24 Sep 2011 14:47:44 -0400, "Phil Kangas"
wrote:


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?

My first choice would be heating with a TIG torch.
Concentrate on
the set screw and get it hot, red hot if you can.
There is enough
mass of iron there to save the seal if you stay on
the screw. After
it cools to about 300 to 400 deg apply 50/50 atf
and acetone. Make
no attempt to turn it till it completely cools
off! When the screw is
heated it will try to expand but it cannot and
when it cools it will
shrink to allow turning. HTH....
If you don't have TIG then try an oxy acet gas
welding torch,
single flame. Stay on the screw.... oh, I already
said that....
phil k.


I have a couple of O/A torches. Do you think heating the screw will
change the hardness enough to be able to drill it?

It is in at an angle so only one edge is contacting the key. If I can
drill it, I think that thin edge might bend or break off when pulling
the hub off.

wrote in message
...
On Sat, 24 Sep 2011 14:47:44 -0400, "Phil
Kangas"
wrote:


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?

My first choice would be heating with a TIG
torch.
Concentrate on
the set screw and get it hot, red hot if you
can.
There is enough
mass of iron there to save the seal if you stay
on
the screw. After
it cools to about 300 to 400 deg apply 50/50 atf
and acetone. Make
no attempt to turn it till it completely cools
off! When the screw is
heated it will try to expand but it cannot and
when it cools it will
shrink to allow turning. HTH....
If you don't have TIG then try an oxy acet gas
welding torch,
single flame. Stay on the screw.... oh, I
already
said that....
phil k.


I have a couple of O/A torches. Do you think
heating the screw will
change the hardness enough to be able to drill
it?

It is in at an angle so only one edge is
contacting the key. If I can
drill it, I think that thin edge might bend or
break off when pulling
the hub off.

Heat will soften it. Try a smaller drill first,
stepping up in size.
It may be possible that the screw is in a shallow
hole in the key.
That would secure the key from working out in
service. Something
to consider anyway.
phil k.

On Sat, 24 Sep 2011 21:21:26 -0400, "Phil Kangas"
wrote:


wrote in message
.. .
On Sat, 24 Sep 2011 14:47:44 -0400, "Phil
Kangas"
wrote:


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?

My first choice would be heating with a TIG
torch.
Concentrate on
the set screw and get it hot, red hot if you
can.
There is enough
mass of iron there to save the seal if you stay
on
the screw. After
it cools to about 300 to 400 deg apply 50/50 atf
and acetone. Make
no attempt to turn it till it completely cools
off! When the screw is
heated it will try to expand but it cannot and
when it cools it will
shrink to allow turning. HTH....
If you don't have TIG then try an oxy acet gas
welding torch,
single flame. Stay on the screw.... oh, I
already
said that....
phil k.


I have a couple of O/A torches. Do you think
heating the screw will
change the hardness enough to be able to drill
it?

It is in at an angle so only one edge is
contacting the key. If I can
drill it, I think that thin edge might bend or
break off when pulling
the hub off.

Heat will soften it. Try a smaller drill first,
stepping up in size.
It may be possible that the screw is in a shallow
hole in the key.
That would secure the key from working out in
service. Something
to consider anyway.
phil k.


Many set screws actually harden with heating - from my experience

On 9/24/2011 6:42 PM, wrote:
On Sat, 24 Sep 2011 21:21:26 -0400, "Phil Kangas"
wrote:


wrote in message
...
On Sat, 24 Sep 2011 14:47:44 -0400, "Phil
Kangas"
wrote:


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?

My first choice would be heating with a TIG
torch.
Concentrate on
the set screw and get it hot, red hot if you
can.
There is enough
mass of iron there to save the seal if you stay
on
the screw. After
it cools to about 300 to 400 deg apply 50/50 atf
and acetone. Make
no attempt to turn it till it completely cools
off! When the screw is
heated it will try to expand but it cannot and
when it cools it will
shrink to allow turning. HTH....
If you don't have TIG then try an oxy acet gas
welding torch,
single flame. Stay on the screw.... oh, I
already
said that....
phil k.


I have a couple of O/A torches. Do you think
heating the screw will
change the hardness enough to be able to drill
it?

It is in at an angle so only one edge is
contacting the key. If I can
drill it, I think that thin edge might bend or
break off when pulling
the hub off.

Heat will soften it. Try a smaller drill first,
stepping up in size.
It may be possible that the screw is in a shallow
hole in the key.
That would secure the key from working out in
service. Something
to consider anyway.
phil k.


Many set screws actually harden with heating - from my experience

if it were me, I'd use Kroil for a bunch of days, then I'd heat the hub
and when it is hot (but not glowing), I'd put a hex key in the set screw
and loosen it (or if it's not a hex key, use whatever fits it) - the
heat will expand the hub and tend to soften/break down the rust. If
that doesn't work, let it cool and repeat with more kroil, some time,
and try again

wrote in message
...
snip--
Many set screws actually harden with heating - from my experience

I'm having more than a little trouble believing that. I'm not aware of any
set screws being made from precipitation hardening steels, although I do
suppose they could be. Beyond that, the only way the screw would be harder
is if it was heated rapidly, heating only the screw, so the surrounding
material behaved as a heat sink and quenched the material while the carbon
was still converted. Sort of like a chilled iron casting. I'm having a
problem with the idea that that happens, especially when heating by torch.

I'd suggest that a fast heating to a dull red heat would anneal the screw.
Once annealed, whether it backs out or not (it may, for the heat will have
also disrupted the rust that has formed), it will be dead simple to drill
out. Drilling to the minor diameter of the screw should result in a clean
hole with threads entrapped, like half a heli-coil.

Harold

On Sep 24, 10:48*am, wrote:

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

I would not be considering heat since it is pretty easy to get to the
set screw as as you say seals could make for an interesting search.

If you don't have a small carbide drill, then what about a small
masonry drill with carbide tips? Check the local hardware store as
ours has them down to 1/8" for drilling mirrors and tiles etc. Slow
and steady and wd40 as cutting fluid.

Dave

I'm just clutching straws. But.... heat on the setscrew, and
then use left handed drill bit from HF.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


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?

"Stormin Mormon" wrote in message
...
I'm just clutching straws. But.... heat on the setscrew, and
then use left handed drill bit from HF.

--
That's pretty clever, coming from a mormon! :-)

Harold

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?

On 9/25/2011 7:53 AM, Wild_Bill wrote:
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.



If there is any way to get the correct bit in a hand operated impact
tool, it would allow a quick tighten and loosen movement on the set
screw. A tool like this:
http://www.lislecorp.com/divisions/p...s/?product=151

I know you can get a 3/8 socket drive Allen bit which can be driven by
the tool.

On Sun, 25 Sep 2011 09:32:18 -0500, DanG wrote:





If there is any way to get the correct bit in a hand operated impact
tool, it would allow a quick tighten and loosen movement on the set
screw. A tool like this:
http://www.lislecorp.com/divisions/p...s/?product=151

I know you can get a 3/8 socket drive Allen bit which can be driven by
the tool.

That is what I've been using. Mine is a little more heavy duty; 1/2"
drive. Of course, I have to use a 1/2 to 3/8 reducer so I may be
losing some torque in the extra joint. I'm twisting the barrel in the
pre-loaded direction. The allen size is 5/32 so I can't get too heavy
handed.

I went out earlier and heated them; waited until they cooled and
smacked them again. No joy. They are now soaking in PB Blaster again.

If they are not loosened by towmorrow, I'll start drilling again.

Thanks for all the suggestions.

If you are using a handheld drill and not getting any chips out, your next
best bet would be to (borrow one if you don't have one) use a benchtop drill
press set up on blocks, at the correct angle so the quill downfeed would be
constant and steady.

My box-store Ryobi ~10" benchtop could be set up in place, and definitely
has enough power to drill those screws out.

Those little 5-speed $50 drill presses probably aren't any better than (or
even as good as) a decent hand drill. A friend suggested I could use his
5-speed recently while doing some fabricating at his place, and it was
essentially powerless, with a sharp 3/16" drill in mild steel.

A quality cobalt drill or masonry carbide (and a good cutting lubricant)
should cut the screws with a steady, constant feed, which is often difficult
to do with a handheld drill.

--
WB
..........


wrote in message
...

That is what I've been using. Mine is a little more heavy duty; 1/2"
drive. Of course, I have to use a 1/2 to 3/8 reducer so I may be
losing some torque in the extra joint. I'm twisting the barrel in the
pre-loaded direction. The allen size is 5/32 so I can't get too heavy
handed.

I went out earlier and heated them; waited until they cooled and
smacked them again. No joy. They are now soaking in PB Blaster again.

If they are not loosened by towmorrow, I'll start drilling again.

Thanks for all the suggestions.

On Thu, 29 Sep 2011 08:39:54 -0400, "Wild_Bill"
wrote:

If you are using a handheld drill and not getting any chips out, your next
best bet would be to (borrow one if you don't have one) use a benchtop drill
press set up on blocks, at the correct angle so the quill downfeed would be
constant and steady.

My box-store Ryobi ~10" benchtop could be set up in place, and definitely
has enough power to drill those screws out.

Those little 5-speed $50 drill presses probably aren't any better than (or
even as good as) a decent hand drill. A friend suggested I could use his
5-speed recently while doing some fabricating at his place, and it was
essentially powerless, with a sharp 3/16" drill in mild steel.

A quality cobalt drill or masonry carbide (and a good cutting lubricant)
should cut the screws with a steady, constant feed, which is often difficult
to do with a handheld drill
I have a big drill press but I don't see any way this is happening.
the "piece" I'm working on is 4' long, the axle is 3' wide. The whole
assembly weighs over 200#. The set screw is at about a 45 degree
angle.

I'm using a 1/2" drill at slow speed. I'm able to really lean into it
so I think the pressure is there, at least as much as should be put on
1/8 and 3/16 bits.

Here's my strong vote for "heat and quench 3 times".
I am sure you got the right idea from all the previous posts on this
subject, but you need an OA torch with a really small tip, say a #1, in
order to heat just the set screw. Get it glowing and have a squirt bottle
of water handy. Once the set screw is glowing, squirt water on it until it
is cool to the touch. Do this 3 times. Then, gently remove the set screw.
A year or so ago I was faced with a couple dozen different kinds of
stuck/broken off bolts in an Onan genset and I asked for help everyplace I
could think of. The above was one of the suggestions I received late in the
game and hadn't tried it myself until a few weeks ago. A guy brought in a
front wheel drive car hub for bearing replacement. It had a sheet metal
guard held on by 3 10-32 (or metric equivalent) screws that had been there
since 1995. None of my normal stuff worked so I tried the above. It worked
3 out of 3 times. I am a convert.
But, you have to be able to really focus the heat, I think.
Note: one of the reasons you can heat the screw alone is that the
rust/corrosion between the screw and the hub acts as an insulator so the
screw heats faster than the hub (the hub having more mass). But, if you use
too broad a flame, or a torch with a much lower flame temperature(think
hardware store propane torch) the set screw will take longer to get glowing
and the hub will be closer behind in temperature, so the set screw won't be
crushing the rust as much.

See:
http://www.spaco.org/MachineShop/StuckFasteners.html
if you are interested in a range of solutions to this kind of problem.
Long time lurkers:
I haven't added to this page since Jan 23, 2010, when I posted its existence
here.

Pete Stanaitis
---------------

On Sat, 24 Sep 2011 12:48:04 -0500, wrote:

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?

Update.
After heating, more PB, let it cool, still won't budge. 1/4" masonry
bit took off just a little bit. Used a 3/16 punch in the socket a few
licks. The allen wrench still fit perfectly but it won't move even a
little.

The carbide bits I'm finding are for masonry, hammer drills or
spearpoint for glass and tile.

Maybe I'll continue heating and removing a little at a time

wrote:
If you are using a handheld drill and not getting any chips out, your next
best bet would be to (borrow one if you don't have one) use a benchtop
drill
press set up on blocks, at the correct angle so the quill downfeed would be
constant and steady.

My box-store Ryobi ~10" benchtop could be set up in place, and definitely
has enough power to drill those screws out.

A quality cobalt drill or masonry carbide (and a good cutting lubricant)
should cut the screws with a steady, constant feed, which is often
difficult
to do with a handheld drill.


wrote in message
I have a big drill press but I don't see any way this is happening.
the "piece" I'm working on is 4' long, the axle is 3' wide. The whole
assembly weighs over 200#. The set screw is at about a 45 degree
angle.

I'm using a 1/2" drill at slow speed. I'm able to really lean into it
so I think the pressure is there, at least as much as should be put on
1/8 and 3/16 bits.


I understood the size/scale of the workpiece when it was described as a
garden tractor.

My suggestion was to take a manageable size drill press to the tractor, and
mounting/supporting it in a way that it could feed a drill steadily into the
screw at the proper angle.

The same could also be accomplished with a Cole drill and some metal parts
and clamps.
Benchtop drill presses are generally more common than Cole drills. You
could, possibly, borrow either type.

With either method, the drill feed could be from the top, bottom or
sideways, whichever is more convenient.
The mechanical advantage of a steady quill feed will create chips.

--
WB
..........