"Eric" <say.no@spam.now> wrote
> Caroline wrote:
> > Cobalt drill bits are essential but still very, very slow, even with
> > the best cutting oil.
>
> This is by design. Cobalt bits are made for drilling into hardened metals.
> As such, the angle of the cutting edges is shallower than it is on high
> speed steel bits. This enables the drill bit to take off smaller chips of
> metal which has advantages when drilling into hardened metal.
>
> A disadvantage with cobalt bits is that they're typically rather brittle and
> easy to break. I've broken large bits simply by accidentally dropping them
> onto concrete. I've also broken smaller ones by applying too much side
> pressure while drilling.

Thanks, Eric and John Ings, for the additional information.

I soaked the other side's lower control arm outboard and middle bolts as best I
could several times in the last few weeks. Today I again went under the car and
tried to free them. It feels like they are just going to shear, like the first
side. The inboard bolt came out fairly easily, though.

Now the only battle is to resist perfectionism and instead be completely
rational: Do not attempt to remove this other side's control arm. The first
side's shock was in good condition. I have no symptoms of poor performance. I'll
save $68 in parts costs and perhaps a lot of annoyance. I predict the car will
be fine, rear suspension wise for another five years, particularly in my new
locale (a much drier, almost snow-free, Western climate).

But if by chance that puppy should break before the engine does, I'm ready!

Thanks again, all.

 

"Eric" <say.no@spam.now> wrote
> Caroline wrote:
> > Cobalt drill bits are essential but still very, very slow, even with
> > the best cutting oil.
>
> This is by design. Cobalt bits are made for drilling into hardened metals.
> As such, the angle of the cutting edges is shallower than it is on high
> speed steel bits. This enables the drill bit to take off smaller chips of
> metal which has advantages when drilling into hardened metal.
>
> A disadvantage with cobalt bits is that they're typically rather brittle and
> easy to break. I've broken large bits simply by accidentally dropping them
> onto concrete. I've also broken smaller ones by applying too much side
> pressure while drilling.

Thanks, Eric and John Ings, for the additional information.

I soaked the other side's lower control arm outboard and middle bolts as best I
could several times in the last few weeks. Today I again went under the car and
tried to free them. It feels like they are just going to shear, like the first
side. The inboard bolt came out fairly easily, though.

Now the only battle is to resist perfectionism and instead be completely
rational: Do not attempt to remove this other side's control arm. The first
side's shock was in good condition. I have no symptoms of poor performance. I'll
save $68 in parts costs and perhaps a lot of annoyance. I predict the car will
be fine, rear suspension wise for another five years, particularly in my new
locale (a much drier, almost snow-free, Western climate).

But if by chance that puppy should break before the engine does, I'm ready!

Thanks again, all.

 

"Eric" <say.no@spam.now> wrote
> Caroline wrote:
> > Cobalt drill bits are essential but still very, very slow, even with
> > the best cutting oil.
>
> This is by design. Cobalt bits are made for drilling into hardened metals.
> As such, the angle of the cutting edges is shallower than it is on high
> speed steel bits. This enables the drill bit to take off smaller chips of
> metal which has advantages when drilling into hardened metal.
>
> A disadvantage with cobalt bits is that they're typically rather brittle and
> easy to break. I've broken large bits simply by accidentally dropping them
> onto concrete. I've also broken smaller ones by applying too much side
> pressure while drilling.

Thanks, Eric and John Ings, for the additional information.

I soaked the other side's lower control arm outboard and middle bolts as best I
could several times in the last few weeks. Today I again went under the car and
tried to free them. It feels like they are just going to shear, like the first
side. The inboard bolt came out fairly easily, though.

Now the only battle is to resist perfectionism and instead be completely
rational: Do not attempt to remove this other side's control arm. The first
side's shock was in good condition. I have no symptoms of poor performance. I'll
save $68 in parts costs and perhaps a lot of annoyance. I predict the car will
be fine, rear suspension wise for another five years, particularly in my new
locale (a much drier, almost snow-free, Western climate).

But if by chance that puppy should break before the engine does, I'm ready!

Thanks again, all.