Re: [MV] The Cheap Mechanic- Differential Overhaul Update

Alan Bowes (
Sat, 20 Dec 1997 10:21:56 -0700

Rod Diery wrote:
>> Don't use torches or cutting tools or a hammer to remove
>> the bearings. Bearings almost always come off easily when
>> the right tools are used.
> Hi everyone,
> I can not agree with what Alan says here. It is harvest
> time here in Western Australia and I am very busy repairing
> headers or combine harvesters to some of you. In repairing
> these I sometimes have to replace up to 20 or 30 bearings
> a day.
> I always use minimum force in removing old bearings
> but I do not hesitate to use heat, oxy torch or the good
> old hammer if that is what it takes to remove the bearing.
> I have never had a shaft fail directly because of
> the method I have used to remove an old bearing.

Hi Rod,

To tell the truth, I'm not exactly sure what you're disagreeing with.

Unless I misinterpreted your posting, it sounds like you agree with my
advice to Lee not to use torches, cutting tools, or a hammer to remove
the bearings from his pinion shaft...especially since a pinion shaft can
be easily placed in a puller or hydraulic press.

You said it yourself: "Do not use the oxy torch or a hammer if you can
get it off with a puller kit." and "It (using torch, hammer, etc.) is
not a job that the amateur should try unless he or she is supremely

I never said that unconventional methods (heat, torch, percussion,
grinding, etc.) won't serve to remove bearings, but I certainly would
NOT recommend such methods unless the correct tools could not be used.
I've used these "unconventional" techniques myself on numerous
occasions, but I would always caution people to avoid them if possible.

In 35 years of working (and playing) with cars, trucks, aircraft, and
other machinery, I've never had a "normal" (no serious damage or
alteration) bearing or gear that would not press/pull off when the right
tools could be applied. Of course, there were times where I simply
couldn't get a tool on a part, when someone had badly damaged a
component or welded something on, when time constraints didn't allow
full disassembly, when a part was heavily rusted, etc., and in those
cases, yes, I got out the acetylene torch, grinder, hammer, or whatever.

Using heat to remove bearings still makes me nervous, however. I
consider it a last-resort measure, even with experience. Inappropriate
application of heat can cause invisible damage, especially to hardened,
highly stressed, heat-treated parts... changing internal stresses,
creating localized hardness changes, or allowing existing stress risers
to develop into microscopic cracks that may eventually cause an early
failure (which is often attributed to something else). I'm not saying it
can't be done safely, but it's very easy to screw something up by
applying a torch for a few too many seconds.

In the process of keeping farm machinery running, you must encounter
many time-critical situations where you can't always go "by the book." I
imagine that you've developed the skills needed to deal with those
situations, but many (most?) people have not, hence my general advice
not to use those other methods.

Now please excuse me. I've got to go out to the garage and pound off
some stuck bearings.



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