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-   -   Oiling a bearing. (https://www.diybanter.com/uk-diy/607027-oiling-bearing.html)

Dave Plowman (News) March 15th 18 10:45 AM

Oiling a bearing.
 
The rear wiper motor on the old car failed in a cloud of smoke the other
day. The motor had been replaced a few years ago with a NOS one, so not
had that much use.

It's a very easy thing to strip down being an oldish design, and on doing
so obvious the motor had seized. And seemed to be the bearing on the far
end of the motor from the brushes. It is a self aligning plain bearing -
with a single ball the middle of the shaft to take the thrust.

A new motor isn't a vast price, but since it will be from the same NOS
source, may well have dried out in storage of some 30 years.

So to the question. Is there a best oil to use for this, and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.

The other end of the motor goes into the gearbox. Which has grease in it.
Perhaps some of that finds its way into the front motor bearing, as that
seemed OK.

--
*I must always remember that I'm unique, just like everyone else. *

Dave Plowman London SW
To e-mail, change noise into sound.

The Other Mike[_3_] March 15th 18 11:29 AM

Oiling a bearing.
 
On Thu, 15 Mar 2018 10:45:10 +0000 (GMT), "Dave Plowman (News)"
wrote:

So to the question. Is there a best oil to use for this, and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.



IIRC the original 1960's BMC and maybe Haynes manuals had the instructions for
reimpregnating the end bearings in Lucas starter motors / dynamos and maybe
wiper motors

Plain oil maybe 30 weight, drop in the bearing heat for a few hours at maybe 100
deg C and maybe leave overnight. But i'll admit most of that is a guess on what
i'd do :)

--

Peter Parry March 15th 18 11:43 AM

Oiling a bearing.
 
On Thu, 15 Mar 2018 10:45:10 +0000 (GMT), "Dave Plowman (News)"
wrote:


So to the question. Is there a best oil to use for this,


Generally any light oil should do. ISO VG (SAE 30) is the oil used to
impregnate Oilite bearings during manufacture.

and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.


The best way is to get a discarded fridge compressor in working order
and a fairly robust glass jar with a tin lid. Jam jar is usually OK.

Connect up the compressor and find which pipe is out and which in. To
the jam jar lid solder (soft solder is fine) a piece of metal tube of
same/similar OD as the fridge compressor inlet tube.
Use some reinforced plastic tube to connect the jar lid to the
compressor.

Try to clean as much old oil out by baking the bearing at 200degC
(domestic oven) for half an hour or so.

Part fill the jam jar with warm light oil, place the bearing in the
oils so it is fully submerged, fit lid to jar and turn on compressor
to extract air. You will see bubbles rising from the bearing
material. Hold vacuum until bubbles stop, release, wait 5 mins and
repeat cycle several times. On the last cycle leave the bearing in
the oil for an hour after finally releasing the vacuum.

Glass jars are fine under vacuum but (obviously) not pressure. The
fridge compressor makes a fine vacuum pumps and no pressure switch is
required as the high pressure outlet is simply open to air.

Harry Bloomfield[_3_] March 15th 18 11:45 AM

Oiling a bearing.
 
The Other Mike presented the following explanation :
Plain oil maybe 30 weight, drop in the bearing heat for a few hours at maybe
100
deg C and maybe leave overnight. But i'll admit most of that is a guess on
what
i'd do :)


I would add to that, soaking the bearing in petrol overnight, to
dissolve out the existing lub, before allowing to dry and then
re-lubing..

The Natural Philosopher[_2_] March 15th 18 01:32 PM

Oiling a bearing.
 
On 15/03/18 11:29, The Other Mike wrote:
On Thu, 15 Mar 2018 10:45:10 +0000 (GMT), "Dave Plowman (News)"
wrote:

So to the question. Is there a best oil to use for this, and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.



IIRC the original 1960's BMC and maybe Haynes manuals had the instructions for
reimpregnating the end bearings in Lucas starter motors / dynamos and maybe
wiper motors

Plain oil maybe 30 weight, drop in the bearing heat for a few hours at maybe 100
deg C and maybe leave overnight. But i'll admit most of that is a guess on what
i'd do :)

Lot of experienc ogf this on model motors: It its phosphor bronze plain
bearing really any light machine oil will do

3 in 1


You can do the 'heat it and soak it' and it will last longer that way,
but just OILING it is good for a year usually


--
You can get much farther with a kind word and a gun than you can with a
kind word alone.

Al Capone



harry March 15th 18 04:29 PM

Oiling a bearing.
 
On Thursday, 15 March 2018 10:45:19 UTC, Dave Plowman (News) wrote:
The rear wiper motor on the old car failed in a cloud of smoke the other
day. The motor had been replaced a few years ago with a NOS one, so not
had that much use.

It's a very easy thing to strip down being an oldish design, and on doing
so obvious the motor had seized. And seemed to be the bearing on the far
end of the motor from the brushes. It is a self aligning plain bearing -
with a single ball the middle of the shaft to take the thrust.

A new motor isn't a vast price, but since it will be from the same NOS
source, may well have dried out in storage of some 30 years.

So to the question. Is there a best oil to use for this, and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.

The other end of the motor goes into the gearbox. Which has grease in it.
Perhaps some of that finds its way into the front motor bearing, as that
seemed OK.




http://www.practicalmachinist.com/vb...earing-213850/

[email protected] March 15th 18 04:38 PM

Oiling a bearing.
 
On Thursday, 15 March 2018 11:43:57 UTC, Peter Parry wrote:
On Thu, 15 Mar 2018 10:45:10 +0000 (GMT), "Dave Plowman (News)"
wrote:


So to the question. Is there a best oil to use for this,


Generally any light oil should do. ISO VG (SAE 30) is the oil used to
impregnate Oilite bearings during manufacture.

and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.


The best way is to get a discarded fridge compressor in working order
and a fairly robust glass jar with a tin lid. Jam jar is usually OK.

Connect up the compressor and find which pipe is out and which in. To
the jam jar lid solder (soft solder is fine) a piece of metal tube of
same/similar OD as the fridge compressor inlet tube.
Use some reinforced plastic tube to connect the jar lid to the
compressor.

Try to clean as much old oil out by baking the bearing at 200degC
(domestic oven) for half an hour or so.

Part fill the jam jar with warm light oil, place the bearing in the
oils so it is fully submerged, fit lid to jar and turn on compressor
to extract air. You will see bubbles rising from the bearing
material. Hold vacuum until bubbles stop, release, wait 5 mins and
repeat cycle several times. On the last cycle leave the bearing in
the oil for an hour after finally releasing the vacuum.

Glass jars are fine under vacuum but (obviously) not pressure. The
fridge compressor makes a fine vacuum pumps and no pressure switch is
required as the high pressure outlet is simply open to air.


the oil used in modern fridges seizes the compressor if exposed to the air. The first thing you need to do is flush it out. Also be aware that release of some refrigerants is a offence.

The oil to use is ATF. It's the best unseizing stuff there is. If you need something thinner it could be mixed with light mineral oil etc.


NT

Rob Morley March 15th 18 05:12 PM

Oiling a bearing.
 
On Thu, 15 Mar 2018 10:45:10 +0000 (GMT)
"Dave Plowman (News)" wrote:

The rear wiper motor on the old car failed in a cloud of smoke the
other day. The motor had been replaced a few years ago with a NOS
one, so not had that much use.

Did you clean and re-grease the gearbox when you fitted the motor?
I've had wipers completely seize from hardened grease in the gearbox,
wonder if that might have contributed to your motor failure.


FMurtz March 16th 18 12:51 AM

Oiling a bearing.
 
harry wrote:
On Thursday, 15 March 2018 10:45:19 UTC, Dave Plowman (News) wrote:
The rear wiper motor on the old car failed in a cloud of smoke the other
day. The motor had been replaced a few years ago with a NOS one, so not
had that much use.

It's a very easy thing to strip down being an oldish design, and on doing
so obvious the motor had seized. And seemed to be the bearing on the far
end of the motor from the brushes. It is a self aligning plain bearing -
with a single ball the middle of the shaft to take the thrust.

A new motor isn't a vast price, but since it will be from the same NOS
source, may well have dried out in storage of some 30 years.

So to the question. Is there a best oil to use for this, and how to soak
the bearing bush? I'm assuming it is a porous type which soaks up oil.

The other end of the motor goes into the gearbox. Which has grease in it.
Perhaps some of that finds its way into the front motor bearing, as that
seemed OK.




http://www.practicalmachinist.com/vb...earing-213850/

We used to put the bearing between thumb and forefinger full of oil and
squeeze, you can see the oil coming out of the pores of the bearing.


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