Driving Master Pins into Track Linkage - take the fun out.

[slwbid]

When I was a teenager, I helped my dad for a while working on big trucks (18 wheeler type). His shop was next door to a compressed Gas company and he had some buddys over there.
One day when rebuilding a motor and preparing to drive the sleeves in, I watched in amazement when he went next door and came back with a 5 gallon bucket of liquid Nitrogen. It was steaming to beat the band at room temp.

He would take the sleeves, hold them on top edge with Channel Locks, dip them in the Nitrogen, then drop them in the block. They literally fell into place. Of course when they warmed back up, the were tight.

Remembering this trick, I've used it over the years. I don't have access to a bucket of liquid Nitrogen but when needing to drive a master pin in, I will leave it in the Freezer overnight (or longer).
Also, I purchase a spray can of what I suspect is compressed nitrogen (or some other gas that is really cold at normal atmospheric pressure). It is sold in Computer supply places in small 10-12 oz spray cans. It is normally used to super cool computer parts I think when trying to salvage some data off computer parts that are defective and inoperable at room temp.

Back to Story.
Take pin out of freezer and spray this liquid all over the pin (careful to not spray any exposed skin). nstick the pin in place and start tapping. Light blows from a hand held sledge should be all you need.

Hope this helps someone
slwbid
Stacy

[Stan Disbrow]

Hi,

Oh, yes. Very old trick, the freezer. So old, I thought everyone knew it.

The can of spray would be Freon. Also an old trick. Comes in two kinds of cans. The Dust Off kind, which has no dip tube so it blows gas when upright. And, the Freeze Spray kind which has a dip tube so it blows liquid when upright.

Of course if you have a can of Dust Off and need liquid to spray out, just flip it upside down. Freeze Spray is how every electronic service tech has always found intermittent components.

You can also use a CO2 fire extinguisher. That puts out a cold 'snow'.

I would not use LN2, though. At minus 340 deg F it is way too cold. If one dropped the sleeve, it would likely shatter as of it were made of glass. LN2 is used with a control valve to chill Cold Ovens and such. I use a lot of it in my work with electron microscopes and material analyzers.

One has to be careful not to get any LN2 on oneself. It will instantly kill any areas of skin it contacts. It makes cold burns way worse than the hot burns you'd get from red hot steel.

Stan

[slwbid]

Stan, you are quite right about Liquid Nitrogen. It is very dangerous stuff. Spilling on oneself would be tantamount to spilling napalm on oneself. A droplet splattered in eye and that eye can be kissed goodbye.

Also my memory from 50 years ago is probably not quite accurate. My dad probably did not 'drop' the sleeves in, he probably very gingerly let them ease in.

So, play it safe and don't cool pins with liquid nitrogen. Stick with Freezer and Freon.

Thanks Stan.