Bearing Replacement Idea

[Warped5]

While chatting with a buddy today, a thought occurred to me .... (REALLY odd for a Sunday)

Many of us have done the 'heat the case halves and drop in the frozen bearings' operation.

Has anyone tried dry ice to chill the bearings?

 

[cus_deluxe]

i do it. gotta think it cant hurt. funny, i talked with an old timer friend of mine a couple days ago. he told me to set bearings on an incandescent light bulb for a while and the install on the crank. more than one way to skin a cat and stuff.

 

[cus_deluxe]

i misread teds original post. i dont use dry ice, sorta glossed over that part haha. still cant see it hurting anything

 

[Warped5]

The buddy I was chatting with worked for Allis Chalmers years ago.

They would freeze valve guides in a freezer (at about zero) prior to installation and would occasionally run into 'difficulties'. One of the engineers suggested using dry ice; he said it made a huge difference.

....so I wondered if anyone around here had tried it.

 

[Al Smith]

As a matter of record years ago the hardened valve seats in Ford 429 V8 engines used liquid nitrogen to shrink the inserts .I suppose you could use a CO2 fire exting1sher and get the same results . Once again another method of skinning the same cat .

 

[Genius]

This past weekend dad went to a neighbors shop to give him a hand. The guy was replacing bearings on his corn planter. He had a liquid nitrogen tank he was dipping the bearings in.

 

[Mastermind]

Dry ice would help.......but just a household freezer is not cold enough to make a difference in my humble opinion.

 

[bplust]

I like to call deep winter up here "rebuild season". Those -15 to -40 Fahrenheit night temps do have an upside. Case halves on the woodstove, crank & bearings outside.

 

[Genius]

I like to call deep winter up here "rebuild season". Those -15 to -40 Fahrenheit night temps do have an upside. Case halves on the woodstove, crank & bearings outside.

I guess there is ONE upside then about Vermont

 

[Lone Wolf]

I like to call deep winter up here "rebuild season". Those -15 to -40 Fahrenheit night temps do have an upside. Case halves on the woodstove, crank & bearings outside.

There it is!

 

[Jughead]

in my experience bearings in the freezer has caused me problems.it seems to cool the cases just enough at 275f to cause the bearing to stick halfway.partly i believe is because the bearings start sweating as soon as they hit the warmer air outside of the freezer.for me i've had much better luck with room temp bearings and the cases right at 290-325f.

 

[Warped5]

in my experience bearings in the freezer has caused me problems.it seems to cool the cases just enough at 275f to cause the bearing to stick halfway.partly i believe is because the bearings start sweating as soon as they hit the warmer air outside of the freezer.for me i've had much better luck with room temp bearings and the cases right at 290-325f.

During me recent frustrations with my Husky 288 rebuild, I ran into the exact same thing. Kinda 'forced' me to go consult the Service Manual. I had always heated cases to 300 F .... the SM said to heat them to 300 .... Centigrade (about 400 F).

Made all the difference in the world ... bearings literally dropped in.

 

[stihl_head1982]

So we are saying room temperature, not "household" freezer works better?
You guys using an oven, heat gun, or map gas torch?

 

[Warped5]

Use the small chest freezer we have. Have a toaster oven for cooking the cases.

 

[Jughead]

wood stove or heat gun for me.used the old ladys oven one time and got a *b-wordin.

 

[Lone Wolf]

wood stove or heat gun for me.used the old ladys oven one time and got a *b-wordin.

Were they oily and smoking in there?

 

[jmssaws]

Heat gun and a freezer is all I use and have done hundreds problem free.
If your having trouble your probably not getting the case hot enough.

 

[Al Smith]

You can probably do better with a heat gun because you can localize the heat around the bearing pocket .If you bake the case in an oven like so much apple pie the whole dang thing gets hot .Try picking up 400 degrees of aluminum sometime and see how you like it .

Right out of the "book" freeze the bearing heat the cases ,install in the cases .Then use a big soldering iron to heat the inner race ,install the crank .Do likewise on the other side .

I've done it both ways,bearings in the case and bearings on the crank .
On the shaft first couple methods .Bearing heater which I doubt many have including myself .Soldering iron which I have several or heat them up in oil to about 250 degrees .Any method will work .

Whatever you do don't be beating on them with a big ball peen or a brass hammer like trying to drive a railroad spike .

 

[jmssaws]

I have put the bearings on the crank and froze all of it and I've put the bearings in the case and froze the crank.

If the case is hot enough it will fall together even with room temp bearings.
I use to be afraid of getting things to hot but I got over that after a hundred or so.
I do lots of bearing jobs for people.

 

[Al Smith]

After thought .Way back when in my teenage juvenile deliquent days we used to cool off cases of beer with a CO2 fire extingisher .That would dang sure freeze a bearing .If you did it too long it would freeze the beer .