Freezing Bearings For Instal

[Vintage Engine Repairs]

Hi, I have done this test a number of times but decided to get it on camera. I thought it may be interesting and save you wasted time with a freezer.

it’s worth mentioning liquid nitrogen or dry ice temperatures which are between -80 to -200c of course there will be a useful advantage for even chainsaw bearing instal.

I was just testing if a home freezer has the ability to make any practical difference in installing bearings into chainsaw pockets (which so many teach and recommend as gospel).

Precision machine / milled / lathed fits where the mating surfaces are perfectly round within microns, any temp change makes a big difference to the fitment, that’s a precision fitment. A 40 year old cast chainsaw bearing pocket is far from precision.

 

[cuinrearview]

You should try this with a five series Husky.

 

[Mastermind]

Heat the case. That helps.

Freezing bearings is a waste of time. To go from 80 degrees to 20 is only a 60 degree difference. To go from 80 to 350......well that matters.

 

[huskihl]

Heat the case. That helps.

Freezing bearings is a waste of time. To go from 80 degrees to 20 is only a 60 degree difference. To go from 80 to 350......well that matters.

Bingo

 

[cuinrearview]

Still loving the day I found the $20 no. 1 Atlas press at the old machine shop.

 

[Mastermind]

I had one.....sold it before I got interested in saws.

 

[davidwyby]

I am reasonably certain that magnesium expands and contracts with temp changes considerably more than steel.

 

[Terry Syd]

I do both, I freeze the bearings in the freezer over night and then heat up the cases with a butane torch before install. I like the bearings to just 'drop in' without any force that can distort the bearing surface.

 

[Wonkydonkey]

When I rebuilt my 044 and a 026, I tried slightly different methods.

I found freezing the bearings only helped cool the mag case quickly. If it didn’t drop straight in (it touched the side) then I had to use a drift quickly on the outside edge of the bearings.

But if when I were to it again, I don’t think it’s worth a couple thousands difference in bearing size you get by freezing them. The most important thing is case temp, and we can all see how quickly the case cools and thus contracts in tom's vid at the top.

thanks for do the experiment Tom

 

[smokey7]

My opinion is just heat the case dont take the risk of getting moisture and rust on the bearing.
Try not to hit the bearing at all if possible.

 

[drf256]

I used to freeze the bearings. I found it made very little difference.

 

[Stihl working Hard]

I used to freeze the bearings. I found it made very little difference.

So did I I just heat the cases

 

[van462]

A 1.5" bearing will shrink to around 1.4991 going from 80 to 32 degrees. The thou may help I often find any residual greases that harden up counteract the effect in smaller bearings. The larger 9 inch bearings I work with with, we chill to -100 and get around .020" (calculated) reduction. Never have measured the change, but they go from an interference fit to a ring toss.

 

[kneedeepinsaws]

Heat the case. That helps.

Freezing bearings is a waste of time. To go from 80 degrees to 20 is only a 60 degree difference. To go from 80 to 350......well that matters.

Larger delta T is a bearing in the seat yo

 

[Mastermind]

Larger delta T is a bearing in the seat yo

I'm not sure what that means.

 

[kneedeepinsaws]

I'm not sure what that means.

If you were a plumber you would get it.

 

[Mastermind]

If you were a plumber you would get it.

@Fruecrue

 

[davidwyby]

I'm not sure what that means.

Delta means difference

t prolly temp

 

[Fruecrue]

@Fruecrue

Dammit.

 

[Stihl working Hard]

Dammit.

We have a winner