Assembling Case Halves

[TPA1]

When assembling case halves, I see that many people use a heat gun or oven to heat the case and they will put the crank in the freezer to reduce the fit for ease of assembly.

I want to try to keep the entire process on my bench so I will not have to walk to oven, freezer, etc... since my oven and freezer are in the house and not in my shop.

I have a heat gun for the cases, but I want to try the canned computer duster spray to freeze the crank, that way it will be ready at my bench without the need for a freezer, plus the spray can has the potential to get the shaft way colder than the freezer will.

So my question is, has anyone tried it before? You turn the can upside down so it will spray the liquid out and cryogenically freeze the shaft. Is there too much material in the shaft for the spray to adequately remove the heat?

 

[Redfin]

No need to cool the crank.

 

[Czed]

When assembling case halves, I see that many people use a heat gun or oven to heat the case and they will put the crank in the freezer to reduce the fit for ease of assembly.

I want to try to keep the entire process on my bench so I will not have to walk to oven, freezer, etc... since my oven and freezer are in the house and not in my shop.

I have a heat gun for the cases, but I want to try the canned computer duster spray to freeze the crank, that way it will be ready at my bench without the need for a freezer, plus the spray can has the potential to get the shaft way colder than the freezer will.

So my question is, has anyone tried it before? You turn the can upside down so it will spray the liquid out and cryogenically freeze the shaft. Is there too much material in the shaft for the spray to adequately remove the heat?

View attachment 94829

@Mattyo
Has many very long youtube vids
On using simple tool's
Without heat.

 

[Mattyo]

@Mattyo
Has many very long youtube vids
On using simple tool's
Without heat.

Yup....that's me....long vids hehe

 

[Mattyo]

http://opeforum.com/threads/one-case-tool-to-rule-them-all.7059/

 

[Tor R]

Heat and cold can do wonderful things, thats how most saws has been build for decades, personally I prefer to knock them together with proper service tool, but I use heat to mount the bearings in the case, will never slap them bearings home in a case without heathing up the case first

Them saws without a real bearing pocket is tricky without the correct factory tool.

 

[Al Smith]

There really is nothing to using a freeze,heat assembly method .Stihl recommends installing the bearings the pockets then the crank but you can do it either way .

 

[Whitty21]

Put the bearings in the freezer for a while. Take them out. Heat the case. Drop en in. Can still do it at the bench without leaving. Like its said above, no need to do anything to the crank

 

[NCFarmboy]

Highly recommend Mattyo's crank install tool. It works amazing.
Shep

 

[drf256]

Heating the Case half’s does a lot more than cooling the bearings or crank.

+1 on Mattyo’s Crank tool.

 

[BrokenSVT]

I concur with these fellows. It doesn't even take paint-blistering heat usually. I've dropped bearings and cranks in using the wife's hairdryer's turbo setting.

 

[cus_deluxe]

I just rock the $12 heat gun, didnt really notice a difference on ones where i put stuff in the freezer, except for a bunch of condensation on bearings/crank haha.

 

[mdavlee]

I got some stuck part way when freezing the crank bearings. Condensation made it worse than room temperature. Oven at 350 for 30 minutes will let you drop bearings in completely by hand.

 

[Adirondackstihl]

Yesp...

Freezing a bearing is only a difference of maybe 70 degrees from room temperature. Not enough to make a difference IMO.
Heat on the other hand.........

 

[NCFarmboy]

I use a Fry Daddy w synthetic oil heated to 350* to heat bearings.
Shep

 

[Tor R]

I freeze the bearings on saws like 550, 346 PTO, 242 PTO.
Normally I have to heat up the cases to around 200 degree celsius, froozen bearings reduce the heat down 40-50 degree celsius.
I'm not afraid for the bearings but I dont like 200 degree celsius for the pto seals.
I get rid of the condensation to blast the bearing clean with air and then a good dose oil.

Them service tools are worth every penny


For them who struggle to keep control of the conrod while we use both our hands to crank the case together, flip the crankcase upside down when you start to crank them together, that conrod will point down the whole time in that position

 

[Mattyo]

My tools are used one handed ...which means you can control the con rod with the other hand if you like.

I'm fine with putting the bearings in the case with heat, if that's what you want to do. But after that, no more heating bearings up to try to slide a cold crank in for me. Half the time it gets stuck halfway, then you are using a hammer the rest of the way. OR, another issue is sealant. Some guys use sealant on the case gasket. If you heat the case halves to try to get the crank in ... then you have exceptionally narrow windows to get the crank in the bearings and the case halves together. what if it gets stuck? what if the heat messes with the sealant? I dunno, too many variables going all at once. My case tools put cranks in bearings (and therefore case halves together) in the most controlled way possible, with no lateral force on the bearings, and at room temp, one handed

I've done this enough to get frustrated enough to now have a set of tools that works. as @Tor R pointed out, the oem tools are awesome, but they are also specific to certain models, brand specific, and are two handed

then again, if you could dip the crank in liquid nitrogen you might have something

 

[Tor R]

My tools are used one handed ...which means you can control the con rod with the other hand if you like.

first time I did it all wrong, the con rod was a big problem, after that I flipped the case upside down and I've never had any problems with the conrod.

I've done this enough to get frustrated enough to now have a set of tools that works. as @Tor R pointed out, the oem tools are awesome, but they are also specific to certain models, brand specific, and are two handed

most of them factory tools has one or two sides of the socket to knock in the seals with. 4 kits is what people need to cover 90% of Huskies lineup and two hands

Doesnt mather if its factory tools or your tool kit, both does a superb job

 

[TPA1]

Well...I tried it. Sorry no photos or video. There are pluses and minuses.

I started with the PTO side. The bearing and seal were already installed (this was one of the Huztl kits). I heated the case with the heat gun to somewhere around 140F (guessing, I could still handle it for a second or two at a time) then turned the can upside down and sprayed about 1/4 of the can slowly onto the bearing journal and the adjacent lambchop (as Afleetcommand calls it). I didn't get a temperature measurement on the crank either, but I was easily below zero. Here is a dude demonstrating it's temperature reducing ability (although his application is slightly different)

So I had, at a minimum, a 140F temperature differential, and the crank dropped right in.

The downside is that the spray leaves behind some type of oily residue after the volatile part evaporated. I wiped it off with a clean rag which also took the frozen condensation with it.

Mattyo is absolutely correct in that it is impossible to juggle the heat gun, glue, computer duster, and parts all at the same time. I think my glue dried but I will do the pressure test on it later to see how it turned out.

The flywheel side slid right on and left about 1/8" gap between halves, and the bolts pulled it the rest of the way up.

Thanks for all the suggestions

 

[TPA1]

I use a Fry Daddy w synthetic oil heated to 350* to heat bearings.
Shep

Are those good with fries?