Best Bearing Installation Alignment Methods?

[Jacob J.]

Have any video of how to put the bearings, crank and case back together using the Stihl tools? I'm going to attempt it in a few weeks, would have been tonight if I wasn't leaving for business.

They're nothing special. You could do the same thing with a good selection of sockets and a brass hammer.

The Stihl "installation sleeve" is nothing more than a pipe with a flange that is almost the same diameter as the outer race on the bearing. It sits on the bearing
and supports it fully while you tap on it. That way you're not pounding on the inner race and possibly damaging the rollers.

 

[watsonr]

Got it, thought maybe I got burned and didn't get all the attachments to the tool set.

:glasses-cool: and thanks!

 

[Fish]

You know what you are doing, nice to see. You understand how the coefficient of linear expansion works as well, bravo. Excellent post bro.

He also knows his way around a Mammary Bar!!!!

 

[PogoInTheWoods]

I'm still wondering about using the oil pump as the "stop" for the bearing on the clutch side...

It's up against it all nice and tidy, but still sorta cocked in the seat. Will installing the crank (minus the oil pump) and a whack or two with a deadblow get things centered and then the "pump alignment" just fends for itself when it gets re-installed?

Seems like a real weak approach for installing the bearing with any precision.

 

[PogoInTheWoods]

I don't know how everyone else does this but this how I do them....now comes the beauty....the second case half will nearly always dissapate enough heat to the other side enough to allow both outer bearing races to move and you to shift the crankshaft to the center with hardly any effort....no beating, striking,pressing or tapping required and there is enough time to get the bearings centered and free spinning....

And the crankshaft was off center to begin with because.....? And it then becomes "centered" by the "shift the crankshaft to the center with hardly any effort" process by what means and compared to what? And if effort were required, what type, and how would it be applied? And what was off-center? The bearings, the crank, or all three?

And with all due respect, if you can heat a bearing in a basic toaster oven, why can't one be frozen in a conventional freezer?

After all, we're only talking minor linear coefficient alterations for a very brief time to affect an easier "fit" between two components -- one heated, the other cooled.

By no means am I trying to be a smart-ass, here. I'm just back at it this afternoon with these pain-in-the ass 036's and hoping to figure out the best way to do the bearings and crank replacement with the least amount of hassle and the most precise outcome.

BTW, my kid's college toaster oven turned out to be the cat's ass for this stuff. Great tip -- from his mom after I stunk up the kitchen using her rig the other night and ending up with cornbread that tasted like my garage the next morning. Oh well, more cornbread for me!

 

[Mastermind]

I don't know how everyone else does this but this how I do them. First I don't bother trying to freeze the bearings, it would make a difference if you used dry ice but a conventional freezer does not have the temp differential to be of much help IMHO... I have an old used electric toaster oven in the shop that I use to heat whatever parts I'm dealing with...so far this has accepted cases up through saws in the 70E Jonsereds size. The main bearings I put on the crank first....put a bearing in the oven, 200-210 degrees for 10 mins...grab with a welding glove and drop right onto the crank held vertically in a vice....by the time the second bearing is ready the first has cooled plenty so I flip the crank end for end and do the same thing...no beating, tapping etc. required, they just fall right into place. That done it's time for a case half..in the oven it goes..usually 160-180 for ten mins..pull it out and place the crank and main bearing in it...you have to not waste time as a mag case will dissapate heat rather quickly. Anyway it goes all the way in.....heat the other case half the same amount of time and when everything is ready (gasket in place and 3 screws and T handle ready) put them right together and quickly snug the screws up...now comes the beauty....the second case half will nearly always dissapate enough heat to the other side enough to allow both outer bearing races to move and you to shift the crankshaft to the center with hardly any effort. The only thing is you have to do is move swiftly and accurately...no beating, striking,pressing or tapping required and there is enough time to get the bearings centered and free spinning....this has always worked super for me......just one of many ways I'm sure..

Yep that's the ticket. I've tried it many different ways but the bearings on the crank first is the way to go. I've never seen the need to freeze anything either...

 

[PogoInTheWoods]

Yep that's the ticket. I've tried it many different ways but the bearings on the crank first is the way to go. I've never seen the need to freeze anything either...

'Nuther question...

Should I now pop the bearings out of the case halves and start over? Would you?

I just want these damned things back together and out of my hair so I can get to my 066 project!!!

Just shufflin' along here, gang. Always appreciate the help.



Poge

 

[Mastermind]

'Nuther question...

Should I now pop the bearings out of the case halves and start over? Would you?

I just want these damned things back together and out of my hair so I can get to my 066 project!!!

Just shufflin' along here, gang. Always appreciate the help.



Poge

The reason some heat the case halves.....drop the bearing......then the crank is because when done just right the bearing will soak up the heat from the case and allow the crank to slide right in.

I do it bearing on crank first because I feel more comfortable lining the bearing up in the bore that way.

The one pic with the bearing cocked I would remove.

 

[PogoInTheWoods]

The reason some heat the case halves.....drop the bearing......then the crank is because when done just right the bearing will soak up the heat from the case and allow the crank to slide right in.

I do it bearing on crank first because I feel more comfortable lining the bearing up in the bore that way.

The one pic with the bearing cocked I would remove.

Thanks, Randy.

Yeah, I popped the bearing in the pic and re-installed it today with much better results. Still question using the oil pump as a stop for the installation -- which is a very good case for putting the bearing on the crank first, at least on the 034/036.

Have bearings on crank for my second one with 1st case half in the oven as I type to see how that approach goes for a maiden voyage using that technique.

 

[Cantdog]

And the crankshaft was off center to begin with because.....? And it then becomes "centered" by the "shift the crankshaft to the center with hardly any effort" process by what means and compared to what? And if effort were required, what type, and how would it be applied? And what was off-center? The bearings, the crank, or all three?

And with all due respect, if you can heat a bearing in a basic toaster oven, why can't one be frozen in a conventional freezer?

After all, we're only talking minor linear coefficient alterations for a very brief time to affect an easier "fit" between two components -- one heated, the other cooled.

By no means am I trying to be a smart-ass, here. I'm just back at it this afternoon with these pain-in-the ass 036's and hoping to figure out the best way to do the bearings and crank replacement with the least amount of hassle and the most precise outcome.

BTW, my kid's college toaster oven turned out to be the cat's ass for this stuff. Great tip -- from his mom after I stunk up the kitchen using her rig the other night and ending up with cornbread that tasted like my garage the next morning. Oh well, more cornbread for me!

I can't say why your crank was off center....but what I meant in "with little effort" was by hand...once you get the case halves together and the three screws snugged...you put a little pressure on the crank with your hands and keep it on...the second (hot) case half will heat up the first case half and you can feel the crank starting to shift that's when you center the crankshaft in the cases you have maybe 2 min to get it centered and any bearing preload eliminated...it's all in the "feel"

As far as the freezer thing goes...think about it...say your bearings are 72 degrees, your freezer goes down to around zero so you can so you can make a 72 degree change....the oven will go to 500 degrees for a 428 degree change from the 72 dehgree starting point......as you can see it's much easier to go up than down because you are going to need atleast a 140 change from 72 to get things together easily. I am not saying you could not do the change with just freezing but it would require dry ice, liquid ox or nitrogen.....just alot easier to turn the knob up on the toaster oven!! I learned some of this from my dad who worked on the Presidential class destroyers in the big one. He said the ring gears that ran the huge 16" gun turrets were held in the deck only an interference fit. They user to pack the ring gears in burlap bags of dry ice and shrink it down until it would fall into place, then twenty guys with 10 lb hammers would pound on it as it expanded so the expansion would be more or less equal everywhere. On one day a guy missed his blow and his 10 lb hammer got caught in the end gap as it was closing....he tried to get it free..broke the handle off it...the ring gear continued to expand until the end gap was completely closed..pinching the maul head completely off leaving it missing a very strange right angle piece out of the middle....

 

[minuteman tree]

I just got done redoing a 272xp. I went slow with a hammer and large socket. They went in fine.

 

[Stihlofadeal64]

opcorn:

Lots of heavy weights weighing in. This is fascinating.

opcorn:

 

[PogoInTheWoods]

Well, I now know why the oil pump is used as the "stop" for the clutch side bearing on the 1125 series and why at least that side should probably always be installed in the case vs. on the crank.

Anyone care to take a guess why?

opcorn:

Poge

edit: I didn't make much progress on the rebuilds today, but I learned a lot!

 

[Mastermind]

Well, I now know why the oil pump is used as the "stop" for the clutch side bearing on the 1125 series and why at least that side should probably always be installed in the case vs. on the crank.

Anyone care to take a guess why?

opcorn:

Poge

Is the counterweights rubbing the case? :msp_biggrin:

 

[PogoInTheWoods]

Is the counterweights rubbing the case? :msp_biggrin:

Which side?:msp_biggrin:

Yeah, man. What a learning experience today. Sometimes the book is the way to go for reasons ya probably shouldn't question regardless of who says they have the better mousetrap.

Bearings on the crank first for 1125 cases is not the right way to do it. Period.

I know better now.

 

[Mastermind]

Which side?:msp_biggrin:

Yeah, man. What a learning experience today. Sometimes the book is the way to go for reasons ya probably shouldn't question regardless of who says they have the better mousetrap.

Bearings on the crank first for 1125 cases is not the right way to do it. Period.

I know better now.

Bearings on the crank first is the way I do them all. including the 1125 series. I heat the case half....bolt on the pump....drop the bearing/crank in......gasket.....then the other side.

Most all Stihl saws need the pump on to use as a stop/index point for the PTO bearing.

 

[nmurph]

Which side?:msp_biggrin:

Yeah, man. What a learning experience today. Sometimes the book is the way to go for reasons ya probably shouldn't question regardless of who says they have the better mousetrap.

Bearings on the crank first for 1125 cases is not the right way to do it. Period.

I know better now.

Yep...that's why you put them in the cases first. JJ says do it this way: that's good enough for me. I will add that I have only done bearing replacements on Huskies.

 

[PogoInTheWoods]

Bearings on the crank first is the way I do them all. including the 1125 series. I heat the case half....bolt on the pump....drop the bearing/crank in......gasket.....then the other side.

Most all Stihl saws need the pump on to use as a stop/index point for the PTO bearing.

Bearings already on the crank have nothing to do with the pump as a "stop". The bearing on that side will be located too far toward the counterweight if installed on the crank first without appropriate compensation equaling the position of the pump as a "stop" for the bearing -- unless you're one lucky-ass dude every time you do it otherwise, or have a magic bullet you haven't explained yet -- like a spacer on the crank equal to the pump dimension as an index point doing it that way.

Trust me, I'm all for the easy way.

Been tryin' everyone's all day long and still haven't found one that worked as advertised.

Don't get me wrong. I appreciate the input.

Generalities are just that, though. Generalities. Not necessarily applicable to all situations....

Anyway, thanks. I'll get em together one way or another sooner or later.

 

[timmcat]

I have stated before in another thread that the proper way is bearings in the cases first then pull the crank into the bearings. I may be fortunate, maybe not, to have a lathe at my disposal, which makes it much easier to make fixtures for aligning the outer races to the cases on saws like the 034,6 and 026. In every saw I do crank work on I use the husky bearing installers. They are basically threaded internally with either the coarse or fine thread metric size for the flywheel side and externally with a 5/8 fine thread. using those and various combinations of pipes and or spacers you can pull the crank into the bearings cold and your not stressing anything but the threads on the crank because your pulling against the inner race not the outer or case halve. On the clutch side I just use spacers and an old clutch spider. If anyone doubts how this works, look into buying a husky case, they come with the bearings installed. If it was right to put them on the crank first would they do that? Do they send bearings in the case so you'd have to remove them then reinstall them?

 

[Mastermind]

Bearings already on the crank have nothing to do with the pump as a "stop". The bearing on that side will be located too far toward the counterweight if installed on the crank first without appropriate compensation equaling the position of the pump as a "stop" for the bearing -- unless you're one lucky-ass dude every time you do it otherwise, or have a magic bullet you haven't explained yet -- like a spacer on the crank equal to the pump dimension as an index point doing it that way.

Trust me, I'm all for the easy way.

Been tryin' everyone's all day long and still haven't found one that worked as advertised.

Don't get me wrong. I appreciate the input.

Generalities are just that, though. Generalities. Not necessarily applicable to all situations....

Anyway, thanks. I'll get em together one way or another sooner or later.

I must be a lucky dude then. We've done three in the last few weeks with no trouble at all.

I have stated before in another thread that the proper way is bearings in the cases first then pull the crank into the bearings. I may be fortunate, maybe not, to have a lathe at my disposal, which makes it much easier to make fixtures for aligning the outer races to the cases on saws like the 034,6 and 026. In every saw I do crank work on I use the husky bearing installers. They are basically threaded internally with either the coarse or fine thread metric size for the flywheel side and externally with a 5/8 fine thread. using those and various combinations of pipes and or spacers you can pull the crank into the bearings cold and your not stressing anything but the threads on the crank because your pulling against the inner race not the outer or case halve. On the clutch side I just use spacers and an old clutch spider. If anyone doubts how this works, look into buying a husky case, they come with the bearings installed. If it was right to put them on the crank first would they do that? Do they send bearings in the case so you'd have to remove them then reinstall them?

Pulling the crank in is the "proper" way to do it. :msp_wink: