Crank bearing installation question

[StihlEchoingHusky]

So the question is could you use moto seal on the outside race of a bearing as you install the bearing into the case? As a means of "lubricant".plus seal any possible scratches along the way. I've noticed when I install a crank seal with moto seal on it it slides in easier. Or would moto seal cause the bearing to spin? I'm trying to venture away from using heat because of my own anxiety. Even though I keep a temp gun in hand when I heat up a case I'm still always fearful of damaging the bearing pocket. But I I'm curious if theres a way to aid seating the bearing.

 

[hacskaroly]

I don't heat my cases when I install a bearing. I put oil on the outside of the race and in the pocket and then use a bolt with about 8 washers and a nut. I tap the bearing into place to make sure it is barely started and flat then I put in the bolt with four washers on each side and then the nut and then use two sockets to work the bearing into the pocket. If the bearing recesses a little on the inside, I make sure I use washers that are smaller than the pocket so they are easy to get out. No heat needed, therefore I won't burn myself. I work slowly to make sure it stays straight, if I get the hee-bee gee-bees that something is not right, I can stop and reset to make sure things are going well. I have done about five cases so far this way (all the way from a Husky 55 up to a 575 and have not had an issue so far). Not sure about the motoseal.

 

[Stump Shot]

No sealant of any kind is needed heated or not on bearing or seals upon installation.

 

[Mastermind]

Hell boys...I use a damn torch sometimes. No need to overthink it.

 

[Outback]

400f in the barn oven with welding gloves. Bearings fall out and in. Couldn't be easier. Service manuals said 200c in the stihl and husqvarna literature when I started so that's what I do. Plus it bakes the oil out of the magnesium for a good sealing surface.

 

[hacskaroly]

Hell boys...I use a damn torch sometimes. No need to overthink it.

I am one of those that would heat the case, put down the torch and then grab it by the hot spot not thinking and instantly wondering why I didn't have any gloves on....

400f in the barn oven with welding gloves. Bearings fall out and in. Couldn't be easier. Service manuals said 200c in the stihl and husqvarna literature when I started so that's what I do. Plus it bakes the oil out of the magnesium for a good sealing surface.

I have a new to me toaster oven in my shop, I will have to give that a try!! Welding gloves...welding gloves...welding gloves....have to remember the welding gloves!!

 

[Mammyrat]

Not sure about chainsaws, but when we raced Motocross, we would install the bearing in a new clutch basket by freezing it in the freezer overnight, then it would drop right in.

 

[Stump Shot]

Not sure about chainsaws, but when we raced Motocross, we would install the bearing in a new clutch basket by freezing it in the freezer overnight, then it would drop right in.

While it does not hurt to freeze the bearings, they do not shrink enough themselves, you will still need to heat the cases.

 

[pbillyi69]

i have done it with heat and without. not that i have done a bunch but tye pressing in with bolt was pretty easy and so was using the heat gun. takes about the same amount of time either way. except you dont have to wait for things to cool down when you just press them in.

 

[Tor R]

I heat the crankcases to around 200˚C.
If I have had the bearings in the freezer, I heat the crankcase to around 160-170˚C.

I have seen magnesium shavings in the bearing pocket every now and then in warranty cases, which is why I swear by heat and cold for installing new bearings.

 

[Ketchup]

Make sure you’re applying pressure to the outer race if you press them. Applying force to the inner race can cause premature failure.

 

[Outback]

The old stihl manual had a procedure for cold bearing install too and I heard several people tell me that when they replaced the bearings they didn't run right after that. I always worried that because of magnesiums high thermal expansion rate and its tendency to deform instead of break, more so than aluminum and steel, that they might have been swaging the pocket and then because the seal rides in the bearing creating a bit of a leak when the saw was hot. That's all theory though that I never tested and lots of people get by doing them cold so I just figured I was just being paranoid. I still prefure heat and cold. I chill the bearings too. It just makes since to me that the bearing be as tight as possible and to not invite a spun bearing.

 

[StihlEchoingHusky]

Hell boys...I use a damn torch sometimes. No need to overthink it.

Well if my 3 time doctorate's degree in sheet luck has taught me anything of use is. Anxiety! I fear I'll end up applying my extensive research into someone else's saw.. the heat is the only big thing I fear when it comes to working on saws

 

[Sloughfoot]

I don't heat my cases when I install a bearing. I put oil on the outside of the race and in the pocket and then use a bolt with about 8 washers and a nut. I tap the bearing into place to make sure it is barely started and flat then I put in the bolt with four washers on each side and then the nut and then use two sockets to work the bearing into the pocket. If the bearing recesses a little on the inside, I make sure I use washers that are smaller than the pocket so they are easy to get out. No heat needed, therefore I won't burn myself. I work slowly to make sure it stays straight, if I get the hee-bee gee-bees that something is not right, I can stop and reset to make sure things are going well. I have done about five cases so far this way (all the way from a Husky 55 up to a 575 and have not had an issue so far). Not sure about the motoseal.

How do you get them on the crank?

 

[Tor R]

For those who are skeptical about using heat.....
I have been heating crankcases for 10 years now, and I definitely will not change the methodology.
On the 5xx series I have seen magnesium shavings in the bearing pocket too often, that is, the factory fails to cold press the bearing in place. Needless to say, they had a short life.
On the nylon cage series, they are in the freezer overnight, I prefer about 170˚C, gives me a few seconds extra time to dump the bearing in place in the pocket.
I am very quick to get the crankcase back to cool down quickly, and oil in the bearing since heat & cold can cause condensation.
I have Husqvarna's service tool to cold press bearing in place, expensive tool set, and it is still unused!

 

[Outback]

Yep, I keep a bottle of whatever 2t oil I've gotten with other saws purchases that I don't want to use for mix on the bench and pour a cap full in the case on both bearing sides and usually a little on the crank big end, some on the wrist pin bearing when it goes in and smear around the cylinder. I think of it like assembly lube for any other engine. That way when I start her up she puffs a little smoke but I know nothing started its life dry.

 

[StihlEchoingHusky]

Yep, I keep a bottle of whatever 2t oil I've gotten with other saws purchases that I don't want to use for mix on the bench and pour a cap full in the case on both bearing sides and usually a little on the crank big end, some on the wrist pin bearing when it goes in and smear around the cylinder. I think of it like assembly lube for any other engine. That way when I start her up she puffs a little smoke but I know nothing started its life dry.

Ive got one of those industrial chemical spray bottles from Lowes that I keep full of either lucus 2 stroke or something of similar price for quickly cooling things down

On the nylon cage

No damnit.... Idk Im just not a fan of nylon cages. Stihls Pto being primarily proprietary drives me up a wall as is. Anytime I change a bearing on whatever I look to see if where I get nachi has them first.

 

[Tor R]

No damnit.... Idk Im just not a fan of nylon cages. Stihls Pto being primarily proprietary drives me up a wall as is. Anytime I change a bearing on whatever I look to see if where I get nachi has them first.

There is no weakness with proprietary nylon bearings, they have been around for 27 years in Husqvarna saws, 351 was the first model to get one.
Nowadays they are the first choice in professional saws, hobby saws get traditional metal cage bearings!

 

[Mastermind]

Well if my 3 time doctorate's degree in sheet luck has taught me anything of use is. Anxiety! I fear I'll end up applying my extensive research into someone else's saw.. the heat is the only big thing I fear when it comes to working on saws

Ive got one of those industrial chemical spray bottles from Lowes that I keep full of either lucus 2 stroke or something of similar price for quickly cooling things down

No damnit.... Idk Im just not a fan of nylon cages. Stihls Pto being primarily proprietary drives me up a wall as is. Anytime I change a bearing on whatever I look to see if where I get nachi has them first.

Scared of heat. Scared of nylon.

Who hurt you?

LOL

 

[cus_deluxe]

im way too impatient to wait the minute or two the heat gun/torch takes. typically i would not heat the case enough, get bearing stuck halfway etc. now i just press em into the case and use mattyos tool to pull crank into bearing.