Sealed bearings instead of Open bearings ? Can I ?

[simonUK]

So basicly I bought a used crank off ebay it came with new bearings but the bearings are sealed no like the stock ones.

Am I ok to use the sealed ones or with ethanol/petrol eat away at them ?

Thanks in advance

Simon

 

[Jacob J.]

If they're just generic sealed bearings like SKF, pop the seals out and you're good to go. If it's a bearing that has an integral oil seal like the PTO side bearing for a Husky 575/576, then install it as is, seal facing outward.

 

[stinkbait]

I rebuild a saw engine once with sealed bearings. I couldn't find crank seals because they were the craziest things ever. Anyway, I just popped the inner seals out, to allow mix to enter, and let the outer seals act as crank seals. Worked perfect.

 

[pioneerguy600]

opcorn:

 

[Roanoker494]

I rebuild a saw engine once with sealed bearings. I couldn't find crank seals because they were the craziest things ever. Anyway, I just popped the inner seals out, to allow mix to enter, and let the outer seals act as crank seals. Worked perfect.

Now that is a interesting idea, I believe a little REP is due.

 

[pgg]

Well, I've tried the same, and no way Jose.. Tested the seal with a vac-pump and soapy water - the air pisses clean thru the seals from one side to the other on a "standard" sealed bearing... all the seals do is keep the grease in.


Proper husky type chainsaw sealed bearings are totally different from a normal sealed bearing because they also have a separate integral seal that seals onto the crank as well

 

[67L36Driver]

Pop the inboard seal off the bearing. You can leave the outboard on it but install the normal crank seal anyway.

If you leave both seals on it with just the factory grease, the bearing will overheat at the speeds the saw crank turns. Fuel/oil mix wash over the bearing and keep it oiled and cooled. You do not want the bearing to seize and ruin the crank and/or the housing.

 

[SkippyKtm]

Whenever I get sealed/shielded bearings like that, I pop both seals off, flush the grease out, and apply my usual mix oil as assembly lube.
However, I did see one saw it was an old 044 I believe, that had metal shields installed on the inside of the bearings. I was doing top end work on it, and I always check the bearings and seals while I'm at it, and the bearings were holding up fine. Now there probably is a difference between a rubber seal on a bearing and a metal shield though.

 

[67L36Driver]

Whenever I get sealed/shielded bearings like that, I pop both seals off, A: flush the grease out, and apply my usual mix oil as assembly lube.
However, I did see one saw it was an old 044 I believe, that had metal shields installed on the inside of the bearings. I was doing top end work on it, and I always check the bearings and seals while I'm at it, and the bearings were holding up fine. Now there probably is a B: difference between a rubber seal on a bearing and a metal shield though.

A: Don't bother, you likely introduce more contaminates.
B: A shield is pressed in the rim of the outer ring and clears the inner ring by .005"-.010". A seal rides on the inner race.

 

[Terry Syd]

Besides eliminating any friction, the gap in the shield will allow the oil in the mix to pool inside the bearing. On some two-stroke engines a 'sealed' bearing is used to increase crankcase compression. The volume inside the bearing is eliminated from the overall crankcase volume.

Edit: Well, looks like the search function is working. Here's a thread I started on using sealed bearings to increase crankcase compression - http://www.arboristsite.com/chainsaw/141737.htm

 

[Jacob J.]

Stihl used some sealed bearings as an experiment to help protect the bearings from exposure to contaminants. It didn't work out and Stihl engineers chose to go back to open bearings. We even got a letter about it at the dealership I worked at.

 

[almondgt]

I never tried sealed bearings and would not. Bearing job is time consuming and at the heart of the saw. Put in the right stuff the first time and forget about it. Go OEM or don't go at all IMO. :chainsawguy:

 

[Tohya]

Stihl used some sealed bearings as an experiment to help protect the bearings from exposure to contaminants. It didn't work out and Stihl engineers chose to go back to open bearings. We even got a letter about it at the dealership I worked at.

Do you remember if it was it because the sealed bearing failed quicker or that there was not enough of a change to make it worth the extra cost?

 

[farmhard]

Do you remember if it was it because the sealed bearing failed quicker or that there was not enough of a change to make it worth the extra cost?

I'm thinking of leaving the outer dust seals in a blower. They always blow the one bearing. Whether it be imbalance or dirt IDK but the seals aren't always that tight either.

 

[MacAttack]

First one here to say.... NECROTHREAD!

 

[Jasonrkba]

2011

 

[Chevboy0167]

 

[farmhard]

First one here to say.... NECROTHREAD!

Kudos to the OP it's still relevant.