stihl ms260 crank bearings

[johnw_123]

hi.

can anyone advise me on why new non-stihl crank bearing would fail the way it has,

 

i rebuilt the saw today and was running through a few heat cycles when it locked up.

 

here is a picture of the bearing

 

thank you john.

Edited January 14, 2016 by johnw_123
picture

[spudulike]

hi.

can anyone advise me on why new non-stihl crank bearing would fail the way it has,

 

i rebuilt the saw today and was running through a few heat cycles when it locked up.

 

here is a picture of the bearing

 

thank you john.

 

Looks like the inner cage broke up. Did you tap the crank ends on both ends when the machine was assembled to loosen the bearings? Was the crank free running after rebuilding? Were the bearings oiled on assembly? Were they the right way round I regards to the race inner shield?

[johnw_123]

agree inner cage has broke up....

no i did not tap crank at both ends....

i had the crank in the freezer over night.

once i put the bearings in the cases then warmed them up wth a heat gun the crank slid in very well and also lubed the bearings(fitted the right way round), once i rebuilt the engine the crank was turning freely.

john

[spudulike]

I would say that either the bearing was substandard/faulty/of incorrect specification or there was still inherent pressure on the bearings from the rebuild and this heated the bearing (I see the paint has bubbled through heat) and done them in.

 

Whenever I have changed mains, the crank tends to be a bit tight once the crank sides are bolted together and this is relieved by tapping the ends of the crank to and fro which generally loosens up the bearings to the point you can turn it easily by twisting the crank ends with your fingers.

 

You are just making sure the bearings are running true in their races rather than having lateral tension within them from the clamping together of the case sides.

 

I reckon the bearings still had tension in them and the heat destroyed one before it could bed in!

 

Other than that - use a reputable manufacture of bearings or OEM!

[johnw_123]

thanks spudulike.

i would like to put it down to duff bearings rather than my mechanics:blushing:

 

i have the damaged bearing in front of me with the original stihl one, the picture shows the stihl one has has a much better inner cage.

 

 

 

thanks again john.

[johnw_123]

Other than that - use a reputable manufacture of bearings or OEM!

 

 

would you know where to go for bearings for a ms260...

 

the flywheel side is not a problem but the clutch side is not so easy to find...it was either original or cheap chinese.

 

 

thanks john.

[Mesterh]

I would only ever use genuine parts for something like that. Way too much work involved to save a few pounds.

 

Unless of course you know for a fact the after market bearings are exactly the same ones stihl use.

[spudulike]

Other than that - use a reputable manufacture of bearings or OEM!

 

 

would you know where to go for bearings for a ms260...

 

the flywheel side is not a problem but the clutch side is not so easy to find...it was either original or cheap chinese.

 

 

thanks john.

 

The bearings will be marked with their inner, outer bore and depth. The issue is when the outer race is double depth and has a seal to push in to it or the bearing is a weird non standard size!

 

There are many bearing online outlets but some bearings are impossible to get from quality manufacturers like SKF .....like MS660 clutch side.

 

Your options are aftermarket or original - as the other poster said - big job generally calls for OEM despite the cost. Just done a MS660, £50 worth of bearings but the job will last for years if the machine is treated correctly.

[NFG]

Other than that - use a reputable manufacture of bearings or OEM!

 

 

would you know where to go for bearings for a ms260...

 

the flywheel side is not a problem but the clutch side is not so easy to find...it was either original or cheap chinese.

 

 

thanks john.

 

Try LS Engineers

 

Search results for: 'MS260 bearing' | L&S Engineers

 

N

[aspenarb]

Spuds on the money with that bearing fail. although not ideal a cheap bearing should have lasted longer than that. Thats definitely a side loading issue.

 

Bob