Screaming 361.

[rorymoon]

A while ago my 361 started makeing a sqeaking sound now and then, recently it has become near non-stop the best way I can discribe this noise is like a slipping fan belt.

I have given the saw a good clean and replaced the clutch bell and needle bearing as this is the area of the saw the noise seems to be comeing from but this dosent seem to have helped and can find no signs of anywhere that could be the cause- rubbing from parts that shouldnt contact ect.

The noise only happens when the saw is on tick over not when being used and not allways if the chain brake is off but all the time when it's on.

I hope it's not the bearings , so any other ideas would be gladly received.

 

Many thanks Rory.

[Tom D]

Worn clutch springs, allowing it to bite a little early, turn the idle down and see if it stops, if it does that could be the problem.

[spudulike]

Possibly the clutch side crank bearing - these usally scream when the saw is revved - have you lubricated the clutch bearing? have you checked out and greased the oil pump although it sounds like clutch or crank bearing to me:thumbdown:

 

The crank bearing on this side generally goes first as it is the one that gets the stress of the chain etc.

 

Have you tried tightening and loosening the chain?

[rorymoon]

Sadly I have done or tried most of the above, will try greaseing the oil pump tomorrow tho.

The clutch is fairly new and tight so very unlikely to be the clutch springs but will have a play with the tick over as well just in case.

Thought it might be the bearings as I have tried most things allready but would like to eliminate all other routes before going that far as getting old bearings out is one of my least favorite jobs:thumbdown: is there any easy-ish way to do I'v tended to use a bit of heat and lots of tapping with hammer and shift?

What ever it is I'v got to get it sorted I'm sick of my saw screaming at me evey time I put it down running.

 

Cheers all Rory.

Edited December 11, 2011 by rorymoon
missed words

[spudulike]

Sadly I have done or tried most of the above, will try greaseing the oil pump tomorrow tho.

The clutch is fairly new and tight so very unlikely to be the clutch springs but will have a play with the tick over as well just in case.

Thought it might be the bearings as I have tried most things allready but would like to eliminate all other routes before going that far as getting old bearings out is one of my least favorite jobs:thumbdown: is there any easy-ish way to do I'v tended to use a bit of heat and lots of tapping with hammer and shift?

What ever it is I'v got to get it sorted I'm sick of my saw screaming at me evey time I put it down running.

 

Cheers all Rory.

 

No easy options my friend, split the crank cases - a feat in itself sometimes, once split with the crank removed, use either a big bench vice or a large G clamp to remove - I usually rest a suitably sized socket on the outside part of the ball race and add enough pressure to get the thing moving - don't over do it and good luck - the biggest job you are likely to have to do on a saw:thumbdown: Take care with the mating surfaces - damage may cause air or oil leaks!

 

A constant pressure is better than walloping with a hammer, a press would be ideal but not the sort of thing likely to be found in the average workshop.

[GardenKit]

Sadly I have done or tried most of the above, will try greaseing the oil pump tomorrow tho.

The clutch is fairly new and tight so very unlikely to be the clutch springs but will have a play with the tick over as well just in case.

Thought it might be the bearings as I have tried most things allready but would like to eliminate all other routes before going that far as getting old bearings out is one of my least favorite jobs:thumbdown: is there any easy-ish way to do I'v tended to use a bit of heat and lots of tapping with hammer and shift?

What ever it is I'v got to get it sorted I'm sick of my saw screaming at me evey time I put it down running.

 

Cheers all Rory.

As it only shrieks on tickover,i.e, when the clutch is disengaged, it surely has to be in the clutch rather than the main bearings. I would double check that the clutch is not contacting the drum at any point, not only on the engagement surfaces, but also on the side. Even if the needle bearing is good, if there is wear on the crank the drum can wobble and touch the clutch. It can also be held out of line by the brake band once again allowing it to rub. Once the revs increase and the clutch locks up, everything rotates together, hence no noise. Worth another look before pulling the crank apart?

So

[spudulike]

I guess giving it a good old spray of WD40 with the side cover off when it is screaming may tell you whether it is the crank bearings or an external problem - my thinking was that the chainbrake band may be skewing the needle bearing or putting force on the crank bearing making it scream - I wonder if the bearing internal is spinning around the crankshaft rather than being a tight fit - bit of a weird one:confused1:

 

Personally I think I would pull the clutch off and grease all the parts, reassemble and see if the noise goes away or anything changes, if it doesn't then it is internal, if it does, even for a while, then it is external to the crankcase!

[GardenKit]

Might just run it with the clutch removed ( and oil pump worm). I would not want to rev it, but as the shriek is at tickover it may help. If the noise is in the bearings it may still be there ( o.k, I know there wont be any thrust from the clutch) What do you think Spud?

Also check the drum bearing land on the end of the crank, they can wear if used for any time with a failed needle bearing. The reduced diameter allows the drum to rock and could cause the contact between the side of the clutch and the drum.

Worn clutches, especially the early type tend to spread sideways too, but I note that this one seems to be tight.

[Al Smith]

What will happen if you grease a clutch bearing is given enough time the needle bearing will pick up fine dust that will eventually clog the bearing within it's cage .I know it's sounds like a good idea but has proven not to be .

 

If you do have a caked up bearing clean it out with solvent .If the cage is damaged it's best to just replace it .They aren't very costly.

 

A faulty bearing can cause the clutch drum to run eccentric and in extreme cases break a crankshaft ,rare but it can happen . If not it can cause enough vibration that in time it will ruin the crankshaft main bearing which will take out the seal which will cook the cylinder and cost a whole lot more than the original 6-8 dollars US the drum needle bearing would have cost .

[GardenKit]

Sorry Al, just cant agree with some of that. the number of premature bearing failures I come across are all bone dry. The important thing is maintenance, this should be done before the needles get clogged. Wash the bearing with petrol or solvent, regrease with Stihl multipurpose grease and refit.

I do agree that any damaged bearing should be replaced (greased!) as you say they are cheap enough.