Husky 357xp Clutch overheating

[Frazer Burley]

Hey folks

 

Trying to solve the chainsaw qualm of the month...

 

Got this saw off marketplace.

Ran fine for 6 months of part time professional use. Happy camper.

Then broke clutch spring. Thought nothing of it and replaced it along with needle bearing that was shot.

Did a few hours work then another broke shortly after. Weird. Maybe it was 'cause I didn't replace all three. Replace all three.

Does another few hours and then another to go. Replace clutch assembly OEM part with three new springs in.

Bit more work spring breaks. Head scratching really begins. Maybe drum is worn? swap out for drum off 346 that seems to have less play in it.

Bit more work. Spring breaks. Notice that the clutch is really hot. This is propbably the issue....(?)

 

What could be cause?

 

I've...

New needle bearing (greased with Husky grease)

Good Clutch Drum (cleaned, no dirt/grease)

New Sprocket

New clutch assembly and springs (full set)

Chain not overtight

Brake band not contacting clutch drum

Saw runs at full power both in and out of cut (clutch not noticibly slipping)

Bar oiling as normal

 

Only thing I can think is worn crank shaft allowing play in the whole system causing heat build up? But shaft looks fine and no ribbing or noticeable damage from fried needle bearing.

 

Any ideas would be bloody amazing!

Cheers

[spudulike]

Are the bearing and drum OEM or aftermarket? I have noticed the aftermarket springs are pretty iffy at best so the first few may be just that.

The clutch will only get really hot if it slips when under load and when knocking the chain-break on at full tilt a few times. If the clutch is good then it really shouldn't get hot enough to damage springs in normal use!

If the crank was worn, it would show in the drum being wobbly. If the crank was bent, the saw would vibrate like mad if it did run at all, If the main bearing was shot, the machine would rumble badly and you would feel it if you moved the clutch around.

 

Bit baffling but be assured, there will be a reason for the issue, you just have to find it. Put some pics up of the clutch cover inside and the assembly....it may tell us something.

 

[Frazer Burley]

Thanks for the reply Spud. I’m away working but will post photos when back home on the workshop and see if I can illuminate the issue. 
tbc…

[adw]

Springs breaking after a few hours is very odd, , do they always break on the ends? high vibration can cause fatigue breakage of the springs, yes lets see some pictures, is this saw on .325 or 3/8 chain? bar length?

[Stubby]

Is the drum worn too thin allowing the springs to over extend to make the shoes bite ? 

[spudulike]

It is usually the clutch that wears and can cause spring issues like this. Drums tend to get two ridges worn on the inner surface and in bad cases, they can burst which isn't nice

The inner drum surface should be checked as well as the outer friction part of the shoe and these should be flat. Real old ones form two humps on both edges of the shoe.

[Frazer Burley]

Hey folks thanks for replies. Got into it today along with 346 that isnt working but I'll leave that for another topic...

 

Adw - .325 chain on 17" bar

 

Stubby - Looks like no signs of excessive wesr on drum or shoes (i.e. no ridging)

 

So I took some pictures that might help although I'm still baffled.

 

One thing I did find was a little pitting/abrasion on the crank shaft. Also the oiler drive sproket is different from other ones I've seen but saw oils fine... And some weird marks on the chainbrake band but looking at my other saw there is similar.

 

Any ideas be great thanks

[Khriss]

Shot in the dark here - wrong oiler sprocket on it pushing clutch out 🤔 K

[spudulike]

The hardened surface of the crank is breaking down so the bearing hasn't been changed often enough. I have scrapped 346s like this as a new crank is £££+

There is wear on the clutch cover where the clutch sits. This is due to the clutch spinning off when the saw de-accelerates. I find it happens on Husqvarnas more so than Stihl and usually take procedures to stop it happening. It is somewhat strange that the semi circular bit in the middle of the cover hasn't worn. It is possible that the damage was caused but the work crankshaft/broken clutch spring/worn clutch rather than the clutch spinning off. If it had spun loose they often re-tighten clamping the oiler pinion and not meshing with it causing damage.

Lastly, measure with the ground end of the verniers!!

[spudulike]

8 minutes ago, Khriss said:

Shot in the dark here - wrong oiler sprocket on it pushing clutch out 🤔 K

Correct part code - 503 91 27-02