Husky 357xp Clutch overheating

[spudulike]

The top pinion is a 346 one....part code 503 89 21-02

The lower one - I can't see the code on it.

[Frazer Burley]

13 minutes ago, spudulike said:

Correct part code - 503 91 27-02

So is that the crank fooked and wanting replaced? that the cause of the woes?

 

Wear on the side case is from when a clutch spring broke and a part of it jammed between clutch and side case. Know so as when I took it off to see what was up there it was jammed.

 

Thanks for the caliper lesson 👍

 

14 minutes ago, spudulike said:

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]

I measure the crank in three places and 0.25 of wear is well and truly fooked, 0.15 is on its way, 0.1mm with pitting is ....fit a new bearing, check the drum bearing surface for wear and see what it feels like.....it is not going to get better, that's for sure and is on its way.

I don't know the nominal measurement of the crank - Husqvarna don't come up in nice round metric figures!

Warning to others - a good regular service by someone half decent.....or a regular new bearing would have saved this happening.....expensive lesson!

I can't be 100% sure it is the cause of the spring issue. Unlikely but something has been causing it.

Edited March 20, 2022 by spudulike

[Frazer Burley]

2 minutes ago, spudulike said:

I measure the crank in three places and 0.25 of wear is well and truly fooked, 0.15 is on its way, 0.1mm with pitting is ....fit a new bearing, check the drum bearing surface for wear and see what it feels like.....it is not going to get better, that's for sure and is on its way.

I don't know the nominal measurement of the crank - Husqvarna don't come up in nice round metric figures!

Warning to others - a good regular service by someone half decent.....or a regular new bearing would have saved this happening.....expensive lesson!

Cool I'll give it a measure but looks likely the pitting is the end of it.

 

Yeah I bought the saw used not too long ago so the damage may have already been done...

 

Thanks for help

[adw]

I have seen plenty of worn cranks from insufficient drum bearing lubrication and constant miss use of the chain brake, but certainly not enough to cause the clutch springs to break, did we see where the springs have broken?

[spudulike]

I always think the lubrication isn't of great importance as most of the lube is thrown out during the first few minutes of work, I do however lube the needle bearing when in the workshop as most would. The 3120 is different as I am sure my friend ADW will tell you all.....we do get on, he is a good guy and mean no harm.

Most of the damage is done by not bothering checking the bearing and drum to the point a little play becomes really terminal taking out the drum and then the crank. 

A yearly check or changing the bearing every rim and drum check/renewal is the answer.

[Frazer Burley]

21 hours ago, adw said:

I have seen plenty of worn cranks from insufficient drum bearing lubrication and constant miss use of the chain brake, but certainly not enough to cause the clutch springs to break, did we see where the springs have broken?

Clutch springs broke at the end of the coil. Also a tip of a shoe broke on one occasion!

 

hardly use chainbrake unless on really sketchy ground so doubt it’s that. 

[adw]

This is fast coming down to excessive vibration, or poor quality springs in my opinion, I just cannot see a bit of wear on the crank journal causing this.

[spudulike]

14 minutes ago, adw said:

This is fast coming down to excessive vibration, or poor quality springs in my opinion, I just cannot see a bit of wear on the crank journal causing this.

Pretty much agree with this, I have seen a few worn crankshafts without these issues.

[adw]

I am just trying to think why you couldn’t fit a 254 clutch on it, I will try it when I get a minute.