Claas header knife breaking

[Zippy768]

Dominator 108, had it 4 years and always had a bit of a knife issue.
The knife that came in it shook sections off for a past time. We replaced a few sections and re-riveted any dodgey ones and was still a problem. I assume it must be bent.
Used the spare and went well until breaking the head off.
Picked up a bolted knife from combine graveyard and managed to fit and get working. End of last season the head broke off!!
Had a new rocker arm mid 2017 harvest and a replacement wobble box mid 2018 harvest.
Where should I be looking for the cause?
Are guides worn? Or something else?

The bolted knife has sections that claas couldn't match up (not sure what the knife came out of). Claas guy told me I shouldn't had been able to get a bolted knife in without changing guides and everything etc

Tia

 

[principal skinner]

Tight fingers? Blunt edges on fingers? Blunt sections? Need to check the play in the wobble box, pop the belt off and rock the pulley you will soon see if it’s a bit loose in there

 

[fredf]

Has the ball on the ball joint any were (spelling)? this will brake the knife end very quickly and very thing written above.

Tom

 

[Hesston4860s]

Is the header bent ?.

 

[bobk]

Dominator 108, had it 4 years and always had a bit of a knife issue.
The knife that came in it shook sections off for a past time. We replaced a few sections and re-riveted any dodgey ones and was still a problem. I assume it must be bent.
Used the spare and went well until breaking the head off.
Picked up a bolted knife from combine graveyard and managed to fit and get working. End of last season the head broke off!!
Had a new rocker arm mid 2017 harvest and a replacement wobble box mid 2018 harvest.
Where should I be looking for the cause?
Are guides worn? Or something else?

The bolted knife has sections that claas couldn't match up (not sure what the knife came out of). Claas guy told me I shouldn't had been able to get a bolted knife in without changing guides and everything etc

Tia

Buy a new knife . ... life's too short

 

[robo]

make sure the knife throw is correct centre of section to centre of finger or as above make sure no wear in the ball joint

 

[Zippy768]

Tight fingers? Blunt edges on fingers? Blunt sections? Need to check the play in the wobble box, pop the belt off and rock the pulley you will soon see if it’s a bit loose in there

Ok, lots to check there. Wobble box seems sound. I was wondering if it was just general wear on the guides causing too much slack.

 

[Zippy768]

Has the ball on the ball joint any were (spelling)? this will brake the knife end very quickly and very thing written above.

Tom

make sure the knife throw is correct centre of section to centre of finger or as above make sure no wear in the ball joint

Ball joint is sound. Was replaced with the rocker arm.
I'll double check the throw. But pretty sure its centre to centre. One spline out on the wobble box shaft would throw the knife wildly out

 

[Zippy768]

Buy a new knife . ... life's too short

I am........thought I would try and find the cause - prevent my new knife becoming two parts

 

[robo]

might be worth speaking to mark at JMT Engineering at Ladbroke Warwickshire