Mini Digger won't track straight

[HeliPilot]

Hi All
My JCB 8026 has stopped tracking in a straight line, one track is running much slower than it should.
Any suggestions where I should start first?
The machine has only covered 500hrs of relatively light work.

 

[diggerjones]

Check for shite around the pedals

 

[HeliPilot]

Check for shite around the pedals

I have got full travel of the pedals.

 

[CPS]

Has it started doing it since your Tiltrotator has been fitted? Is it a case the that the hammer line is getting flow? Causing one track to go slower?
Does the auto idle work?