Buzzer like noise JD 670

[Bill Meglen]

My JD 670 emits a buzzer like noise that seems to fluctuate with rpm, but at higher rpm it diminishes. From the seat it seems to emanate from the dash area but when standing at the rear of tractor it sounds like it is there. Can't find any buzzers on the tractor or listed in the manual. Fluid levels all OK. Power take off at rear has Kubota back hoe pump connected but noise exists with power take off not engaged. Any ideas?

 

[MSM]

Maybe a clogged hydraulic filter,or the hydr. pump sucking air,or cold thick hyd. fluid. What you are hearing,is a vibration through the hydraulic lines that resonates through the whole tractor. Feel the hydraulic lines for a vibration.

 

[Bill Meglen]

Thanks! That makes sense. Changing filters is easy enough to try. It was not real cold when first noticed but it is now. Will I damage the tractor if I use it in this condition? Appreciate your post!