Drop in revs when slewing to the left?

Hi there,

My komatsu PC30mr-1 drops revs just a little bit when slewing to the left, the revs don't pick up till i slew to the right for a bit.

I wasn't to worried about it, its only a slight drop and doesn't really affect performance, but thought i would ask in case it is a sign of something bad to come.

Its an old machine and they don't make a lot of parts for this model, so if a major part is on its way out it would be good to know.

I called komatsu they didn't have a clue.