Worrying noise

[Bertha's Dad]

I recently had the offside swivel ball assembly serviced by my local garage, as it was leaking axle oil badly. Since then, my ZD30 seems to have developed a worrying noise. When the engine is revving under load, I get a 'chattering' noise, which sounds as if it is coming from under the transfer lever. This is most noticeable when the autobox changes down out of overdrive at motorway speeds, to climb an incline or overtake.
Any clues please. Would this be connected to the work done on the swivel ball components?

 

[solarman216]

The only connection between hub and box is the drive system, so if you have manual hubs did the garage leave them "locked" if so unlock them, or maybe you have fixed hubs in which case remove them and take it for a drive and see if the noise stops, to do the oil seal they will have removed the CVJ in the hub, as it is "open" ie no boot on it it is possible they have introduced some contamination causing it to be noisy, disconnecting it will prove it one way or the other, Rick