Got a weird one with my yanmar sm475 tractor!

[ClutchMeHere]

Getting a light clinking and tinkling sound from the rear end. It only happens under heavy load (pulling the box blade, digging) and when the left wheel starts to spin a bit.

Here's the kicker: it stops when I lock the diff, even if both wheels spin. Also, the left side always seems to break loose first.

Anyone know what this tinkling could be? Not sure if it's new or just a louder version of old, strange noises. Help!

 

[Bidz38]

Based on your description, I imagine it really concerns your differential.
The sounds could be worn spider gears or their bushings, or perhaps something loose within that assembly on the left side, especially if that's the side always breaking loose first.
When you lock the diff, you're essentially bypassing the differential's normal operation, which would explain why the sound stops.
I think you should get it checked out before it becomes a bigger issue!