773 Chain Noise?

[sawright]

I have an 02 773G with 1200 hours. It has Grouser OTT. When traveling under load, like pushing up an incline with a full bucket of clay, I hear a rumbling sound that sounds like its coming from the chain box. Not real loud, but noticeable when operating at 3/4 throttle. It does not make the sound when traveling under light load, maybe just a quiet chittering, mostly when turning right (using left side final drive) at high speed. Any thoughts as to what this might be, whether I should be worried and how to diagnose it? Thanks, Steve

 

[Chandler]

My 01 (480 hours) does the same thing. I was concerned myself but was told that some chain noise is normal. I wonder why it does it on that side though. Main thing is to keep the chain case full of oil.