What causes gears to bite??

[snicko]

Thats a while in the gearbox... Wonder if you had dropped the vmx-m and replaced it again with vmx-m if it would have been better or stayed like it was. Sometimes a diff need a few oil changes before it comes good... Don't matter now though....

Actually thats a good idea. In how may K's do you think I should get it changed again?

[mudski]

I would have thought no more than 50 thousand. I just change mine every 12 months religiously and thats around 30k...
Its like changing engine oil brands. You need to run the one type for a few changes before the motor settles to it. You can't change the brand of oil once and decide if its better or not straight away. I went from Magnatec to the Dello. Instantly my engine was noisier and the catch can was catching around 75ml of more oil. I left it for a few changes, its settled down in the catch can side of things but the motor was still a little noisier than before but I decided to go back to Magnatec as I can get it cheaper than Dello and the Magnatec is a higher quality of oil the the Dello. (flame proof suit is on...) And the initial start up noise is a crap load quieter again. But I persisted with three oil changes before I made the decision.
So after seeing BA change his diff oil a few times last year when he had rear diff noises he said it finally settled after a few oil changes. It obviously needed a good flush out.