Anyone know much about these gearboxes?

I have one in an 2002 Audi A6 2.5 tdi 155 that feels like it doesnt know when to change gear, and judders??
Juddering starts when a normal gearbox would change up from 1st to 2nd, then at contant rpm/speed, you get a drop in rpm of abou 500rpm, then it rises back to normal level as if its slipping or trying to "change gears"

I know its a CVT based gearbox, which is seemless, and has 6 "gears" to make it feel like a normal gearbox, but do these gearboxes need a regular gearbox oil change?

Anyone know what type of oil?

My local Audi dealer is completly useless, and doesnt know about this gearbox!!!!

All the auto gearbox people i've spoken to don't want to know!!!

Anyone shed an glimmer of light???

Thanks in advance.

 

It's supposed be "non-serviceable" in that you don't change the oil.
The shuddering is a common problem with the software more than the actual tranny. Most dealers will re-flash the tranny computer, and if that doesn't cure it (which most of the time it doesn't), I've heard of them just replacing the tranny altogether.