Which weight of Hypoid?

["Mik Tip" <miktip@worldnet.att.net>]

In my 86 Coupe GT, I rebuilt the gearbox, after having shifting problems.
Inside the gearbox I found the right side differential bearing worn badly
as well as the race.  Plus the ring & pinion were worn very smooth!

In the rebuilt gearbox, I utilize the recommended 80W-90 gear oil.
But I feel, I should run 85W-140, hopeing the heavier weight 
oil will aid in slowing down the internal wear of the gearbox.
Especially with the higher HP's of my "not-so-stock" engine!
(The rebuilt gearbox shifts fine now!)

I'm curious if any other Audi types run the heavier weight oil,
or have some inside scoop about pro's & cons of utilizing the 
heavier weight oil?

All comments and sugg's welcome!

                              Mik