Originally posted by remarcable
That wasn't a case of open diff vs limited slip diff... My 99 outback with open diffs easily climbs such hills. The volvo system just has problems.
you could clearly see the volvo digging a hole with the left front, whilst the left rear did nothing. Unless the right rear was also digging another hole (which I doubt), I suspect that the transfercase was effectively "open" (meaning the font axle could sit & spin, and the rear would get nothing).
The Viscous coupling setup with the manual Subarus (as you probably already know), will let a certain percentage of slip setup, before effectivily locking the front & rear axles. (Meaning you have in effect sometimes only 2 driving wheels.. but those wheels are each on a seperate axle. It looked to me like the Volvo only had 1 driving wheel).
Sorry if I didnt make that clear.