I got a product from Nissan a few years ago right in their service department. I spoke with the mechanic that gave it to me....He explained that this product specifically softened up the o-rings and seals in their transmissions and would restore function. I hummed and hawwed over getting this stuff cause it was so darn expensive, but tried it, and to be honest I did'nt notice anything different, in function of the trans itself but it did cure a leak, I think......but the point is, that there is a product out there that will attempt to help you..... if indeed the o-rings have become stiff.

I wonder if this problem you are having is related to the adjustment of your throttle or bowden cable. I am having similar problems with the 420 sel that we just transplanted an engine tranny combo into and that is what I was searching for when I came across this thread.

Anyone have a link to proper adjustment of the linkages for the 420sel throttle and trans. cable adjustment?