Shifting gears feels rough

Originally Posted by JARblue

BTW, OP...

I responded to your post on the differential fluid DIY thread. You do not need an extra quart (2 is fine) for the diff fluid. However, the transmission fluid calls for 3 qt, and it is recommended that you get an extra. The fluid you're pumping into the transmission should come out the fill hole when full.

Originally Posted by Bad Boy

Z1 begs to differ, it says I should get an extra...?

Originally Posted by Z1 Website

2 of these 1 quart bottles needed to change the fluid in your differential. If you are removing the rear cover, we recommend purchasing a third bottle as the actual capacity of the differential is 2.25qts. During a drain and fill you will never be able to completely empty the differential so 2 bottles is sufficient.