Center dif question on slash 4x4 from a new-b

Just replaced slipper with center dif and put sway bars. Truck turns wide now at high speeds, at least it does on the street, haven't had a chance to make it to the local track due to weather... My question is, is this because I left the 100k oil in? All hobby shops were out of 50k and I've read a lot that you should use 50k. Will 50k help solve this?

It really depends on how your sway bars are adjusted and how high your a arms are. Turning at high speeds isn't usually successful for most RC's also. Hope this helps!