Dex210 slipper issues

[danny the elfman]

Heys guys. Im having a lot of trouble with the slipper clutch on my 210. On the track last nigt I was getting a huge amount of slip. The diff is good, ive taken that out, put two drivers in the outdrives and couldn't slip the diff gear. So should be an easy fix right? Just tighten the slipper and off I go. But the slipper spring is already at full lock and I can turn the spur with one finger. What can I do? Is it the sring thats the problem? Dont know what else it could be. Thanks for reading