Axle questions.

[thimes86]

I have a j30 diff with 5 bolt axles, it works properly when not bolted to the axles but when i hook up my axles to the diff, it makes it work like an open diff. Why is this? and how can i go about making it work right? From what ive read its because i have the wrong axles and i need vlsd axles. Is that right? and if so how can i tell what axles i need to get?
Thanks!