i have not attempted to shift the 249, its in high and goes when i put my foot down.
i dont know anything about them. i know 231's pretty well.
to me it sounds like i am driving a 4x4 truck on pavement, but no tire chiping or feeling like its bound up, just rotational drive line clunking
slow or high speeds its present. put your foot down with wheel straight it sometimes goes away.
what does the VC do? just bias power to the front or rear like a center diff?