Rear axle shudder on turn from start
 

I have a TrueTrac in my 7-5/8 and have recently been noticing a shudder on slow turns from a start now that it has gotten colder and I have removed the summer only tires. The changes may just be a coincidence. Up til now it's been great through 5 AutoX events and 4K hard street miles. It's only a year old.
Been using reg Valvoline gear oil and it's clean and clear. Put newer all season tires on, but didn't really notice a difference. For a diff that's advertised to be like an open rear end until a variation in wheel speed is noticed, it's almost like driving with a spool and street tires. Any ideas?